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How to get a group of many rigid bodies to start simulation at a set frame
I have a physics simulation in Blender with many rigid bodies. I have a group containing many objects (255). How do I turn off physics simulation on this group of objects to until a certain frame?

Related: http://blender.stackexchange.com/q/2620/599


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Single a single material across several objects with individual control
Is it possible to share a single material across several objects but have control over some aspect of the material (e.g. factor on a fade node) on individual objects. Each object can be associated with an individual FCurve. I am currently building N identical materials for N objects, but its getting old. Thanks.

Select the part of the material that you want to share and make it into a group with ⎈ CtrlG. Use the group in each material with any custom nodes you may want for the object.
Using a group you can connect any inputs you want so that each material can use different values to customize the material for each object, while the nodes in the group stay the same.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


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Download platform specific animation nodes 2.0
I've looked high and low and can not find the platform specific (win64) precompiled AN 2.0 download described in the release notes.
Thanks,
Mike

https://github.com/JacquesLucke/animation_nodes/releases

The platform specific variations of Animation Nodes 2.0 can be found while viewing this release of the add-on via its Github page: https://github.com/JacquesLucke/animation_nodes/releases/tag/v2.0

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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Animation Nodes 2.0 Reload (F8) Not Working
I've downloaded the Windows prebuilt AN 2.0 and installed on Blender 2.78C. AN loads fine on startup and seems to work, but I am doing additional development and when I reload with F8, the following AN error is generated.
Animation Nodes can't be reloaded.
Exception in module register(): 'E:\00visualNotes\workspace\visualNotes\addons\animation_nodes\__init__.py'
Traceback (most recent call last):
  File "C:\Program Files\Blender Foundation\Blender\2.78\scripts\modules\addon_utils.py", line 349, in enable
    mod.register()
  File "E:\00visualNotes\workspace\visualNotes\addons\animation_nodes__init__.py", line 176, in register
    bpy.utils.register_module(name)
  File "C:\Program Files\Blender Foundation\Blender\2.78\scripts\modules\bpy\utils__init__.py", line 618, in register_module
    raise Exception("register_module(%r): defines no classes" % module)
Exception: register_module('animation_nodes'): defines no classes
Any help with this would be greatly appreciated.

Animation Nodes 2.0 does not support reloading.
This is because Python does not support reloading of extension modules, which AN has a lot of since it uses Cython.
So unfortunately you will have to disable AN completely during development or restart Blender every time you make a change.

Is it possible to build with the original python versions of the CPython modules and would this allow reloading?

Another thought... Is it possible for me to create two addons: AN2.0 and MyAddon which imports AN2. Disable reload on AN2 and reload MyAddon.


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Mirrored geometry does not receive the same material?
Node editor is just as below:

I mirror the eye with an empty.
How do I get the same mirrored object?

maybe you should use the 'generated' option for using with the mapping node. Or place the object 'eyes' origin where you put your empty, remove the later one.

Is anyone using this file? http://blend-exchange.giantcowfilms.com/b/484/, or should I delete it? It links to this question

Suggestion
Apply the mirror, separate the eyes, transform origin to geometry, uv map, and apply a circular texture.
I do not think attempting to apply the same texture space of [Object] to both eyes in an easy or flexible idea.  If the eyes rotate you may find trouble.  I do not know your animation style.

Secondary Information , Not a suggestion
Here is deprecated texture mapping without uv with typical sticky style ... it is biased to the vector indicated

If you choose to have bad frozen eyes with a slippery texture this is a bad deprecated node image.

Both images above rely on the spherical shape and have no uv map required.

Also the anwser! Thanks. Thought Mirror Mod would create another eye as a seperate object haha


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Node editor's backdrop and render result are not the same!
The backdrop:

Render result:

Output nodes are correctly connected. Not the same, tho.


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One part of the render layer glowing?

Take a look at this pic. I want only the eyes to glow without the armor glowing too (The armor got a glossy shader).
How can I do that?

One simplistic approach could be to use a color or difference key.


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How do I get these animated obstacles to work right with fluid physics and prevent freak outs like this?
I recently tried to bake a fluid physics simulation with a mixing vat style setup. I did some basic parenting and keyframes to animate the stirrer, but the fluid immediately freaked out completely (or as immediately as it could have been, considering it baked for 3 days).
https://www.youtube.com/watch?v=5Mli_sOjYDc
What settings do I need to change to keep this from happening? I've heard about something called exporting an animated mesh, but I can't seem to find anything on the internet about it.

Select your obstacle object, go to physics in the properties pane, under fluid obstacle settings there's a checkbox called Export Animated Mesh. Use it :-)

There are a few things you can do.

The mixing blade has to much of an impact. Among the obstacle settings, change impact from 1.0 to something like 0.5 or lower. The default setting of 1.0 is almost always too high.
Check the geometry of the vat. Does it get its thickness from the solidify modifier? If so, apply the modifier before baking, or maybe just move it to the top of the modifier stack, before the fluid sim.
In the domain settings, uncheck "remove air bubbles". This may leave a small space between the fluid and the surrounding obstacle, but unless the obstacle is transparent, it probably won't matter.

You might be able to save yourself a few headaches by using a domain the same shape as your container, rather than a generic cube.
Try selecting the inside edges of your container, Shift-D to copy, and build a new domain from that. Be sure to reverse the normals after you do this, and put a top and bottom face on this new mesh/domain.
Once that's done you can enlarge the domain bigger than the inside edge of the container, and shape the top for splash.
Controlling the splash... that requires lots of tweaks, as scale can be a factor for the simulation, as can elements that affect viscosity and mass.

I don't think using any other form except for cube as fluid domain can save some time because it will be treated as cube when computing; same applies for other types of physics sim. It would be possible splitting animation in parts and baking several smaller domains though; as always, efficiency depends on situation.


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How to maintain IK chain angle to target?
I've got a robot assembly arm (http://sendvid.com/ze9l813s) set up with an inverse kinematics solver, but I don't know how to keep the end bone from rotating. I need that bone to remain perpendicular to the Z axis, and to the target, while it is moving. I don't want to use rotation constraints, I just want the IK chain to have the end bone remain totally perpendicular to the ground. How do I do this with inverse kinematics?
If you're having trouble visualizing it, here's a video of what an assembly arm is supposed to work like: https://www.youtube.com/watch?v=J23oqwyN9-A
The arm can move straight up and straight down, not in some kind of weird bendy arc like the Inverse Kinematics rig is doing.

If I am understanding your question correctly, I think this kind of setup would be the simplest solution:

The main point is to disable "Inherit Rotation" for the tip bone.

Extrude another bone from the root of the "Tip Bone" that will be the "IK Target", and clear its Parent (AltP in Armature Edit Mode). It must not have a Parent in order to function properly as an IK Target.


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Color ramp isn't working correctly with particle info node?
I'm animating a spot welder which throws off some sparks (with help from Andrew Price's spark tutorial) and I can't actually get them to change color in relation to their age. Here's my node setup:
The color nodes on the top are all you need to pay attention to. If you look, I've got a color ramp that I tried to use to get the sparks to shift color as they get older, but for some reason it isn't working correctly. The divide node seems to always be giving an output of 1, no matter what the age of the particle is. This means that the sparks only ever have the color of the very end of the color ramp. I've tried moving the left color picker over, even to within about 1 pixel of the right one. It has no effect and the sparks keep the color of the right color picker throughout their entire particle lifetimes. I did also make sure to actually give the particles a lifespan. Does anyone know why the divide node might be giving an output of 1? The age to lifetime ratio should start at 0 and progress to 1.
This is what the rendered scene looks like:

Particles can't change colour along their blurred length, even though, technically, they age while the shutter is open the colour remains constant.  i.e. for the duration of the blur they are rendered as the same colour.  Older particles in the frame should be of a different colour though.  Have you tried a more contrasting colour across the colour ramp?

Here's a demonstration showing just that part of the cycles particle info being used to drive a colour ramp.  Notice I had to also add in another divide just to get the far end of the colour ramp to appear in the view.  You can see clearly that the individual particle blurred paths are constant in colour even though different particles may have different colours.  You might be able to use a spherical gradient in addition to the age and lifetime values to change colour along a long thin particle to create the effect you are looking for.

Here's a crude version of the suggestion above.

Thanks for your answer, but I think I found the source of the problem. I was using time remapping, which does not at all work correctly with the particle info input node. It causes completely unexpected behavior, with particles fading out too quickly. I posted a better, more detailed question (with a video) recently.


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Change image levels quickly
I have an image with a few shades of grey in it. I need to change some of those shades into white. Is there anything more efficient than going through each pixel one by one and check its RGB values? Is it perhaps possible to somehow posterize the image with some built-in function?

Blender is a bit limited as an image editor, you may find using an external image editor easier. One option is to use the compositor were masking nodes can be used to select a colour to use as a mask for other nodes.
As your asking with the tag of python, you can access the raw image data through bpy.data.images['img_name'].pixels[x]. This is a list of floats that makeup the pixel data, there are 4 per image pixel (red,green,blue,alpha). You can get the width and height through bpy.data.images['img_name'].size.
for p in bpy.data.images['img_name'].pixels:
    if p < 0.45 and p > 0.48:
        p = 0.2

Yep, this is what I meant by "going through each pixel one by one". I already have that working but was curious if there was anything more efficient than that.

It's possible that installing a module like pillow either into blender's python or get blender using a system python install can offer compiled C code that runs faster and has specific functions to use. If your after distributing an addon that's probably not a popular option.


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How to get full file path to rendered image?
I need to get full, absolute path to the image that has been rendered. Unfortunately bpy.path.abspath() returns only the folder path and not the disk. Same with all the other path functions - no disk.

Could it be something like
os.path.abspath(os.path.join(bpy.path.abspath("//"), bpy.context.scene.render.filepath)). I'm just no sure of what you get with that function alone.

Your code appends the D disk to the path (probably because my Blender is running from D) instead of C, to which the render is saved (specifically to C:\tmp\render.png)

There's a utility function:

frame_path()
  RenderSettings.frame_path(frame=1)
  Return the absolute path to the filename to be written for a given frame

scene = bpy.context.scene
path = scene.render.frame_path(scene.frame_current)

Still not 100% correct. For some reason shows me a slightly different file name. My script generates a render filename and then puts it in bpy.context.scene.render.filepath (just before rendering). The name contains a "#" but when I call scene.render.frame_path(scene.frame_current), it changes the "#" to "1" for some reason. But at least, I guess, I can get the folder path (with the disk) and then manually append the filename. Will try that

Blender fills in '#' in the output filename with the frame number that was rendered. To get a specific file you will need to know the frame number that you are after.

I only render one frame at a time (it's not an animation). The "#" has to be there as it is because the images will be later on fed to another application which requires this character in filename

OK, I got the absolute folder path from that scene.render.frame_path(scene.frame_current) and then managed to replace the filename with the one I'm generating and now I have the full, correct path!


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Animation Nodes: Merge spline points
I have been trying to use Animation nodes to create splines on certain edges, as can be seen in this question. It is working, but I am running into a problem: The splines that are generated by the Splines from Edges node are not connected to each other. Their points overlap, but do not connect. When given a bevel object, there are gaps at their corners, and the shading cannot be smoothed.

I need a way to remove these double points. If they were mesh, I'd use 'Remove Doubles', but such an option does not exist for Splines. And if I convert to mesh, remove doubles, and then re-make the splines from edges (all via nodes), it re-creates the same problem.
Is there a proper solution to this in animation nodes?

The problem is, spline can't branch, so a vertex that is connected to more that two vertices will cause ambiguity in computations. A possible solution is to divide the mesh into parts that form lines, for each part, topologically sort its vertices and create spline out of it. This of course will not be easy to do and will be computationally expensive. I may try to implement that in the node itself at some point. While I don't have a lot of time now, I will do my best to try to answer your question soon.

I'm fine if it's mesh and then tubes instead of splines if that is easier.

The same algorithm will still have to be done. So it won't be any easier.

How about Mesh and then use the Skin modifier? That works on branched vertex chains.

That might work, and will probably give better results. There is some work to be done still. But it is much easier to do that our original approach, will write an answer using this method, and the other when I get the time to research it further.

Great! One complication for that is the need to mark some sort of root point for Skin modifier.

I realize that, but no worries, it is solvable. Sorry I didn't have time to write the answer yesterday, was updating my answer on the referenced question.

No rush, your answers are excellent!

Spline From Branche
Starting from version 2.1 of Animation Nodes, the Splines From Edges node has a new method called Spline Per Branch which minimizes discontinuity by combining the vertices of each branch in a single spline. Below is a comparison between the Splines Per Edge (left) and the Splines Per Branch (right) methods:

Skin Modifier
The author suggested using the skin modifier to solidify the filtered edges from the referenced answer. Most of the work is handled by Blender's skin modifier. This, however, imposes certain difficulties. Each of the following sections will concert with one of those difficulties.
As a study case, we shall use the example from the referenced answer. This example filters the edges by Freestyle Marked Edges such that the node tree only outputs the edges that are marked as freestyle:

Vertices
You might have noticed by now that we can't output the filtered edges directly, this is due to the fact that the skin modifier will also skin individual vertices, that is, vertices that are not connected to any other vertices through edges. Such vertices were introduced because their edges may have been filtered (removed), so we should also filter vertices so as to only keep the vertices that are used by the edge list.
I will first initialize a boolean list of length number of vertices that we will use to filter the vertices where the the corresponding boolean to each vertex is True if it was mentioned in one of the edges and False otherwise. I chose to initialize all the booleans to be False by default, the significance of this choice will become apparent in a moment. The code to generate this list is:
BooleanList.fromValue(False, len(vertices))

Next, I will loop over the filtered edges, set the booleans at the indices they carry to True and reassign the list. After the loop is done, all the elements that are referenced in the edges will be true and we will have our filtered list. The implementation is simple and is very similar to the loops iterator loop in my answer in the referenced question, so head over there if you want more detailed explanations:

And you can see that the vertices we have are indeed the ones that are part of edges:

Edge Indices
The foregoing section introduces a problem, since we removed some vertices, the vertices indices changed and subsequently the edge indices are no longer valid or connect two entirely different vertices together. To fix this, we have to find the new index of each vertex after the removal of the vertices. We can find a function that maps the old indices to the new ones by studying what I like to call the Indices Train:

The upper row represents the original vertices, each have its own index. The middle row represents the filtered vertices, where you can see, some of vertices were removed. The last row represents our boolean filter list. If you notice, the indices of some of the vertices changed:

Blue: Became 1 instead of 2.
Orange: Became 2 instead of 4.
Green: Became 3 instead of 5.

I want you to take your time and try to figure a possible formulation for the function that maps the old indices to their new ones. The solution is simple:

 Each index is reduced by some integer n where n is the number of removed vertices before that index. For instance, Blue was reduced by 1 because only one vertex was removed before it, that is, the cyan one. Orange and Green were reduced by two because two vertices were removed before it, that is, the cyan and the violent one.

So the problem reduced to finding the number of removed vertices before each vertex. Notice that we have a boolean list that tells us exactly which vertices was removed, considering True to be 0 and False to be 1 (Contrary to the normal boolean representation), if for each element, we sum all the booleans before it, we will get exactly how many vertices was removed. For Blue, we have 0+1 = 1 as expected, for Orange, we have 0+1+0+1=2 as expected, and finally for Green, we have 0+1+0+1+0=2 as expected. We can implement this by using a loop:

We create an initially zero integer, at each iteration, we reassign it to be itself plus not boolean, the not is to implement the statement "considering True to be 0 and False to be 1". And then we append the integer to an integer list. Take your time to understand why this work.
All we have to do now is to subtract those from the old edge indices to get the new ones:

The New Edges loops over the edges, get the corresponding number of removed vertices from the Removed vertices loop, subtract it from its index and create a new edge indices from the result of the subtraction. Ending up with a new valid edge indices list. By outputting the filtered vertices and the new edges, we get the mesh that should be skined:

If we attempt to add a skin modifier now to get the skined mesh, we will be disappointed; because it will not work, the reason is explained in the following section.
Skin Root
The skin modifier requires one vertex to be a Root. A root is basically a vertex that blender uses as a reference to compute orientations for the output mesh. Upon adding a skin modifier manually, blender automatically adds the vertex at index zero as root, that's why you nearly never have to set the root unless needed. However, Animation Nodes keeps writing a new mesh to the object every execution, and since the skin modifier was already added in some previous execution, those new meshes don't have roots simply because nobody set them, this, in turn, cause the skin modifier to fail. The solution is simple, we just have to set the root to some vertex (A process that may be arbitrary if no fine tuning is required). Well, not really. You see, blender store the skin data in the data.skin_vertices data collection and as it turns out, blender doesn't allow us to create such data collection. So the only way to get this to work is by removing the skin modifier and adding it again, something that was described by zeffi in this question. Another method would be using the bpy.ops.mesh.customdata_skin_add operator which require context overwrite, something that we shouldn't really be doing in Animation Nodes. To remove the modifier and add it again, we can use the script:
#If there is a skin modifier by the name "ANSkin", remove it.
if 'ANSkin' in object.modifiers:
    mod = object.modifiers['ANSkin']
    object.modifiers.remove(mod)

#Add a skin modifier called "ANSkin".
mod = object.modifiers.new(type='SKIN', name='ANSkin')
#Edit the options of the modifier:
mod.use_x_symmetry = False

#Output the input object
outObject = object

If you are not familiar with the script node, please study this first.
We now have a working skin modifier:

One thing we can do is control the radius of each of the edges, which we can do using such script:
for v in object.data.skin_vertices[0].data:
    v.radius = radius, radius

Which when used:

Notice that we can control the radius per vertex, so one can use such script:
for v, r in zip(object.data.skin_vertices[0].data, radii):
    v.radius = r, r

Where radii is a float list with the radii, which is used as a random list, returns:

Notice that we can control the radius as two individual values in each direction, normal and cotangent to the edge. I will let you figure this out yourself.
Blend file for study and practice:

Looks great, and thank you for including the file. I've started a bounty so I can grant an extra reward.

@Drudge I added another method. We just developed this new algorithm for you.

Excellent! I've been studying up and am starting to understand it all better. Thank you!

Thumb up for a lot of work!!!

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Change a Driver based on which Scene is being Rendered
I am looking to drive a property in a material node based on the current Scene when rendering. The purpose would be to mix between two different parts of the node tree so that one Scene renders one input of a Mix node, and the other scene renders the other. The objects the material is on exist in one scene, and a group instance of the objects exists in the other scene.
The reason for using different Scenes is that part of the material is regular shaders that need to be GPU rendered, and part are OSL shaders that need to be CPU rendered. So the only difference between the scenes is that one has the device set to GPU and the other CPU.
I know that I could make copies of the objects/materials and so have a different material on the OSL version, but this gets cumbersome as i'll need to re-copy the objects or re-create the whole scene every time I change an object. This is too inefficient while still working on the project. The Group instance means that any changes I make to the models are instantly updated in the other scene, and lets me use the Group to control which models are rendered in the OSL scene at all.
Is this possible?

Can you provide a simple sample file?  Not a fan of using global bpy in driver namespace, as in answer below.. If you set up a scene property  and use it as a standard driver variable does it also fail?

@batFINGER I've tried a custom property on a scene to run a driver but that has update problems as well. But the bigger problem is finding a variable that changes during render, and that could be updated mid render as well. I'm not sure one exists.

Can you use methods from prior question rarely use AN.  Here is a simple template to set up dud render handlers. https://blender.stackexchange.com/a/62870/15543 Could see if using handlers will set nodes as desired.

@batFINGER The method for render layers from my old thread doesn't solve this problem. It switches the driver based on the layer I have selected i the UI. So it doesn't trigger when rendering. I'll look into the render handlers. Thanks!

render init handler
Hoping the render init handler will do what you desire.
I don't have GPU rendering to test, so all I've done is set the diffuse color of simple material "Material" for different scenes based on there name, and render resolution percentage which both work as expected on the scene being rendered.
import bpy

def render_init(scene):
    device = 'CPU'
    respc = 100
    if scene.name == "Scene":
        color = (1, 0, 0, 1)
        #device = 'GPU'
    else:
        color = (0, 1, 0, 1)
        respc = 25
    bpy.data.materials["Material"].node_tree.nodes['Diffuse BSDF'].inputs['Color'].default_value = color
    print("Render", scene.name, color)
    # set scene stuff
    scene.render.resolution_percentage = respc
    #scene.render.cycles.device = device
    return None

bpy.app.handlers.render_init.clear()
bpy.app.handlers.render_init.append(render_init)

other methods would be to add a custom property say "GPU" only to a scene that you wish to render on GPU and test for it, rather than checking scene name.
if scene.get("GPU"):
    device = 'GPU'

This is sort of working. I  have a scene named Scene and one named Test. And instead of color I am just changing a value to be either 0 or 1. (0 in the If, 1 in the else.) If I hit f12, it renders both Scenes as value 0. But if I render them manually by clicking the render button on their compositor node, then it renders them properly with the switch working. So that's a big help, but why isn't it working with f12 render? And could this be made to work on a render layer basis instead of Scene? If I can switch the driver and device on render layer, I don't need more scenes.

Upon further experimentation, it seems that the problem is that it considers rendering both scenes to be only 1 render. So there's no time for the render handler to update things between them.

It is possible to script drivers. Normally if you use a scripted expression as a driver, you can use any function that is defined in any script and added to driver namespace:

import bpy

def f():
    if bpy.context.scene.name == 'Scene.001':
        return 1
    else:
        return 0

bpy.app.driver_namespace['f'] = f

'Register' would need to be checked in the Text Editor also the script needs to have .py extension and Auto Run Python Scripts must be enabled for the function to exist every time the file is reloaded.
However apparently this does not work with driving material node properties because Blender's drivers seem to be broken in this area.
It would probably be possible to script an app handler that would take care of it, but at this point I would suggest to simply use a script to switch the mix nodes in all of your materials before rendering. Since this extra step takes only a few seconds it might be easier to have less complexity and you could possibly get away with only one scene as well. You could give the Mix node some specific name in every material like for example "OSL_mix"(in the n panel of the Node Editor). Then you could run this to change the values of the nodes with that name in all your materials at once:
import bpy

for m in bpy.data.materials:
    for n in m.node_tree.nodes:
        if n.name == "OSL_mix":
            n.inputs[0].default_value=1 # or 0

For your convenience you could change the render setting with the script as well by adding something like:
bpy.context.scene.cycles.device = 'CPU' # or 'GPU'
bpy.context.scene.cycles.shading_system = True # that's the OSL
bpy.context.scene.cycles.samples = 1000

Or something like that. You can just change what you want in the render settings and copy the command from the Info panel.
I would just have two scripts like that to switch between CPU-OSL and GPU rendering.
I hope that might be a convenient enough workaround.

This is working but isn't solving the whole problem because this driver doesn't update regularly, or while rendering. The driver updates the first time I change to a different scene, but doesn't when I change back. To have it update again I have to reload the file. It also doesn't change when rendering. Both scenes render with whatever value was in the driver when I hit the render button. So either it doesn't update during the render at all, or the current scene doesn't change during the render. So this is only doing it based on the current UI state.

Seems to work when I test it: https://media.giphy.com/media/WygKP5JZ5LDAETRPMV/source.gif Could you maybe edit your question and add more detail about the process you are using for rendering so we can troubleshoot this?

Drivers in Blender... I sometimes wonder what's the point - they seem not to work most of the time...

Is it updating during Render for you? There isn't any more detail to add about my render process i'm afraid. I am just hitting f12.

OK, so that's some detail. You are not rendering from command line for example. How are you switching the scenes? Manually as well?  As you can see in the GIF, it updates the location of a cube that is linked to both scenes. As it updates, rendering will be correct as well. I will try with materials.

You are right it does not work with driving material properties for some reason. That must be a bug. See the edited answer, I hope that might help.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Using DataTransfer modifier with Custom Normals in Cycles
I am trying to use DataTransfer modifier in Cycles to improve toon shading on a character. I am using Face Corner Data - Custom Normals. I am getting strange shading with dark artifacts. Part of the problem seems to be that it marks every edge on my mesh as Sharp. If I unmark these, it marks them again next time I render.
I have used it in blender internal without problems. Is there some special settings combination you need to use this tool in Cycles, or does it just not work?


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Re-mirror weights for whole character
I have a character setup with proper .L and .R ending vertex groups. I have been making weight changes to one side of the character, but now have found that I left X-mirror off for some of them. I know that I can manually mirror any given group through the vertex groups panel, but I need to re-mirror 20+ groups. Is there a way to mirror all .L groups to .R properly?

Related: http://blender.stackexchange.com/questions/16504/is-there-any-way-to-copy-the-weight-of-one-bone-over-to-anotherforgot-to-use-x

Yes, that is the method I meant. But that's manually one group at a time.


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Use all Objects in a Group as Object input (Animation Nodes)
I am using a node tree that takes an input object, and generates a new object based on data from it (see here for the exact use case).
I want to apply the effects of this node tree to more objects without having to copy the nodes for every object. I want to be able to control which objects go through it with a Group or List or something similar so I can control what's in and what's out. The output objects need to remain separate from each other. It should not have all the output meshes go into the same object.
Is there a way to input multiple objects from a Group, other otherwise make a list?

Lest say you have a list of n number of inputs objects, then your node tree will output n number of objects. So, you should create n number of empty objects using the Object Instancer Node, loop over the input objects and write the data of each iteration to one of the empty objects you created.
Lets use the node tree from the question you linked as a study case, the output object is a curve object, so we create 3D Curve typed empty objects using the Object Instancer Node, loop over the inputs objects and the empty objects, do what ever you want inside the loop and write the data into the empty object:

Notice that the main part of the node tree is almost left intact. It is particularly helpful to output the new objects, and since they are used as iterators, we can use the Use X as output option in the loop advanced node settings:

Had my output data be meshes, I would have choose mesh objects in the Object Instancer Node. You get the point.


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Equivalent Mix fac to Fresnel?
Normally we use Fresnel (either from the node or layerweight) to mix between Diffuse and Gloss shaders. This works best for normal shaders, but isn't always best for non-realistic shader setups, or multi layer materials. I am working on a shader setup that uses normal shaders mixed with fresnel, but also includes toon shaders with a flat mix fac.
I want to establish a relation between Fresnel IOR and a normal flat mix so that I can derive the flat mix from the IOR. In other words, I want to take the IOR input from my node group, do some math to it, and end up with a flat mix for my toon shaders that will be about equivalent in shininess to the IOR.
I understand that "shininess" isn't a particularly precise descriptor. Is there any particular math, or just general rules of thumb I can use, or do I just need to eyeball this?

I would just play with the settings till stuff works. No need to do fancy math for cartoons

@10Replies I am, but I'm also asking because I thought it was an interesting question, and someone else may have already experimented.

If you're looking to calculate the Fresnel factor by yourself, a commonly used approximation is this: https://en.wikipedia.org/wiki/Schlick's_approximation
This should give you a percentage of how much "gloss" there should be.


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Drive shapekey based on activating a pose?
I have a character with a rig that involves an armature with a pose library, and various shapekeys made from backed simulations. I want to make it so that when I load a specific pose, it also turns sets the influence of the associated shapekey to 1.
It seems that either I need to run a script that takes the name of the pose and shapekey and loads them, or I need a way to have it automatically activate the shape key when the pose is activated.
Are either of these options possible? Is there a better way?

You could try driving the shapekey and an action constraint from the same property or controller. Or control the action constraint's influence directly and have the influence drive the shapekey. This will require explicitly loading the pose though, you won't activate anything just freely posing the rig close to a given pose.
It is also possible to add a set of marker bones indicating the pose and then create drivers using 'Rotation Difference' variables between the marker bones an the actual bones and make it so the dirver is fully activated when the rotational difference is equal to zero. This may be vary complex to setup and tune for complex poses though, but does give the advantage of allowing free posing of the rig.


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Faster rendered viewport shading
I'm trying to preview how a specular material looks on an object when it moves, so I tried rendered viewport shading mode, but this mode is extremely slow even with a very simple object.  So slow that if I play a simple rotation animation nothing draws to the screen.  I'm running an i7 with a GeForce 730m, I feel like I should be getting better performance than this.  Am I missing something here or is it really not possible to preview an animation with materials without rendering a video?

Rendered shading is the same as a final render (mostly), so unless you have a very simple scene and a small render farm, you probably aren't going to get even near real-time (as in > 1-2fps) renders.
Some things you can do to help:

Render a small low resolution part of the viewport (e.g. with render border) See Render Border's related check boxes - How do they work?
Reduce the number of samples (Render settings > Sampling) and bounces (Render settings > Light paths)
If you still want to use the viewport (though I would recommend rendering a quick image sequence), turn down the framerate so each frame has some time to converge.


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Result Based Texture Mapping
I'm try to rig up several small moving objects, so that at the end of the video they align to form an image. Similar to this video: https://www.youtube.com/watch?v=IcG3Jc6Vw04.
See how all the cubes are jumbled, but align after the ball hits? I would like to achieve a similar effect, without having to map an image to each cube face. I'm guessing it has something to do with UV Mapping, but not sure how to do it.
Please ask if you need any clarification.
Thanks in advance! :)

Make sure all the objects have a UV map (it doesn't have to be a useful one).
If you have a large number of objects which don't a UV map, unwrap one of them (any projection will do) and then select them all (with the unwrapped one active) and press CtrlL > Transfer UV maps. Even if the objects don't have the same vertex order, this will be fine as the UV map is overwritten later.
Simulate/animate the objects and go to the last frame.
Select all the objects, add a UV project modifier and set the camera as the projection object, select the UV map, and press CtrlL> Modifiers:

This will project the UVs from the camera unto the objects. If you move the camera in textured view you can see this in real time.
Still on the last frame with all the objects selected, press AltC > Convert to mesh to apply all the modifiers (and make the UV maps stay in the state they are in).

Result (click on it for html5 version):


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Accidentally made 3D viewport take up entire screen
https://i.sstatic.net/wdPyB.jpg
I hit a button, I'm not sure which one, and everything except the 3D view window disappeared completely. I assume they're just hidden, but outside of the HOTKEY I DON'T KNOW, there's no way to get the menus back and I'm kind of freaking out right now so please, if you know a fix, can you post it?
There's NO menu bar, there's NO timeline, what you see in the screenshot is everything I can access outside of the tools and transform menus with the n and t hotkeys.

Thank god, I figured it out. All I had to do was control leftArrow or rightArrow to switch to a different workspace preset and it eventually brought me back to the preset I was on when I messed it up.

shift+ spacebar also maximise and minimise current viewport you work on


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What's wrong with this model and rig? (It became super deformed.)
I've been struggling with this bunny model and trying to rig it for animation for a while. I made the model in Rhino 5 and imported it to Blender. But when I did, it went from this:

to this:

The bunny became really deformed and it also scaled up A LOT.
Could someone kindly let me know what's wrong/direct me to proper tutorials on how to fix this? Thank you for your time!

You probably have some problems with bone weights. Did you bind the rig to the mesh yourself or did it come with it bound already? The rig or some bones also probably has transformations (scale in particular), which affect the model and cause it to scale.
If you're unfamiliar with rigging and weight painting, start with these two tutorials:
https://cgcookie.com/archive/blender-introduction-to-character-rigging/
http://www.blenderguru.com/tutorials/introduction-to-rigging/

@TLousky Hi! I did try to bind the rig to the mesh myself. Do you suppose the model is too small/bones are too large? How do I get rid of those weird "transformations"? I'm a little confused, but I will follow the tutorials you linked as well!

In your rig there's the base skeleton (which contains what's called "deform bones", the bones that should directly influence the mesh), and four bones that lie outside the mesh next to the arms and legs. These bones seem like they're meant to be used as "control bones" - bones that usually provide you with a shortcut for more complex behavior than direct deformation. However, if you don't set these bones to not deform, they will also bind your mesh if you bind with automatic weights and cause unpredictable behavior.


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Have it so animation has transparent background to overlay stuff in video editor (transparency)
I was wondering if anyone knows how to make it so the animation renders with a transparent background so in the video editor, I can overlay "Scene" and it will have a transparent background, thanks.

By default, if you add a scene to the VSE, it comes in with alpha already, so you shouldn't need to do anything else. If you are rendering the scene, you'll need to enable transparency under the render settings. Go to your render tab, find the "film" section, and enable transparency. Next time you render, the VSE will update with the transparent image. Likewise, if you turn off transparency, the VSE will update with an image without any alpha. The viewport defaults to transparent, no matter the settings in the viewport or in openGL render settings.
Once you have the scene in the VSE, you need to change the strip's color blending mode to "alpha over" - then you can put that strip over your other media and the scene will be overlaid.
First is Cycles, then BI. (Thanks Sambler)

That applies to cycles, if you are using blender render then instead of transparent under film you need to choose transparent alpha mode under shading.


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Strange white faces only visible in weight paint? Invisible when ported into UE4
As you can see below, these white faces only show in weight paint mode.
I had been getting random invisible faces whenever I imported the mesh into Unreal Engine 4, which had me stumped.
The white faces are all the faces that are invisible in UE4, I'm not sure what to do about it, short of redoing the mesh, and making a new uvmap..
Is this a bug? or am I just missing something simple? any help is appreciated, thanks.

I've figured it out?!
For whatever reason choosing to open image, and bringing in the same texture I was using and reassigning my uv's to that fixed the problem.
The white faces have dissapeared.
Note:
I did delete faces previously and make new ones, which were where the polygons had turned white. I don't understand why this whole thing happened because of that though..

Did you try to reunwrap the hole mesh after deleting (and filling again?) faces? It could be that newly filled faces weren't asigned to the old UV map

Perhaps it's a problem with your normals?
Try selecting all the faces you're having trouble with, and turning on normals in the viewport to see if they're oriented outward properly.

(Press N if the panel isn't visible)
Ctr+N will do a quick recalculation of normals toward the "outside" of your mesh.

I've tried recalculating the normals a couple times, checked them for what you've pictured above, everything looks just fine.


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Overlay two videos and match/track background
I have two video files with matching background and I like to overlay them. Both are not perfectly stationary, so either one or both need to be stabilized and matched/tracked against each other.
Could someone point me in the right direction of tutorials or keywords to search for?
I've already read up on tracking and overlays, but combining the solutions seems non-trivial.
Some involve 3D objects, some are entirely done within the video editor / node view.
Some additional info:

its actually top-down drone footage of a racetrack and I want to overlay them to compare racing lines of cars on the track
the footage is stable enough that the tracking could be done manually with keyframe animation if automatic tracking is not possible
at least scale and rotate is needed for the backgrounds to match
ideally I could choose a selected smaller area to render into a final video in a later step
being able to use the grease pencil to draw annotations on the video would be a plus

It sounds indeed like a non-trivial solution, that will require you to get proficient with motion tracking and/or compositing.
For a 3D way to do it you would need to track the footage and solve the camera.
The success of the operation would depend entirely on the kind of motion from the cameras, if there is parallax on the scene then you might be able to recreate 3D info. If you track features for which you know the scale in the real world, then use it to set the scale in the 3D reconstruction.
You could then to re-project the image into some geometry, so that you have a reconstruction of the 3d space as fixed points, and a image projected from each of the positions on the camera at a given frame, the UVproject modifier will allow you to use the camera as a projector or you can use a lamp that is parented to the camera to project the image as texture.
You would need to do the same for the other image and manually reposition the camera so that the projected images coincide with those of the other camera.
A non-3D would be to create two un-distorted and stabilized images out of the video. Those new pieces of video can be overlaid using difference mode in a mixRGB node for clarity. One of the videos would need then to be rotated, scaled and possibly distorted so that some the features of the track correspond to those in the other image. Note that the difference in perspective from both images might prevent you from getting a perfect match. You won't be able to invent what the camera did not see.


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Can I add the output of the VSE as input to the node diagram?
I know how to add the output of node composition to the VSE (add 'Scene'), but can I do the oposite?
I want to post-process my video sequence with a filter only available as a node (Stabilize) without pre-rendering it to a file first, because it would deminish quality and waste hard drive space and processing time. Can this be done? Or is the order (3D Scene -> Node composition -> VSE) fixed?

Possible duplicate of http://blender.stackexchange.com/questions/3779/how-can-i-use-the-compositor-on-the-result-of-the-sequencer. But only very short answer there.

I found a working add-on that allows you to modify the strips using the Compositor, it's called Edit Strip With Compositor.
Note: There's another add-on mentioned in this thread called VSE to Compositor, but it doesn't work for Blender 2.76b.
So, let's get to it.
In order to install and enable it, follow these steps:

Firstly, download the latest version (it's the version 0.14 for Nov
20, 2015).
Next we need to extract the Python script from the archive.
Now, you can either install the script from the User Preferences or if you want to make it system-wide, you can copy it to the Blender's add-ons folder (in my system it's /usr/share/blender/2.76/scripts/addons). Note that this might require some administrative privileges.
Then you need to go to the User Preferences in Blender and activate the add-on.
If you want to enable it by default (on Blender's startup), don't forget to click the Save User Settings button.

After enabling it, you can start using the compositing functionality for the VSE. Here's a demo of it; however, he uses the other add-on mentioned above in the note, but they're not that different.
To apply the effects from the Compositor to the VSE strip, you need to follow these steps:

Select a video strip first (yes, unfortunately, you cannot apply the effects to the effects strips itself, but you can apply other effects on top of it).
Press N on your keyboard to open the Properties panel.
Scroll down in the Properties panel until you see the Edit strip with Compositor section.
Click the Set master scene button.
Check the Show options checkbox.
In the Compositing, choose the Compositing option from the drop-down list.
In the Editing Screen, choose the Video Editing option.
Optionally, you can enable the Add Viewer option.
Click the Create Comp from strip button on top of the section.
Click the Edit Composition button.
Now, this should look familiar. It should get you to the Blender's Compositor. Let's add the Blur effect. Open the Add menu by pressing Shift+A and select Filter → Blur from there.
Drag the Blur node over the connection path and once it becomes white, make a single click.
Select the options you like.

It should look something like this (except for the Backdrop which I have disabled):

Switch back to the Video Editor layout and voilà! The strip will be modified according to the Blender's node-based Compositing.
In order to animate the effects, you need to switch back to the Compositor and utilize the keyframing from there.

Original source


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Image bleed when using Import Image as Plane
I'm working on an project where I need to import some graphics that I created. I'm able to import them fine using the Import Images as Planes plugin.
They look totally fine when in the Material viewport shading type:

However, as soon as I go to render it out, I get these strange speckles along the sides and top:

I'm using Blender 2.76, hash 477078b and from what I can tell it's the image bleeding over the edge of the plane to the other side, but I have no idea how to fix that.
Does anyone know what's causing this and how I could fix it?

This happened to me in Illustrator CS6. When you export the image make sure you check "Use Artboards"; otherwise, it will crop it down to fit around your image and give you those lines.

I believe you to be right as for the cause of the problem. I can see two easy ways to solve it:

Scale the geometry down in the UV Image Editor and live a happy life ever after.
If you actually need to presicely fit the plane to the image, add a blank (as in zero-alpha) border around your image in your favourite image editor (1px should do it.)

Sorry if this is gibberish


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Anti-aliasing options in the compositor (for Cycles)
Blender Internal offers Anti Aliasing as part of its rendering. Cycles does not as it is sample based. Some ID masks or various passes can be badly aliased. What options are there to do anti aliasing in the compositor? I'm looking for node groups, but would also accept scripts or even outside programs.

What you are looking for to do correct compositor anti-aliasing is Full-AA-sampling. Some compositor nodes allow you to check anti-aliasing, but when you are compositing masks you will get border errors.

related: http://blender.stackexchange.com/questions/28917/accurate-indexob-and-indexma-passes


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Make Cycles materials transparent but present in BI
I am using a multi-scene setup to render out some passes in Blender Internal for anti-aliasing purposes. I have a primary scene with Cycles materials, and a secondary Blender Internal scene. The Cycles materials do not work in BI of course, and instead come up transparent.
However, some materials behave differently than others. I have Solid and Edge enabled in the BI render layer, as my goal is to get Normal pass and edge lines. For some materials, it renders out the Edge and has the normal pass, while otherwise only having alpha. For others, it is only alpha and the objects are missing entirely. I want only the first behavior.
When I have the second behavior, if I remove the material, then I get the Edge and Normal Pass, but also the regular Solid render instead of transparency. Using a material override of a material with the first behavior does not help.
In the material preview, materials with the first behavior show a sphere. For the second, it shows only their shadow.
What causes this different behavior?

I think you need to upload some test blend with example, with the setup. I am not sure if I got it right. Also you don't probably have to use BI at all and make your render layers in Cycles with materials - like a normal colors material etc.

I'll see if I can get a file. The problem is this issue is really inconsistent, and I don't want to put out my current project. Will try to reproduce it in a fresh file.

Some related questions: http://blender.stackexchange.com/q/6446/599, http://blender.stackexchange.com/q/562/599


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Get driver values from a text file
I want to make something like a config file for my scenes. This would be a list of different driven properties that could all be changed from one central location, with the ability to load different versions of the text file. For example, if I had a driver controlling a thickness value on a freestyle line set, or a specific material node, I'd want to be able to control it from the text file.
The point of this would be to set global values, and then have lots of different driven values be affected. For example, if I had lots of Distance from Camera modifiers in Freestyle that were all some base value, then modified by the value from my text file, so that I could alter them all globally.
Is this possible?

Definitely possible.  I'd go about it this way, use custom scene properties as the base properties (variables)  for your drivers.  Make an operator that sets these properties and leverage off the presets system to save different combinations to file.


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Vector math to get Curve object silhouette
If you color ramp the Facing output of a Layer Weight node, you can make a mask of faces at glancing angles. This can be used as a material based silhouette mask for effects, or directly as line art.
Here is a curve beveled into a cylinder showing the effect working pretty nicely.

However, the effect doesn't work so well on larger faces, such as the sides of a cube, or down the length of this cylinder. In those cases, it shades the whole surface because it is all the same normal facing. I am trying to find a way around this problem.

I learned from this question that it is possible to use UVs and vector math to get a curve's direction. It seems it should be possible then to either use a similar method to get the silhouette of the curve, or use it to mask out of the Layerweight along the curve, or something along those lines. But I'm not strong enough on my vector math to figure out what needs to be done to make this work.
Anyone tried something like this before, or know what to do? Of course, it will only work on curve objects.

have you tried this solutions? https://blender.stackexchange.com/questions/562/how-to-get-silhouette-with-contour-rendering-in-cycles

@MCunha I am familiar with all the methods in that answer, but the goal here is not to get any form of contour outlining. I'm specifically trying to do it with vector math so that it can be done in the material.

The solution is to calculate the crossproduct of the incoming and curve direction vectors. The absolute of the dotproduct of that and the normal is the facing which you can connect up to your color ramp.

This is the right sort of thing. It seems we've created an effect similar to color ramping layer weight, but via a different method. So this answer is correct, but it looks like I may not be able to use it for the artistic effect I wanted.

To clarify, what I wanted to do artistically was to remove the area down the middle when viewed from any angle (don't care what the end caps do though)

First of all yes i know this answer is not a shader solution.
Neither do i know how deeply you know blender.
So I was puzzling for a while, as i gave a solution for the linked article as well.
Though then i realized maybe you just want to have such an effect for some production goal. And how to get there isn't that important, maybe you just want to have outliner effect on technical drawings for example. As that's a very common usage of the effect you want.
If something like that is indeed the case be aware that there is another way to achieve contour lines, its possible to create it using the most basic freestyle line shown below :
(And if you would like to have a little bit more detail then just add silhouette.)
(and if you want to hide any feature of shape then make it emmision as i described in the article you linked)

Thank you, but as I have said in other comments, I am specifically trying to figure this out in the context of vector math on curves. It matters for the production goal. Freestyle is very limited and can't be accessed within the material.

Ok i understand, i'll puzzle some more then

Yeah, you want send the View Vector from a Camera Data node into the Normal input on your shaders.

I added Subsurf to soften it a bit.  Object masks often do better if they don't cut off suddenly, so that was the thought there.  You can tweak that if you want.

You may decide you don't need Glossy.
I thought it looked decent, but it might not be needed for your purposes.
Hope that's what you were going for.  Lemme know what'cha think.

I'm afraid I don't understand what this is doing at all, or what it has to do with the question.

You're trying to make a black & white mask to outline objects for use in something like Photoshop or Gimp, right?

No, I'm trying to make a mask down the length of a curve object

To only get light on the curved surface, and nothing on the flat side?

No, it isn't to do with shading at all. This is to make a mask based off angle of normals, minus some areas based on curve direction.


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how can I accurately simulate ballistic physics?
I am trying to find out how to make a cannon or gun that works with the physics simulation. but I have two problems.

I'm not sure how to suddenly apply force behind an object,then remove it.
I can't stop the projectile from wedging into the barrel and bouncing around trying to escape.(the alternative is to make is smaller, but it still "bleeds" through the mesh)

how can I use the ridged physics engine to create a ballistic simulation( mortar, gun,etc)?

gandalf3 found the real solution (just below my user icon), I left the bad one here for fun. have a magical day this video + some imagination should do the trick. the video shows one object being animated into another one which freely moves as a rigid body. copy this but have the first object(the animated one) be an invisible object that is overlayed with an explosion. make the second object your bullet. skip to 1:15 to see the effect im talking about. also keep in mind that along with changing the speed of the pushing object, you can change the mass of either object to alter the speed of the

See http://blender.stackexchange.com/q/5100/599 and http://blender.stackexchange.com/q/8483/599 for animation based initial velocity/activation.

does this both stop funky collision detection and allow the force to be added at any time during the sim or only at the beginning?

@user16973 Hm.. Unfortunately my comment was deleted somehow, but I linked some posts about both. Here are the links again: post 1, post 2, post 3, post 4.

If those don't answer your question, then feel free to either leave a comment on one of the answers, or post another question if you feel the other questions aren't the asking same question you are. Also try to keep your questions to one question per post :)


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rendered video is different from preview
I've been going through a video and trying to extract parts from it,rendering each part as segments. partly through I realized that the resulting files had a slightly different part than was being played in the previews. how can I make it so that the video I see and hear in the preview is the same video that gets written to the file?

probably you didn't  enable AVsync?

Have you tried rendering in OpenGL?.  That's accessed at top left of 3D window in the "Render" drop-down.  Select  "OpenGL Render Animation".  It's a WYSIWYG render. (most times)

It’s the codec. Render to still frames then cut.

I'm having the same issue. Turns out that the Proxy render size under View Settings, Really destroys the accuracy of the video in preview.
Notice how the 'Text' and 'Character' deviates from its original location.

Images and Videos are not affected, But  Text, Any sort of animation is affected.
The solution I found for myself is to fix all the glitches manually in full render settings.
Edit:
Turn on AV Sync. You will find it under Timeline-> Playback -> AV Sync (check mark).


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Mesh visible on object mode, invisible in edit mode
I'm rendering a staff with a transparent diamond prism, and everything was working fine until I noticed, while animating, that the crystal was suddenly displaying its texture as though it were opaque.

When I examined the object in edit mode, I noticed that it was invisible. Attempting to select all vertices with "a" and using "alt+h" to see if they were hidden in edit mode did not solve the problem

I checked the texture the crystal is bound to just to make sure that it was transparent.

What would cause the object to be invisible in edit mode? And why wouldn't it display with its proper opacity?
Here's the blend file: http://www.pasteall.org/blend/30844
imgur album: https://i.sstatic.net/9CaaV.png


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text from updating file
I'm learning to use blender in order to get this result:
when I push a button on pygame I'll have a solid, like a stone, appearing from the ground. on this "stone" I would have written a text from a file that changes every time I use this function. I would only ask if it's possible with blender to have this result, or it's better to give up and think something more easy to do?
thanks for the help.

Do you want the text to be a texture on the stone or can it be a separate text object?

Is this an animation? Or are you using the BGE?

@maddin45 - I would have a texture on the stone.

@gandalf3 - I don't know what is BGE but I would have the stone (or a box) come out the floor and some text printed on it (if possible!!)

It's not clear to me how this is related to pygame so I focus on this part of your question:

I would only ask if it's possible with blender to have this result

Yes, you could create an action with two keyframes (start and end position of z coordinate of your cube).
At the right side you see the action "CubeAction" in the Dope Sheet (set to Action Editor)
At the bottom a Keyboard Sensor which is active when Space is pressed and an Action Controller which plays the animation stored in the action.

To dynamically create the text object one idea would be to copy it in the text-editor and use:
bpy.ops.text.to_3d_object(split_lines=True)

This function is probably not available while the game engine is running
For how to load a text into the editor see: How to programmatically load a python script in Text Editor and launch it
How to port this to pygame isn't on topic here.

the suggestion for blender is just what I need, thanks. relating to pygame, I still have to verify but I think to use a button to launch my blender animation.


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How to create a material that is part solid, part transparent wireframe?
For a 3D rendering of an organ, I would like to make part of it a transparent wireframe so the contents become visible (similar to this image, only I would like to have a much smaller area as the transparent wireframe). Could anyone point me to a tutorial, our explain me a bit how to approach this? Thanks!

I asked something similar a while back: http://blender.stackexchange.com/questions/7954/transitioning-the-overlap-of-multiple-objects

This comment actually answered my question, thanks!

Thanks to ajwood, solution here: http://blender.stackexchange.com/questions/7954/transitioning-the-overlap-of-multiple-objects

Nice! I'd love to see the image you made, if you can share it!

In Blender Internal render engine, you can use Freestyle. To enable freestyle - Go to the render panel and click freestyle -
Then go to edit mode, select the edges that you want to render and press "Crtl+E"
and click "mark freestyle edge".

Then go to "Render Layers", click on the Line set that should be automaticly created and click only on "edge mark"

Then on the tab "freestyle line style", you have options for the lines.

Then you can click on render.


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How to replicate this effect (Parts of material more reflective than others)
Long story short, I've modeled Toothless from How To Train Your Dragon in Blender, and I'm now trying to replicate the effect that the runes/scales it has. I've been using blender for +2 years now but it's always been the modelling side of things and I want to branch out to textures.
I'd like to use the cycles render engine to achieve the following effect:

Note that the stones/scales/runes are raised from the surface in a way bump/normal mapping could not achieve, and that they're more reflective and glossier.
But having never done any texture work, I've no idea of a good way of going about it. I've tried various methods, each of which did nothing like what I wanted.
Currently, the model is just that, with no runes or anything physically on it. My original plan had been to make three textures;
        1) for the visual,
        2) for the displacement - which would then be baked on - and
        3) which would define the areas to be more reflective etc...
but now I've actually tried doing it, it seems to be a tad more complex than that (as with most things blender, hehehe). I've tried a google search, but nothing relevant comes up.
I'm not asking for someone to outright do this for me because I want to learn it for myself, but any help would be greatly appreciated, be it a guise, a link to a relevent tutorial, or even just a helpful hint.
Thanks so much to anybody who can help me out here!
(As a footnote, I've already done the model and manage to get the materials sorted for the eyes and surrounding area. Once it's finished, I'm putting it in the public domain for anyone to use, and I'll happily say you helped ;) )

The following is a way to handle displacement in a way that offers a lot of control and works very well for baking various types of maps including normals, height and ambient occlusion.
To start with, add a multi-res modifier to your model as shown in the following image.
Now make sure you are back in Object mode and increase the number of subdivisions for the modifier.

Now that the mesh is ready for geometry displacement you can add a Displace modifier as shown here.
Now once you've added displacement it could look something like the following
(For people that don't know this already, if you right-click on an image here on StackExchange, then choose 'View Image' you will be able to see the larger version so detail is more clear.)

For the nodes, I've used the same basic setup as username:GiantCowFilms with a brightness/contrast node added in to adjust the mix between Shiny and Diffuse.
The same image is being used for the Material and the Displace Modifier.

This is more like what I was looking for! This allows me to set the features as physical things, AND make them more reflective. Thanks especially for the images as well, they really really helped!

Here is how you can create you desired effect:

The set up uses two textures, one for the displacement and the other to control reflectivity.
Notes

You can use an image texture instead of the noise texture.
You can add a color ramp between the texture and the mix shader node
to add more control to the effect.

Edit:
Here is how you can add a uv map to the texture:

Make sure that you get the name of the uv map perfect, otherwise it will not work.

Excellent! I'll give this a try ASAP. I take it when I select Image Texture it will let me specify the UV map to use?

Yes, see the edit

user2926289, there is now a UVmap node available for the latest builds.  This node does not give us grief about spelling since it has a selection of all available UV's.

Good to know. I don't use test build features in answers(unless that is very relevant to the question) to eliminate confusion.


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Blender only renders black frames
I've been working on a project that contains a building with some textures and materials and an animation. When finished I wanted to render the scene. I rendered the animation using jpeg as output. But when I went to the output folder all the frames created turned out to be pitch black.
Even as I try to render a single image I get this window
using cycles render I get this result

Also the rendering time is extremely short and as my scene is quite complicated I think that it doesn't consider my scene at all.
Can someone help me render my scene?

I think a .blend file, which you can upload here would help us understand your issue. Add it to your post as an edit. Thanks

Figured it out. The composition checkbox and the sequencer check box should not be checked. You can find these checkboxes in the properties panel under render under post processing.

Make sure these aren't checked and it should work.

This isn't the best workflow. It's good to unckeck them just in testing purposes but once it's clear one of them causing that it's better to investigate sequencer's clips and compositor's nodes. Sequencer and compositor are too good features to not use them at all.

Thanks this was it!


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Is it possible to slide an edge beyond the two vertices its attached to?

Hey guys!
I got a simple, hollow circle mesh that I'd like to gradually fill by using edge slide. Meaning that I want to be able to slide the edge from the top to the bottom of the circle
The only problem is that I can only slide an edge in the space between the two vertices the edge is in between...or maye the vertices won't go past the other vertices, thus preventing the edge from sliding further. I'd like to slide beyond those vertices. Does anyone here know if it's possible to do that?
I'm very new to this, but I'm willing to learn and I would appreciate any helpful comments. :)

Do you require that this be done using a mesh object? Could it be a curve object instead? If you tell us what the desired end result is, we can think outside the box a little more when brainstorming solutions. Depending on what you want to do there may be a suitable solution of a totally different nature.

I don't understand this question either.

Sliding beyond edge limits is possible, if this is the question, then it's a duplicate of Vertex slide past edge limit?

Not as far as I know. If this is for an animation, have a look at booleans: https://www.blender.org/manual/modifiers/generate/booleans.html
They are implemented as a modifier, so you could have a hidden (hide it from the outliner by disabling it's render) circle (or rather a cylinder) acting as a "stencil" and then a plane that gradually grows in width. This plane would have the modifier set as "intersect" on it. This would make the plane only show in places that are inside the cylinder, thus creating an effect of the plane filling the circle.

If your effect need discrete steps, there is a way to do what you need, but not sliding edges: it works building the circle in horizontal stripes, and using a "build" modifier. It could be not perfect, but could fit your need somehow, so I try anyway:

here are some steps (at frames 1,11,41,81) :

Just to give you another idea...

@user277143's suggestion of using booleans would work.
Depending on you needs you could simply leave the circle whole. Then use a masking object, and just animate it moving out of the way.
You just need to have some understanding of 'Render Layers'.
The workflow would be: set up your scene normally, but reserve 2 working layers. One layer for the object being masked, and another layer for the mask itself. Setup 2 render layers, one for everything, and one for the masked objects. Then composite the layers together for final output.
In the example, layer 9 is the object being masked, a cylinder. Layer 19 is used for the mask, in this case, just a plane.
The plane is moved out of the way, to reveal the cylinder in the rest of the scene.

There are 2 Render Layers, 'MaskedObjects' which renders the scene with the mask in effect. And 'AllOtherObjects' which renders everything normally except the mask and masked objects.
The result of compositing them together:

Just another way of doing things. Here is the file above:


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How can I make multiple meshes into a single hollow mesh?
I have a character made up of multiple meshes, namely a body mesh and two eyeball meshes. I am interested in exporting only the visible surface of the character.
When I export to STL or PLY, the interior vertices remain. In other words, the parts of the eyeballs that are inside the body are included in the export. (Labelled 1 in the diagram below.)
An additional complication is that the body mesh has an interior "mouth" component. Again, vertices that are not visible from the outside are included in the export. (Labelled 2 in the diagram below.)
How can I modify the mesh so that only the visible "surface" vertices are exported?

Gamera / Chinchilla mesh from Big Buck Bunny
(C) Copyright 2008, Blender Foundation / www.bigbuckbunny.org
Shared under CC-BY 3.0

For separate meshes, you should first of all join them in a single object (ctrlJ)
Then, if in that object you have separate "islands" of faces (like eyeballs and body) you can either:

join them manually, adding new geometry, or joining existing
make (eg) eyeballs intersect body by enlarging or reducing any of them, and then use a boolean modifier with "union" to get a single, "manifold" mesh (check very well normals before using booleans, and to not have negative scale, since that would invert normals effect in the boolean). Needs some practice with simpler object.
to remove "interior geometry" I have no other solution then removing it manually, eventually closing open surfaces left inside (there could be some, since the model was thought for a usage (render, animation) for which this was not a problem).
anyway, since you're creating stl, I guess you are going to print the object, so, you can surely have some help before exporting by using the "3d print toolbox" addon (included, but not enabled by default) to find and correct problematic shapes. And after export, the print program tipically have some "correction" tool to fix minor problems.

It actually prints fine without any changes. But I'm using a Kinect to register the printed object, and I'm trying to remove the interior points (cause they're "noise" for registration purposes). Sounds like the only solution is returning the modelling phase - not ideal, but it is what it is!


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blender reports non existant tris
I am using Blender 2.76. When I go to the default scene with
the cube I get what seems to be an error. Up top Blender lists
the cube as having 12 tris. Is this a bug or do I have something
wrong with the Linux Mint 17 version of Blender?

Not a bug. Every quad has two tris.

This is not a bug, it's a feature! :-D
Joke aside, blender is letting you know how many triangles you would have had you converted all your polygons to triangles.
The tri-count is an important number for lots of purposes, including game asset creation (where you always try to maintain the lowest polycount possible), 3D printing and other areas,
Several file formats support only triangles (STL for instance), and convert everything to tris implicitly (while others, like Collada, support quads too but convert to tris by default). So this gives you a preview of the number of tris you will have after converting.


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Workflow Question: How to get from a 3D scan to Aurasma Augmented Reality
I'm trying to get a model taken from 3D scan using the Autodesk 123D Catch app into Aurasma. According to their FAQ, this needs to be exported via OpenCOLLADA and that's why I've installed Blender for the first time. I've downloaded my model as an .stl and also a .obj and have managed to open it up in Blender and that's as far as I've got.
According to the Aurasma instructions I need to, "Upload the following files to Aurasma Studio as a .TAR file (Windows use 7zip and on Mac use GUItar).
• DAE file created in 3D using Collada exporter
• PNG’s for textures
• PNG thumbnail named ‘thumbnail’ with .PNG extension
I have managed to export the model as a DAE file but it ends up being over 100mb because of the complexity of the mesh (I'm guessing). I've tried using Decimate to reduce the model complexity but this seems to cause issues with the textures no longer matching the model's topography.
I have no idea what I'm doing here or how to go about getting the texture PNGs etc, so if someone could talk me through step by step I'd be really grateful. Bear in mind I've never used Blender or anything comparable!
Many thanks

Decimate modifier doesn't take in account UV maps.
With the collapse option enabled it:

...merge (s) vertices together progressively, taking the shape of the mesh into account

While mergin vertex, it likely happens that the UV mess up. You should create a new UV map for the decimated object and stick the original texture to it.

Start from duplicate (Shift+D) your mesh. Rename the source object
"Highpoly"    and the duplicated one "Lowpoly" (keep them in place,
overlayed)
Add and apply a Decimate modifier with the wanted settings on the Lowpoly object
The UVmap of the Lowpoly has now been destroyed in the decimation, you must re-unwrap your model.
Bake the original texture from the Highpoly to the Lowpoly as shown for example in this video (the only difference is that you should bake "textures" instead of "normals")

You need to add more details on how to bake the texture, otherwise the OP, probably, won't be able to do it.

Thank you so much for this. I'll give it a go but it does sound quite convoluted for someone not yet familiar with all the Blender jargon. A quick explanation of how to "bake the original texture" would be much appreciated.

You are both completely right. I didn't fully developed the answer intentionally because I thought it would come out pointlessly long. I would like to give advice about the path to follow rather than a step by step instructions. Even "re-Unwrap" its not an easy task,  so it would also need a proper explanation @someonewithpc, and maybe, for a beginner, other steps too. I think it would not be a good idea to answer here all the question that may come up: there are lot of resources outside that cand do it better. I'll link them asap.

Let me know what you think, because I plan to write down a tutorial about the topic anyway (sooner or later) but I thought this was not its place to be.

@Carlo I guess you do have a point


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Horizontal particle gravity
I am trying to animate a collision between an asteroid and a planet. I have a particle emitter at the point where the asteroid hits the planet which emits particles, however they unrealistically fall down the Z axis.
Ideally I would like them to blow out from the planet then curve back and land on the planets surface due to the planets gravity. I would also like a smoke simulation to spread out from the area in a similar way, so a way that would do both would be great.
The closest I have got so far is animating force fields however they look very unrealistic.
My current situation:

I think in blender objects have not their own gravity, so one way to do what you wish could be to setup the "collision" scenario in a way that the planet has the blender origin at its own center, and the grid Z axis oriented towards the surface collision point. In that way the "local" gravity will work. Maybe you can use another scene for that "local impact", but "observe" it from the expected point in "universe", then mix them together compositing. You can also use game engine recording option to get the "impact" animation recorded, and then use it in the "universe" scenario... just an idea.

Quick anwer, you can reorient gravity by changing the world setting on the scene tab.
From

to

However force fields can provide a more realistic collision at a planetary scale.
For example, here is a direct impact

and a glancing impact

To do something similar to this, do the following in Blender 2.76:

Create a new blend file.
Delete the cube.
Add a sphere for the planet.
Set the gravity in the scene to 0 for all axes.

Rename the sphere to 'Planet'. This is so we can refer to it easier later.
Set the physics for 'Planet'

On the physics tab select 'Force Field', 'Collision', and 'Rigid Body'. This will add several panels.
On the 'Rigid Body' panel, unselect 'Dynamic'. This will prevent the planet from moving due to the simulation.
On the 'Force Fields' panel set the force to a negative value. This will cause other rigid body object and particles to move towards 'Planet'. Use a value of -50 for this example.

Add another sphere. This will be the meteor which crashes in the planet. Rename this sphere 'Meteor'. You might also want to adjust the camera to keep both objects in view.
On the physics tab for 'Meteor', select rigid body. At this point, hitting play on the timeline (or alt-A) 'Meteor' should be pulled toward 'Planet' and stop when it hits the surface.

The final step is to add particles for the explosion on impact.
When running the animation note when the 'Meteor' hits 'Planet'. In this example it occurred at frame 27.
On the particle tab, add a particle system to meteor.

In the emission panel, Set the 'Lifetime' to a large number to make sure the particles persist through the animation. In this example, use 500.
Set the particle 'Start' and 'End' to the frame of the impact. In this example the value is 27. Adjustment may be required for the specifics of a simulation.
In the Velocity panel, set the 'Normal' velocity to a value large enough to overcome the velocity of the impact. In this example, a value of 15 was enough.
On the physics panel, select 'Die on hit'. This will cause the particles to disappear when they hit 'Planet'.

Play the animation using the play button or alt-A, and the result should include a shower of debris after the impact.

The blend file for the direct collision animation above is available at


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Constrain elbow rotation
I have motion capture data for arm joints as 3 empties: Shoulder, Elbow and Wrist. The motion capture data only includes 3D location with no rotation information.
I wish to place bones between the points so I can use the motion capture data to animate my model. I have used Copy Location and Stretch To constraints which place the bones correctly, however, I'll often find the elbow bending backwards or sideways depending on the position of the empties.

I would like the elbow to behave in a more "elbow-like" way and have the bones automatically rotate to pass through the empties. Is this possible? How would I go about doing it?

In order to reach the empties while constraining the rotation of the elbow to a single axis, you can use a locked track constraint on the upper arm bone, like so:

I've enabled the display of bone axes, so we can see what's happening more easily.  When the upper arm's rotation is unconstrained, as in the middle armature, the lower arm cannot reach the "wrist" target without bending freely (rather than constrained to a single axis.)  But when we rotate the upper arm to point its Z axis at the wrist, via a locked track constraint, then the lower arm will only ever bend in a single axis to reach the wrist.  Here, lower arm is still using a damped track constraint to reach wrist, but if I wanted, I could just as easily use a locked track (lock X, track Y) to reach wrist.
I'm using damped track constraints instead of your stretch-to constraints, which I would recommend, but there isn't any difference; as long as the markers remain a proper distance from each other, a stretch-to acts exactly the same as a damped track.  (Copy location is also unnecessary, provided that the bones have a proper hierarchy; they'll get their location from their parents' tails being at the marker locations.)

This works perfectly! It's also a really great example of how the locked track constraint works.


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Best way to change a value between render layers?
I have a setup where I am re-rendering the same geometry on several different layers. I want to change a property in the geometry's material before each layer runs (probably via a driver). The goal is to render out several different passes and have them all in the compositor together.
(I am aware this is possible with Scenes and different materials, but it is a ton of work to set that up when working with assets that will be linked into a bunch of different files. The simpler method seems to be to put several material setups in the same group, then mix between different outputs for each layer.)
For Renderlayer 1, the value is 0. For layer 2, the value is 1. etc.
I can manually do this by clicking the Render button on the Render Layer node in the compositor, then manually changing the material value, then manually rendering the next layer. But I need to automate it so that I can leave it running for long renders.
It seems it should be possible to solve this problem in a couple of different ways, but it depends on the details of how the render command works.
I could make a script that sets the property to 0, starts the render of layer 1, then when that finishes sets it to 1, starts layer 2, etc. For that, I need to know how I can have a script tell when a layer finishes rendering?
Or, I could have it start the value at 0, then detect when a layer starts rendering, and change it then. Either way, it needs to be able to have a script get info about when a layer starts or finishes.
Can anyone shed some light on how this can be done, or if there's a better way to set this up?

There is an addon, Oscurart Tools that has material overrides among its features. It might be useful for what you intend to do (and even if it's not, the python code may give you some hints about where to look at).
https://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/3D_interaction/Oscurart_Tools

@Gez I can't do exactly what I'm trying to do here with Oscurart, but certainly some other interesting features!

I don't think there is any way to know the name of the render layer currently being rendered, which means you can't use a driver or app.handler to calculate a property that varies by render layer.
We can however, render one layer at a time, this allows us to control which layer is being rendered and to alter properties before starting to render a layer.
As an example, we can set a text object to the layer name.
import bpy

for l in bpy.context.scene.render.layers:
    bpy.data.objects['Text'].data.body = l.name
    bpy.ops.render.render(layer=l.name)

Note that rendering a single layer doesn't work when rendering an animation, which means you would need another loop to render multiple frames.

Thanks, I'll give it a try. I'm not concerned with animation at the moment. Although if I was, i'd want to render the given frame for each layer, composite, save output, then render the next frame.

Can you expand a bit more about how to use Render One Layer at a time? I'm guessing I need to do something like Set driver value for layer 1, then render layer 1, then set for layer 2, etc. But I'm not clear on the proper way to do that still.

Calling bpy.ops.render.render() will render the scene. If you pass it the parameter layer='xx' then it will only render the renderlayer named "xx". So you can  make changes specific to a layer and then render that one layer, no drivers used.

That did it, thanks! Although I notice that when I render this way, I don't see the progress or tiles or anything. Would like to get that back somehow. But that's a matter for its own Question.

@Drudge have a look at this answer and this answer


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Is this actually a dependency cycle?
I am using an armature with the following setup:
-A bone chain that is attached to a Curve with SplineIK constraint
-A free-floating bone that a curve point is attached to with the Hook Modifier.
My console is getting spammed with Dependency Cycle Detected errors. It says the curve is dependent on the Armature through the hook modifier, and the armature depends on the curve through the spline IK.
At the object level, it does look like a dependency cycle. But none of the bones in the splineIK chain are effected by the hook bone, so on the bone level there doesn't seem to be any dependency cycle.
However, I do seem to get behavior where if I move my Hook bone around, the splineIK chain moves with it. But when I reset the hook bone with alt+G, the splineIK chain does not update until I start another transform. This is a typical symptom of a dependency cycle.
What can I do about this? Do I have to have my hook bone be a separate armature?

If you have a single hook bone, what happens when you move it to a new armature?

This is one of the key reasons for the dependency graph rewrite, the old blender dependency graph treats an armature as a single node in the graph, dependent on everything any of the bones are dependent on.
The new depsgraph, which is still a bit of a work in progress, should fix this.
It can be enabled by passing --enable-new-depsgraph when launching blender, and may help.
For more info see:
https://code.blender.org/2015/02/blender-dependency-graph-branch-for-users/
https://code.blender.org/2015/03/more-dependency-graph-tricks/
A separate armature would fix this for now as well.

How do I pass a command when launching blender?

@Drudge if you are on windows, create a shortcut to blender.exe, then right click and open the properties for that shortcut. and add --enable-new-depsgraph to the end of the target field, it should look something like: "C:\path to my blender\blender.exe" --enable-new-depsgraph

Yep that works!


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Vary particle hair settings within same system?
Is it possible to have a particle hair system that has multiple different settings combinations in it? For example, have different settings for hair thickness, or child shape and clump?
Alternatively, if you have multiple particle hair systems with different settings, can you get their dynamics to interact together as if they were the same system?

You can drive it with a texture

This question is one of the top hits for "particle hair" can someone expand on VRM's "You can drive it with a texture" comment?


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Fill a mesh with particle hair
I want to take a low poly hair mesh and fill it with particle hair on the inside. This can technically be done by emitting the hair from the faces of the mesh (and flipping normals so they face the correct way) but then the hair won't be in the proper direction. I want the hair to originate from a point, and then taper to the tip of mesh spikes.
The particle hair also needs to  move with the mesh, which will be rigged.
Any ideas on how this could be done?

Does selecting emit from > volume do what you need?

I'm afraid not. That makes the strands emit from inside the mesh instead of from its faces, but it doesn't help with direction.


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"Group" animated objects
I have some objects which are animated, some by keying values (mostly shape keys) and some keying location and scale. The end result is a flower growing:

I would like to easily be able to duplicate the flower and modify it as a whole without having to select every part, and perhaps use it in a particle system but currently most of the objects are separate (the end of the flower is all parented to an empty). I have tried to parent the whole object to something but the animation starts to do interesting things...

Ideally I would like something like groups in Photoshop where the whole object can be duplicated and manipulated as a whole but you can still modify the components. If I have to somehow "bake" the animation first this is not much of a problem though.

Can't you join the parts, instead of parenting? They will be still isolated from the others but still selectable (start with 1 vertex and then L key)?


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Freestyle with multiple objects
I have several objects that intersect each other:

I would like to draw lines on the silhouette and key details with Freestyle, however Blender does detect intersections between objects and gives a very strange result:

What I'm trying to make is something like this:

Note: This is just an example, what I'm trying to do has about 10 highly detailed objects which intersect each other, so manually combining them is not possible.
Is it possible to make Freestyle detect edges at face intersections? If not, is there a simple way of combining the objects to create a single object with the outer faces of all the objects?

Short answer, no, Freestyle doesn't currently support detecting face intersections so what you want to achieve is basically impossible to do at this time, as far as I know.
There has to actually exist an edge there so Blender can detect the intersection and place a Freestyle stroke where it belongs.
Ideally you would build your model accordingly, so that there would be no intersections and your model is correctly shaped with no "inside" faces.
Otherwise you may try to use boolean operations through the Boolean Modifier and automatically intersect your objects and let Blender create said edges.
Have in mind that boolean operations have limitations, and will only work on closed, manifold meshes with no duplicate vertex or edges, consistent normals and non coplanar faces. Failing to do so will often result in unsuccessful operations.
Also boolean operations only work on two objects at a time, so if you have lots and lots of objects it will quickly become unpractical since you would have to preform Boolean operations for every possible combination of pairs of objects.
You will also end up with bad topology all over your model.
Search this site for Boolean, there's about one question of those every day. You will encounter most often found problems, caveats and solutions for them.

I used the Boolean modifier to make the correctly rendered example cubes, but it was impractical to use with the numbers of objects that I have.

I feared as much, I'd advise then using a different modelling technique if you want to use freestyle, one that is more compatible with its limitations and creates "correct" non intersecting geometry. Alternatively you could try this addon, though I am not sure you won't run into the same problem http://blenderartists.org/forum/showthread.php?282824-SVG-output-script

This is still aparently not possible with freestyle but can be faked in the compositor. See How can render overlapped object's edge freestyle line? for how this can be achieved.


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Armature X-axis mirror not weighting correctly
I have been rigging a model and have come across an issue that I haven't been able to solve after a lot of experimentation, basically, my current model is mirrored with the mirror modifier, and I am rigging it with X-axis mirror on.
Normally, when I weight paint say, the left leg to bone 'Leg.L', then it automatically weights the other leg (which is the mirrored side with the mirror modifier) to 'Leg.R' automatically, and it is doing that here for the most part.
The problem is, for some reason my 'Hand.R' and 'Hand.L' bones are not behaving in this way. When I try and weight the hand to 'Hand.L' it weights the vertices on both the left and right hand due to the mirror modifier on the model, rather than mirror only the left hand I am working on to 'Hand.L' and automatically apply the weights on the other side to 'Hand.R'.
I am fairly unfamiliar with rigging in blender using mirror, so I am not sure if there is a setting somewhere that I am missing, or why this part of the armature is suddenly not mirroring fine like the rest of the rig is. Any help / explanation would be greatly appreciated.
Apologies if this is a duplicate, I wasn't quite sure what the proper wording would be, I hope my explanation of the issue is clear enough.

This issue is, as you have identified, due to the mirror modifier. Technically speaking there is only one hand in the geometry data and the weight painting system is only reading one hand in two places, because weighting is technically a vertex group assignment system. If you apply the mirror modifier (I suggest making a duplicate of the hand if you aren't sure about needing to make changes later.) it will create the geometry for the mirrored hand. Then you can go back into weight painting and the x axis mirror should work as intended.


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Is there a 32-bit version of 2.76?
I'm new to Blender and I have just dopwnloaded Blender 2.76.
Unfortunately it doesn't seem to work under my 32 bits Windows7.
Is there a 32-bit version of 2.76?
Thanks.

Welcome John :) Yes, blender supports win7 32bit. All packages are listed here: http://www.blender.org/download/. If a problem occurs, then make sure it's really a bug and please report it: http://blender.stackexchange.com/questions/1377/best-place-to-put-bug-reports. Enjoy blender.se!

Thank you! I followed the link you gave and I've downloaded the 32 bit version. Everything works fine now.

Great John! Glad I could help!

As others also said, yes, and more: there here are two 32bit windows versions: a .msi (installer) and a .zip (archive). You could detail more what is "not working" for you, and any error messages you get, that would help understand what is causing your Blender to not work.
As an advice, since installing .msi can have issues sometimes, try the .zip version, it should work out of the box, just unzip it anywhere ad launch the blender.exe inside. If that blender works, it's just the .msi install process having issues of some kind...


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How to move selected edges toward 3D cursor?
I know that i can set Pivot point to the 3d cursor mode on the tool bar, and then scale selected edges, and edges will be scaled towards the 3d cursor. But how to move the edges to the cursor without scaling?

select your faces, use Shift+S then select "selection to cursor (offset)".

Thanks for your answer, Bithur! Your approach works great, but what if i want to move my faces not complete to cursor position, but little forward, or little back, how can i do this?

move your cursor a little forward or back. In the case of your screenshot, you could move your faces along their normals with Alt+S or select the transform orientation as "normal" and use G, Z, Z