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Is there a way to use renderman in blender?
The free version of renderman is coming out soon and I'm wondering if it can be pluged into blender. Is there a way to use renderman in blender?

This article might interest you

http://blenderartists.org/forum/showthread.php?251446-PIXIE-2-2-5-3Delight-Exporter-%28Updated-For-2-66%29

@NoviceInDisguise maybe you can put an answer to this

@Chebhou I think the answer is no, the one solution was lacking in support. Is that what you were thinking?

@NoviceInDisguise i just thought it would be better to write an answer to the question

@Chebhou Alright, I posted one

Edited for 2022:
Pixar now offers full support for their own completely rewritten Blender plugin.
https://rmanwiki.pixar.com/display/RFB24/RenderMan+for+Blender+24.0

This answer is now outdated as Renderman is now free and a plugin is available

This feature used to be supported, however it now appears to have been discontinued due to a lack of interest of the Blender community. Now that Renderman is free, the developer might re-launch the addon if contacted and enough interest is shown, or another person could do somehting similar, and quite possibly have better success due to the growing interest. However, as of now, this capability is not supported.


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Unable to split an edge as expected
I have selected one edge and would like to split it. When I click on the command in the menu, nothing happens. When I use the modifier, nothing happens. My selection on the object remains.
I am definitely in edge mode.
It is definitely selected and it is the only selected edge/face/vertex/object.
No UVs.
Shading: nothing selected, neither smooth nor sharp for anything.
I'm pretty new to Blender, so I apologize if this is silly/dumb.
This does not work:
http://blenderartists.org/forum/showthread.php?279119-Edge-Split-Not-Working
Stats:
Blender 2.71
17" MacBook Pro from mid 2009
OSX version 10.7.5 (lion)
8 GB of RAM
NVIDIA GeForce 9400 M 256 MB
2.66 GHz Intel Core Duo Pro

Is the title of the question connected to the content? They seem to be about different things.

What do you mean by the command in the menu?  What command are you using?  What do you mean by split it?  Do you mean that you want to divide an edge into two?  Have you tried using subdivide?

If you only want to split an edge into two parts, phrase it like this "How to split an edge into two parts" and your question will work. The term edge split is already used for something different you might not know yet. See also http://blender.stackexchange.com/questions/19131/how-to-properly-use-face-smooth-shading/19142#19142 Besides that it is always a good idea to explain what you expected.

I was trying to split it, using "Edge Split". "Edge Subdivide" does what I was looking for.
Chris, you got it right, thank you.
By "the command in the menu" I meant <press "space" to bring up the menu of commands and click "Edge Split", sorry for the confusion there.
Edge Split still seemed to do nothing. However "Edge Split" can only be seen in the rendering screen.

I hope I understood your question correctly, since the topic asks something else than the text. If I got it right, you want to know why you can not split a single selected edge.
I think the problem is that Blender can not connect two vertices with an edge twice.
If you only select one edge and try to split it, Blender would have to insert a second edge between its two vertices. My guess is that this collides with the internal data structure of Blender.
To solve this problem you would have to insert another vertex along this edge first, so that after splitting you will get a "ring" of four edges. Then there are no two vertices connect twice and Blender is happy.

Wait... so splitting an edge is NOT how you insert a new vertex? -- I don't see an insert vertex command, so how can I split one edge into two edges?

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How to move or slide an image in VSE
I would like to know if there is a way to make an image move or slide to another point using the video editor.

yes like within the frame

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Object looses its scale on keyframe change
I've made a static model of a mannequin to do some tests.
My problem is that whenever I scale a part of the model, or the entire mesh, then every time I move the time-line a bit (or Alt middle mouse. I'm used to zooming that way from maya) the scaled meshes return to previous scale, along individual centers.
Here's a image sample of the problem:
1 Before the scale

2 After the scale (note the time-line)

3 After moving the time-line*

This effect would also happen if I'd scale the mesh, and then export it as a FBX (without moving the time-line).
I've tried to apply the scale onto the model. In effect the elements of the model get incredibly small, when the time-line moves/I export it.
I would be very grateful for any help with this issue.
*I know it wasn't exactly by 5. My mistake. But it's visible that the current time has changed.

like this? https://www.youtube.com/watch?v=eTaR7jnJ1-o

You have part of your mesh animated. When you move the frame, it displays the current transformation of the keyframe with animation.

                                  Animated Frame         Current Frame
You can fix this by going into the dope sheet, the NLA editor, or the Graph editor
And delete the unwanted animation

          You can click here to delete                      You can also select all the
          the animation for that object.                   keyframes here and delete them.
You can keep the transformation without deleting the previous keyframe by adding a new one and animating the transformation.


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vertices with similar weights not moving at same speed

As the above image shows, whenever I move the armature that controls the upper arm, the corresponding part of the t-shirt moves slower than it. This is regardless of whether or not they have the same weights.
The picture shows them at different weights, but I tested to see if the same issue arises when all weights are the same. The whole object is composed of one mesh the t-shirt and the arm are all in the same mesh. How would I prevent the arm from moving through the t-shirt?
(I know I can delete the vertices that are blocked by the t-shirt, but this same error persists even then for the remaining vertices that are slightly inside).
I am using blender v2.72b.

Upon further playing around with the mesh, I found out that I should do the following to get what I want:

In edit mode, select the island of the cloth mesh, in this case, the t-shirt.
Press P to separate the cloth, click by "Selection".
Go to object mode, parent the rest of the mesh to the armature, with automatic weights.
Then parent the cloth just separated to the armature too.
Go to pose mode and move the body, the cloth will follow it.
Go back to object mode, select the cloth then the body, and then join the two meshes, to get back the original mesh.
Going back to pose mode and moving the armature around still shows that the cloth follows the body's motion.

That's it, this worked for me and I hope someone will also find it helpful. If anyone has a different way of approaching this, please share.

I have another method for clothing. Instead of parenting the cloth to the armature, select the skinned object, then shift+select the cloth. Press spacebar and type/click "Transfer Weights". Then apply an armature modifier to the shirt. This makes gives better results for me.


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How to get intersection of a specific object and the mouse in the BGE?
Still following the same tutorial as I was following so long ago :P
At about 9:30 he mentions using rayCast() to get the intersection of the ray and any objects with a specific property.
This sounds like what I want to do, which is get the location of the point underneath the cursor on only a specific object.
Here is my script:
from bge import logic

def main():

    scene = logic.getCurrentScene()
    cont = logic.getCurrentController()
    mouse_over = cont.sensors["mouse_over"]

    if mouse_over.positive:
        tracker = scene.objects["mainTarget"]
        crosshair = scene.objects["Cross_hair"]
        floor = scene.objects["Floor"]
#        tracker.worldPosition = mouse_over.hitPosition
        tracker.worldPosition = crosshair.rayCast(floor, "isTrackerFloor", 0, 1, 0).hit

I think it should be working, except I keep getting type errors from the rayCast function arguments. I've tried shuffling them all around, but had no luck (with the above arrangement it throws TypeError: must be str, not int, which I assume means I have the property name in the wrong place?).
What is wrong with the arguments? and If the above technique doesn't do what I want after all, is there any other way to do this?
Blendfile

I deleted my answer since it does not seem to work. Another thing you can try is to set all function arguments. Set those you do not need to None (for objects) or 0 (for numberical values).

@maddin45 It seemed to work, but I had trouble getting the return value. I eventually tried this: object, hitpoint, normal = crosshair.rayCast(floor, crosshair, 0.0, "isTrackerFloor", 0, 1, 0), but object, hitpoint, and normal are all none (even with the cursor over the correct object)? Plus I only want/need the hitpoint. I also uploaded my .blend, in case that helps.

yes that helps. What I have found out so far is that if you set the 'dist' attribute (for example to 100.0) you will at least get return values that are note none, but the values seem to be wrong.

@maddin45 I have a feeling something won't work, because if I understood the documentation correctly, the ray is fired towards the origin of the target object (so the location of the mouse won't affect the location of the intersection)..

@maddin45 Is there any other way to make the ray only hit a specific object? I want to use an object which is not a plane, so the second method in the tutorial won't work.

I guess you are right. But rayCast also accepts two points as objto and objfrom arguments. Maybe you can mix this approach with mouse over and use the raySource and rayTarget values of the Mouse Over sensor as inputs.

Somehow I cannot log in to the chat. But I think I found a solution: Use          object, hitpoint, normal = crosshair.rayCast(mouse_over.rayTarget, mouse_over.raySource, 100.0, "isTrackerFloor", 0, 1, 0) and add a Mouse Over sensor to the sphere which is connected to the python controller. The cone is looking a bit weird but the cube is now following my mouse. I uploaded the modified file.

@maddin45 What sphere? I don't have any sphere in the scene (that I know of).. The cone was weird with the original method using just a mouseover sensor too, I think that'll be a separate question (I've tried rotating it, applying the rotation, not applying the rotation, etc.. everything I could think of :/).

I meant the cone, it just looks round from the camera view when the game engine is not started :D

@maddin45 Perfect, thanks :D (I even got the cone working) Add it as an answer and I'll accept it :)

Alright, added the answer. Glad I could help :)

After some discussion with gandalf3 we found a solution:
The main problem was that the rayCast function will cast a ray between the centers of two objects: Those passed as objto and objfrom arguments. Thus the ray's hitpoint always was the position of objto, not the position over which the mouse hovered.
But rayCast also accepts 3D points as inputs. The trick is to use a Mouse sensor, set to 'Mouse Over Any', and connect it to the Python Controler which holds the script:

In the script one can use the rayTarget and raySource properties of the mouse over sensor as inputs for the rayCast funtion. The modified code looks as follows:
from bge import logic, render

render.showMouse(False)
#from bge

def main():
    scene = logic.getCurrentScene()
    cont = logic.getCurrentController()
    mouse_over = cont.sensors["mouse_over"]

    if mouse_over.positive:
        tracker = scene.objects["mainTarget"]
        crosshair = scene.objects["Cross_hair"]
        floor = scene.objects["Floor"]
        object, hitpoint, normal = crosshair.rayCast(mouse_over.rayTarget, mouse_over.raySource, 0.0, "isTrackerFloor", 0, 1, 0)
        tracker.worldPosition = hitpoint

One further note: The 'Edit Object' actuator which is set to 'Track To' seems to make the affected object point to the target with its local y-axis. Make sure the object with the actuator is rotated correctly in edit mode.


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Any way to get a specified magnification effect?
I'm trying to simulate the magnification of a rifle scope. However, I don't want it to be a random amount, as rifle scopes typically have a set range of magnification (for example anywhere from 6x to 14x).
I've done research prior to posting this, and I know having two UV Spheres scaled down from their poles and at different overall sizes would generate the effect I'm looking for, but is there a way to get a specified setting say like 4x zoom? I'm not looking to get a range to adjust from, just one level of magnification.
Also, if it helps, I'd preferably like to do this in the Cycles rendering engine if at all possible.
I made a rough model of the ACOG 4x rifle scope and studied up on the internal parts. It contains two eyepiece lenses, a roof prism and the objective lens, which I modeled. It works somewhat, most likely because I made the prism too square.

what do you need the magnification effect for?

Rending using caustics in blender like you suggest will be verrrry slow.

Well, I'm attempting to model the actual scope itself, and I want to get as realistic as I can.

I would recommend not trying to actually model the lenses to magnify the image, but rather place a camera in front of the scope with a higher Focal Length.
Then in the compositer you can add the scope's camera view to the final image.

I'll try that, but the thing is that I'm actually making a model of a rifle to go along with this as well, so I'm not looking for a camera view through the scope itself.

@Forged-In-Steel so you are interested in the inside of a scope, and how to model it, not really a image rendered as if looking through it. Is that right?

@Forged-In-Steel Something more like this then this?

In a basic sense, yes, but not a full-on modeling of the scope's interior (unless it's ABSOLUTELY necessary, then sure) I'm modeling the actual body of the scope itself (I just got a reference photo of an ACOG 4x prior to this comment)

@Forged-In-Steel so if you are just modeling the scope, do not care about the interior, or looking through it, then why do you need to know how to get a specified magnification effect?

I guess I worded it wrong... or maybe I took it in the wrong direction. I did want to look through it, granted it looks like I didn't want to. Sorry if this seems roundabout. So basically the full interior is necessary for this, correct?


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Hide custom properties in the UI panel with python
I tried to use options={'HIDDEN'} when I declare my property but it doesn't seems to work. Is there a way to hide a custom property in the UI panel?

options={'HIDDEN'} prevents operator properties from being auto-drawn. If you define a custom draw() method, nothing will be hidden.
import bpy

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"
    bl_options = {'REGISTER', 'UNDO'}

    prop = bpy.props.BoolProperty(options={'HIDDEN'})

    def execute(self, context):
        return {'FINISHED'}

def register():
    bpy.utils.register_class(SimpleOperator)

def unregister():
    bpy.utils.unregister_class(SimpleOperator)

if __name__ == "__main__":
    register()

To hide global properties, simply don't draw them. You may use conditions to draw properties in certain circumstances:
class HelloWorldPanel(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Hello World Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "scene"

    def draw(self, context):
        layout = self.layout

        if context.object is not None:
            layout.prop(context.object, "name")

Thx @CoDEmanX ! that helps me understand the options={'HIDDEN'} statement. I'm not sure I understand the 2nd part of your answer though. Because custom properties are drawn automatically in the "Properties" Category in UI panel (N panel), I'm looking for a way to override that and hide them instead. Is this even possible ?

The HIDDEN option hides individual operator properties in the Redo panel. If you don't want the user to tweak these properties, remove UNDO from bl_options. If you just want to visually hide all operator properties in the Redo panel, define an empty draw() method: def draw(self, context): pass


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When I join particles they somehow multipy
I've created a particle system (grass), converted the particles and moved them to another layer to get the grass as separate objects. Now I want to join them by Ctrl j. However, when I select two grass blades and press Ctrl J additional blades appear. What am I doing wrong?
What information do i need to provide?

When you convert a particle system, the new objects all use the same mesh data. This is the same as making a linked duplicate. When you join two of these objects together, every other object using that same mesh will show the same duplication.
Blender seems to recognise this, so that if you select all of the particle objects and Join them in one go they will be joined into one object without the duplication. The original object you used for the particle system will receive the same duplication so you may want to separate it first.

In the mesh data properties there is a number between the mesh name and the 'F' button (only shown if it is greater than 1). This number indicates how many objects are using this mesh data. By selecting the original object used as a particle you can click this number to separate the object from the others preventing it getting the same duplication when you join all of the others.


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Play a sound triggered from emitting a particle
I have a spaceship and it has a particle system for firing lasers. I am wondering if there is a way to play a sound when it emits a particle.
I have tried grouping the particle with the speaker and emitting the whole group but that doesn't work. I don't know if it should or if I am doing something wrong.

In 3D animation the sound and video are generally two separate things. Supposing you did get your sound to play with the particle system, you would still need to out put the whole animation to a video format including sound. Which rules out a image sequence, the best way to render an animation.
It will be easier to just render out your animation of the ship firing its lasers. Then in something like the video sequence editor (or any other video editor) just add the sound file at the right time to match the firing lasers.

This seems like something you'd want to do in the game engine. You could probably place a speaker near (right in front of/next to) your "guns" that is triggered when a particle comes within a certain range.


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Can I add a driver many bones at the same time?
I want to add a driver to a lot of selected bones at the same time, is it possible?

Possible duplicate of how to copy drivers to multiple Objects?


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Cycles volumetric object with intersecting mesh
Hi I'm trying to make a character that looks like he's made of mist or smoke in Cycles. The Volume absorption works pretty much as I'd hoped.
But once the character is posed, any little mesh intersection shows up as a 'hole' in the volumetrics.
Does anyone know a possible solution or is this just a limitation of volumetrics at the moment?
The armpits and elbow here are an example.

Maybe try Remesh modifier on top of your mesh? Just move it to the bottom of your modifier stack and do not apply it.
You may expect different visual bugs and shape degradation, however for volumes it could work.

Well this is a surprising solution I never would have thought of. With octree set at 8+ and smooth on this works pretty well! I'll have to have the modifier off for animating and drop it in for rendering though. Cheers.

The holes you see are from the mesh intersecting with itself, which will confuse the choice of being inside or outside of the mesh with volume shading. Using the remesh modifier with smoothing can relax the mesh enough to prevent the intersection.
Another approach that can give more control is to use shape keys. While the mesh is posed in that position, create a shapekey that moves the necessary vertices to prevent the intersection. If you are animating you can add keyframes to the shapekey value so that it is applied as the character moves into that pose.

Thanks for the suggestion sambler. I had considered using shape keys, until I tried a pose where the character had his arms crossed. There were intersections with fingers/thumb/arm/body. Yecch! Will see how this goes with Remesh for now.


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Does Blender API have any evaluation function for Bezier curves?
I'm trying to export Blender Bezier Paths to Unity, so that Unity objects can follow along those paths.
The 2 ways to do this that I came up with so far are:

Blender script creates an empty for every control point in the Blender path, then those get imported into Unity as empty game objects (aka transforms) and from within Unity I can calculate B(t) based on the control points.
Blender script takes a "resolution" parameter, which it uses to
evaluate the path and instead create an empty along the path for
each sample. Then those get imported into Unity as empties and from
within Unity I just have the objects follow this checkpoints along
the path.

For approach 2, I'd need to evaluate the spline inside blender. And I was hoping that bpy.types.Curve would have an eval(t) or similar method but I haven't found anything in the API so far.
So my question is, is there anything in the Blender API for evaluating or do I need to write the evaluation code myself?

Ok I found it: mathutils.geometry.interpolate_bezier().


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How to flip the face of a closed 2D curve (similar to normal flip for mesh)?
I use Blender 2.69. When I create a closed curve (for example, a circle) and make it 2D with the properties editor, it becomes filled.
Since I work with backface culling on (because of the application of the objects I make), only one of the sides is visible. In the case of a just created circle or a figure imported from SVG, it's the bottom side. In the latter case, it is especially annoying, because the figure appears mirrored.
Is there a simple way to flip the face (similar to flipping the normal for a mesh face) so that it shows on the opposite side of the curve?

You can swap the normal of the face by flipping the directions of the curve.

Select the curve
In edit mode go to Curve -> Segments -> Switch Direction. You can also do this via the space menu be searching for "switch direction"

Thanks! That worked, except I needed to select something first while in edit mode. It's annoying that it can't be done while in object mode, because I have to do it to each polygon imported from SVG, switching back and forth and selecting something for each polygon. Any clue about whether it's possible to do it while in object mode, to be able to do it in bulk?

You can do that using python. But also maybe you should join all curves together first?

Depending on what you need, scaling -1 in a global direction might work.

I tried that before asking. It flips the face and mirrors the curve, so it is equivalent to rotating 180°, thus not solving the mirror problem.

You need to restrict the scale to one direction only (e.g. press S; Z; -1 ).

Yes, this works too. It failed for me because I tried it in edit mode, but in object mode it works, which is an advantage. It has the drawback that applying the scale reverts the effect, though.

Of cause this is a quick and dirty approach. That is why i wrote "Depending on what you need". For rendering "Front Face" or "Back Face" this should be a sufficient fix thought.

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My Objects won't render
Well, I make Minecraft Animations and I was moving from Blender 2.69 to Blender 2.70. The version move was successful. It rendered properly n' stuff. I was playing around with nodes and render layers. After a while I took a render. and all of a sudden every thing did not render. Only the things Ia moved into the 2nd object layer which i moved back to the 1st render layer. Now what. I've been stressing, trying to fix the issue but it won't render.
I'm pretty sure that i did not do an accident of some sort but i probably did. The materials are not transparent. The camera distance is way over how far this is because I have other scenes(old copies of this new one) that still render. Help!
It exists in the 3D view-port but not in the render :( Help?
This is all that renders

That sucks
3D view-port of what it is actually meant to look like

Another render

What is actually meant to be, with the render layers panel

Here is the node editor, pretty simple because i usually do the compositing after the animation is done.

Notes: When i was taking a snip of the view-port, i changed it to render view and it was all invisible. Also the image above is set on the last layer but even if i set it to the one with all the objects nothing would render
Answer : Everybody don't worry i found the problem, apparenttly all items were restricted to render for some reason. Not sure why. It might have been when i was playing around with the new flight system(Shift+F) i pressed (W) and accidently pressed Restrict Render Unselected. Anyways this problem has been solved, what do I do?

Is it possible you could upload the .blend (or at least enough of it so that the issue is apparent)? There are many possible causes and it's hard to guess what might be the issue in your case without more info (best gotten from a .blend).

At the very least, post screenshots of your render layers panel and tell or show us what's in each one. Check the focal length of your render camera also.

The file is just too large and with my internet, it's not gonna happen. I may upload more snapshots though. The focal length is 15.66 Blender units

Have you tried recalculating the normals(CTRL-N)?

Can you provide a screenshot of your compositing node editor setup?

What are your material/texture UV settings? Is it possible they got messed up somehow?

Everybody don't worry i found the problem, apparenttly all items were restricted to render for some reason. Not sure why. It might have been when i was playing around with the new flight system(Shift+F) i pressed (W) and accidently pressed Restrict Render Unselected. Anyways this problem has been solved, what do I do?

The post will remain closed as you have identified the problem and it's a localized issue that doesn't really correlate with the question.


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Changing the grease pencil brush from the API
How can the grease pencil brush be changed from the API?  The default is Pencil, but in my addon I would like to use the Pen.  I cannot find this anywhere in the documentation.
# Define grease pencil parameters
gp_mat = bpy.data.materials.new("my_mat")
bpy.data.materials.create_gpencil_data(gp_mat)
gp_mat.grease_pencil.color = [0,1,0,1]
bpy.context.scene.tool_settings.gpencil_stroke_placement_view3d = 'SURFACE'
bpy.data.brushes["Pen"].size = 5

# Add grease pencil to scene
bpy.ops.object.gpencil_add(type='EMPTY')
bpy.ops.object.mode_set(mode='PAINT_GPENCIL')
gp_obj = bpy.data.objects['GPencil']
gp_obj.data.materials.append(gp_mat)
gp_obj.active_material = gp_mat

# Change brush to pen
_________________________________________  # What goes here?

You can change the active brush via the context tool settings like you set the
gpencil_stroke_placement_view3d in your code:
bpy.context.scene.tool_settings.gpencil_paint.brush = bpy.data.brushes["Pen"]

Of course you have to use the respective name of your desired brush.

Thanks PietersonFindus!


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Why does Blender tell me this mp4 is an unsupported format when open it in the VSE?
I have a video that I shot with my Samsung Galaxy 7, and I saved it to my computer. When I open it in Blender VSE, it tells me that it's an unsupported format. I have the latest, 2.78a. Am I doing something wrong? Should I render it in something else?

How are you opening it? Does the video play well in other software in your computer? If nothing else works try converting it to another format with a conversion software like handbrake or similar

Also check that it isn't a corrupt file when transferred to computer.


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Render is taking way too long
So I'm rendering an animation of 420 frames and each frame is taking more than one hour. I have two render layers, both with the same settings. One is the background and the other the principal object of my scene.
I don't have many meshes.
Here are my render settings am I doing something wrong?

Here  is what I'm rendering

My computer specifications are:

Intel Core i7-2600 CPU 3.40 ghz
Ram 8GB
Nvdia Geforce Gtx 555

If 50 samples are enough for your scene, then uncheck Square Samples. Atm you render at 2500 samples and that's quite much (again, depends on scene). In anyway I'd enter exact number of samples rather than squaring them. If doesn't help, http://blender.stackexchange.com/questions/31973/why-is-my-render-taking-so-long

@Estefanía De La Vega García, it would be very helpful in answering your question if you would post the specifications of the hardware that you are using to perform the render.

Intel core i7-2600 cpu 3.40 ghz Ram 8gb Nvdia Geoforce  Gtx 555

Try and set the PNG from RGBA to just RGB. Your render seems like it wont need any alpha, so it would probably help for your pc to not take in to account an alpha channel when rendering, since your scene doesn't need it.

Calculating an alpha channel does not add an appreciable overhead, and even if it did, selecting RGB output files does not disabling alpha calculation. It merely prevents it from being saved. The render buffer itself is 32bit/channel RGBA no matter what you select.

1 hour is not outrageously long for a 1080p frame, depending on your hardware (of course). With only a screenshot of your render settings, it's difficult to suggest too many optimizations. Here's the best I can do:

I notice you have 4 diffuse bounces, but only 2 glossy bounces. While your particular scene might be different, in most cases diffuse bounces are less important. In most scenes anything over 2 is a fairly subtle change. It's fairly noticeable if you compare renders with, say, 2 vs 4 diffuse bounces, but if you don't have that comparison the missing light from the extra bounces isn't obvious. Whereas with glossy bounces often larger numbers are needed to avoid black reflections. Again, I'm speaking generally here. I have not seen your render, and this may not be the case for your particular scene.
2500 samples (50^2, since you have square samples enabled) is a fairly large amount of samples. Your scene may not need that many.
Branched path tracing may be helpful, particularly if your scene has empty regions or tricky lighting. Branched PT is not always faster (such as with motion blur or DOF), and has more memory overhead on GPU so it's not always helpful, but it may be. See this answer for more info: What is branched path tracing and how is it useful?

I changed some render settings and the render goes faster but now I have to much noise

Possible you lowered samples too much? It's very difficult to say, could you update your original post with an example render output, at least?

Sure Im gonna add the render of two hoours and the new one

Try and also increase your tiles. Here is a link to show you how it compares to have higher tile sizes with the gpu, than with the cpu. https://www.blenderguru.com/articles/4-easy-ways-to-speed-up-cycles/ In the bottom, there is a chart too.


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Why is my Wacom Cintiq Companion eraser not erasing in sculpt mode?
When I switch to sculpt mode and use my eraser with my wacom cintiqu companion, blender version 2.77a will display a red dashed circle inside the drawing brush icon and will not allow erasing. When the 'subtract' brush is activated, it will erase like normal, but not with the eraser. I have not been able to find a solution on the internet yet. If someone could help me, I would much appreciate it!

Welcome to BSE Nikolai. As far as I know there is no erase in sculpt mode - Add pulls the vertex along the normal outward, and Subtract pushes them in. You can either do this by the menu buttons or holding down  CTRL  to reverse the operation. The eraser still works but has no function on the meshes. If you had for example grease pencil strokes, you could erase those even though you are in Sculpt mode. The same is also true of Edit mode.


text:
Why do I get weird shadows on my baked normal map?
I baked a normal map,
however, there's weird shadow.. what is the problem?
The first picture is when I bake the normal map options:

Did you recalculate your normals? Are all faces the correct way?

Try baking with subsurf modifier set to 2 maybe?

It could be the color space of your texture node, it has to be "non-color" for normal maps.

I think you're seeing z fighting which is when you have two nearly identical meshes on top of each other.  You have both dragons visible in the outliner, you should hide one of them.

I think that's not the way to solve... I try this way twice


text:
Why are squares appearing on my model in Eevee?
I created a lighting scene in blender 2.8. with a plane as the background.
For now I hid my objects because they are not the problem here. And I also like the positions of the lights.
While rendering I noticed that you can see the squares of my model. Which is weird because I put on a subdivision surface modifier as well as Smooth Shade.
I think it's because of my light settings, I don't know what to change though.

Blender file--> http://pasteall.org/blend/index.php?id=51823

The problem is with Area.001 Contact light Softness. I don't see the solution without decreasing of it.

@RUben thank you!!


text:
Changing a material effects both text objects
I am making a Banner for a friend, I have it mirrored and pretty, Same text twice, The main one with bevels and Glass. The one behind it as an Emission source for light to get a nice reflection.
Now here is the problem, I was wondering why it wasn't detailed, When I move back and fourth between the two Text items, They keep moving the properties! Example, I change the color of the Emission text, Suddenly the Glass text isn't glass but it also has Emission property now, For some reason when I change anything on one, It changes in the other.

do they have separate materials ?

Most likely this is because both text objects are assigned the same material (this could happen if you duplicated one from the other).  If a material (or any other datablock, i.e. particle system, image, etc.) has multiple users it will display the number of users in a small box to the right of the material name.  To make a single user copy of the material simply click on that box.

The material "Material" has 2 users, clicking on the 2 box will create a new material with all the same properties and name it "Material.000".  Changing this new material will not affect the original material "Material".

Hmm... I thought that duplicated objects made a duplicate of the material as well. Hmm... if that isn't so, it certainly makes things easier.


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Does installing/running Blender tamper in any way with my system/settings or install additional software/required components?
My question is, does using Blender (since it doesn't require an installation as far as I understand) tamper in any way with my system, install additional/required/third party software or make any long lasting changes to my registry?
I'm using Windows 8.1 64bit with all the current updates at the moment.

No it doesn't modify your system, provided you are using the self-contained .zip version.
The self-contained .zip version is just that, self-contained. It will - of course - put data where-ever you tell it to. Animation output or other temporary files will be written where you tell Blender to put them. Temporary files (in C:\tmp\ by default) are deleted every so often.
In addition to the outputs mentioned above, the Blender Windows Installer will also make a link in you start menu, (possibly) on you desktop and will associate .blend files with the Blender executable. This file association is done via the registry but should be harmless.

Just to be clear, only temporary files (files in C:\Temp) will be deleted. Saved renders/animation output will not be spontaneously removed ;)

@gandalf3 Right, no more answering questions at 1am local-time for me (and then editing at 3am) ;D


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How can I unapply a subdivision surface modifier?
I accidentally applied a subdivision surface modifier, but I don't want that. I tried to undo it, but that is not working. Is there any other way to do this?

You can discover the global history. If you can find the operat，then you can back to there by click.
following the link：
http://www.blender.org/manual/getting_started/basics/undo_and_redo.html?highlight=history


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How to Model a Keyboard key?
Keyboard keys sound easy but their particular shape is really weird, and keeps tripping me up. Specifically my keyboard keys, but I'm pretty sure they are similar to other keyboard keys.
A few photos for reference:
The corners are rounded and the top is sloped inward.

But we can't forget that the top (that is already slopped inward) is also slopped downhill.

I've tried starting with the rounded corners, but I can't add the slopped top without some horrible triangle topology. I've also tried starting with the slopped top, but then I have no idea how to add the corners.

Do you know about proportional editing? (http://wiki.blender.org/index.php/Doc:2.6/Manual/3D_interaction/Transform_Control/Proportional_Edit)

Also, bevel will be useful:  http://wiki.blender.org/index.php/Doc:2.6/Manual/Modeling/Meshes/Editing/Subdividing/Bevel

Yes I'm sort of familiar with both of those, but I don't have a clear idea of how they would be used best here.

This is a basic modelling technique, use part of a circle for the concave top, and just scale the base and rotate to make it fit the reference. IDK if this answer would be any help or not.

Keep in mind that there are other key shapes for different boards. the itsy-bitsy bumps that get worn of within two days can just be done with a simple noise texture set veeeery small. Adding oil and worn parts from fingers will be the hardest, but can also be accomplished with a texture.

@ARadish I did not ask about bump maps or textures, just the modeling.

In short, start from a cube. (in the gif I have a mirror modifier to save time)
Delete the bottom face.
Add loop cuts for the rounded top.
Position the top correctly, by simply G grabing, and R rotating and S sclaing the top geometry.
Use proportional editing O to create the dip in the top.
CtrlB to bevel the vertical sides.
(optional) Remove the Ngons in the top, that beveling the sides created.
Bevel the top ridge to make it smother and more realistic.

Always so obvious and simple, my thanks again David. Also, how do you make those gifs? What software?

@meed96 I use LICEcap, others here use GifCam also very good, both are free. For the key display, I use either Screencast Keys, or KeyCastOW. See this on how to get the gif into the post.


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Cause of Alpha or Black Artefacts in Render
This is my Minecraft Animation. It is made in Blender Internal and is intended to be rendered in Blender Internal. The animation consists of me running infront of Minecraft trees. These trees are mapped with UV textures of Minecraft Leaves with alpha turned on so that the leaves are transparent in places. The Animation starts at frame 8 and ends at 40. This is not a case Z fighting.
However when I render the animation I get square alpha (sometimes black pixel) artefacts in the render. Every frame has diffrent result but still has the artefacts. This is what it looks like. The white is the alpha. Open in a new tab for closer inspection.

As I said some frames have this problem and some don't

This one has AA disabled. This makes the alpha only one pixel each. (Open in new tab to see individual pixels)

This problem does not occur in the rendered mode viewport.

Leaves' Material Settings

Leaves' Texture Settings

Edit: I decided to restrict the leaves from render and this is the result I have. Pretty ugly. Also added, glare and vector nodes just fyi.

I then decided to remove the wood as well and now this happened.

And now there's black and alpha.

Here is a link to a video showing the problem.
What is going on here! Is this blend file corrupted? Please if you know the answer or what causes this please mention this down below.
And because you asked here a stripped down version of the file: https://www.dropbox.com/s/4q5qfsmjv7umtbh/Stripped%20Down.blend?dl=0

It might be Z fighting. Is it possible you have duplicates of the trees which are only visible in the render?

No sir. I thought it could be that as well but nope. Editing the question to add another screenshot.

Is it possible you could upload a .blend which demonstrates this behavior?

@gandalf3 I already mentioned up their that I could not as my internet connection speed would take a long time to upload the file.

Well can you shrink down the file in size? Leave only 1 tree there to showcase the behavior with only couple of textures packed? The file should be small enough then

@Jerryno Uploaded.

The artifacts are not from z-fighting, but from transparent auto shadows bias.
Just turn the option off:

Shadow auto bias on:

Shadow auto bias off:

Elaboration:
There was once bug which was (supposedly) fixed for 2.68:

Found the cause of the problem, it's due to the ray bias options that tries to avoid bad ray traced shadows.

It's supposed to eliminate shadow artifacts on smooth shaded surfaces where the shadow terminator is - like this one (I think..):

My guess is that blender sometimes fails to get it automatically right, setting it to fix value then works better.
Or making the surface flat shaded should work also.

Thanks so much :D Well that's the last time I use the Blender Mineways Python script. Thanks.


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What do green/brown(orange?)/yellow attribute highlights mean?
Shown here, a green (location (x,y,z)), brown (rotation (x,y,z)) and yellow (scale (x,y,z)) colored attribute highlight. What do these mean? (And where are they documented?)

Its always interesting when the question gets near zero votes yet people are clearly voting for answers.  One vote for you.

These colors all have to do with Keyframes.
Yellow: Keyframe has been set on current frame
Green: No Keyframe on current frame
Orange: The property has been changed but a keyframe hasn't been set
I could not find where Blender actually documents these colors though.

The linked answer from @Rich Sedman (Thank You Rich) points to this document where the colors are mentioned :) https://docs.blender.org/manual/en/dev/animation/introduction.html#animation-state-colors


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How to add modifiers using python script and set parameters?
I've found some code that could add a modifier but none can set parameters like Octree.

What modifier is this?

You can add a new modifier to an object with ObjectModifiers.new(). If you store the result of calling ObjectModifiers.new() in a variable (in the example below I call it modifier) you then have access to all the properties of the new modifier:
import bpy

object = bpy.data.objects['Cube']

modifier = object.modifiers.new(name="Remesh", type='REMESH')
modifier.octree_depth = 5

You can see the type of modifier by hovering the mouse over the modifier in the Add modifier menu and you can see the name of the properties by hovering over the properties on the modifier.

how do you figure the parameters of each modifiers ?

@Phil If you have Python tooltips enabled you can just hover over the values in the interface.

If you mouse over the field you should get a pop-up that show you a python expression for what the field refers to.  Since my knowledge of modifiers is far from encyclopedic I can not reproduce your situation in my blender.
Nevertheless, mouse-over is a standard technique for figuring out the python path to a field (although there are some data blocks whose path is complicated enough that you just end up with a ... in the middle)

well there is no hint on these fields, hence my post, but I used autocomplete in python console


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Why I am I unable to mix matrix nodes multiple times with Animation Nodes?
I have some nodes setup that make use of the "mix Matrix" node with a specific factor input. It works great. Then I wanted to mix that mixed matrix with another combined matrix, but at that point it wont work anymore. So I guess my question is, is it possible to use multiple mix matrix nodes to mix "mix matrix" nodes? (sorry if it sounds convoluted)

Okay, So, after some testing I realized that the output of a mix matrix node is actually a "result" (mind you im not a programmer) which gets inputed into an "object matrix output" node, so I simply connected an "object matrix input" immediately after the former and began a whole new sequence of Matrix calculations and it seems to work perfectly as I wanted. –


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Why is my mirror only reflecting things that are close to it?

I am trying to render out a scene of a bathroom. I am attempting to make a mirror material. It doesn't reflect anything that isn't very very close to it. I made a cube and put an array modifier on it and colored it blue to see how far the falloff went. As you can see it doesn't render all the cubes. Also for some reason, it reflects the front face on the cube closest to it as grey.
My node set up is not convoluted. It is simply the Principled Shader, but with adjusted settings, as you can see below. I would like the mirror to act as a mirror in real life as much as possible. I am using Eevee and I need to stay in Eevee for my purposes.

Eevee has its limitations, thankfully there is an easy solution:

Shift + A -> Light Probe -> Reflection Plane
Move and scale the Reflection Plane to fit the mirrored surface
Center the Reflection Plane on the mirror, then nudge it forward slightly

That's it. Enjoy!

So this worked, almost. I will mark it as correct since it did the minimum if what I wanted. It doesn't display the materials that I have made in a more complex node set up as grey


text:
How do I rotate a bone without effecting the connected bones?
I've been looking for answers to this problem, but I'm too much of a newbie with rigging to understand some of your answers.
So here's the thing: I'm trying to modelize and animate steelix:

Considering his snake-like shape, he's not so hard to rig and animate, and this is what I made:

But here's the problem: Steelix's spiked boulders can rotate on themselves, and with this rigging, whenever I rotate a bone, the whole body parts connected to this bone also rotates.
What should I do to make that the boulders rotate only on themselves?

Go into Bone Edit Mode of the Armature. Tab
Select the spiked_boulder bone and duplicate it. ShiftD
For further convenience, let's scale this bone down, so we can discern it later on. Let's name it spiked_boulder_rotation.
Parent spiked_boulder_rotation to spiked_boulder. CtrlP
Assign/Parent the spiked boulder mesh to the spiked_boulder_rotation bone.

Now you can animate the movement of the spine in a standard fashion. The child spiked_boulder_rotation will rotate along its parent moving the geometry. Now animated the Y Rotation of the spiked_boulder_rotation if you want to additionally rotate the spike geo.

Nice! Thanks Leander! I think I'll upload the animation and post the link here soon if I manage to pull it off quickly.


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Torn Mesh when transparent?
My mesh looks torn with little holes when it's transparent but totally fine when opaque. Any idea what could be causing this and how to fix? EDIT: none of the holes are visible in edit mode, only if the object is transparent in object mode. Thanks!
Here I have some images. All are in object mode without any modifiers at all.
Transparency:

No transparency:

Again, no holes are visible at all in edit mode and are only visible when the object is transparent in object mode.
During a render with transparency on, it looks fine too! Only in the 3D viewport with transparency there is noticable tearing/blocky-ness.

This problematic behaviour can't be changed.
But since it is only a viewport problem, it won't affect the render. The backface and the frontfaces are both visible and don't get rendered properly. There are two temporary options.

Don't show transparency in the viewport. Toggle off show transparency under Properties > Object. To preview the effect you'll have to use the render preview ⇧ ShiftZ.

Enable backface culling, that way the backfaces don't get involved in the viewport render. Transparent frontfaces are combined correctly.


text:
How do I reduce edge loops without weird geometry?
I'm trying to understand/learn modeling and I'm having problems reducing the number of edge loops I have without super weird geometry or awful triangles.
Here's a picture of what I'm trying to achieve (but without the weird geometry).

What's the best way to approach this problem?

Yeah but I want to keep the 3 edgeloops on the left and also keep the 1 edgeloop on the right, not delete them. Some areas of a model require more geometry, which then proceeds into an area that doesn't need as much.

Then you won't be able to go without some ngons. And I think these may be 5-vertices polys

Well if that's the only option, then what's the "cleanest" way to go about it? is really what I'm asking.

Do you mean you want to keep the vertical edgeloops at the left or the horizontal edgeloops?

@FacebFaceb Sorry if there was any confusion, I'm only referring to the horizontal edge loops. I want 3 horizontal edge loops on the left and one horizontal edge loop on the right, but without the weird transition geometry.

First off there is no way to reduce 3 inner edges to 0 without adding a loop cut somewhere, or using triangles or Ngons.
You can reduce three inner edges down to one inner edge using only quads.

However you can reduce four inner edges down to zero.

I didn't specifically want to go from 3 to 0, I just wanted to go from X to X-1

Can you generalize your technique? How do you approach reducing detail...this is a really great post, I wish it had more though...


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BGE: Path follower wait in a specific point
How can I modify the following .blend file in order for the cube to wait 10 seconds in "point.004". I don't want to use the sleep function.
Here is the file

You can simply switch to a different state, in which you do nothing but wait to switch back to the original state.
That could look like this:
def wait(self, seconds):
    self["clock"] = 0
    sen_prop = self.sensors["Property"]
    sen_prop.min = str(seconds)
    sen_prop.max = str(seconds + 1)
    self.state = 2

And then to use it:
wait(cont.owner, 10)

The function assumes the presence of a Timer property called "clock", and a property sensor (called "Property") in state 2, connected to a state actuator that switches back to the original state.
Here's a modified version of your demo, that shows this in action: track_to_point.blend


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What are face normals?
I've seen the term Normal being used in many places, but I'm not quite sure what it is or what it's used for; what exactly are they?

Already did. That's mostly were the answer originated from.

Normals are vectors that are Orthogonal to the Tangent plane of a curved surface; Or simply orthogonal to a face.
The Normals are usually used to determine a surface's orientation toward a light source for shading. Most common examples:

Flat, Goraud, Phong shading

Fresnel, Refraction, Reflection effects
Bump, Normal, Displacement mapping

Normals are generally normalized to length 1 (in arbitrary units), otherwise calculation errors, and thus artifacts, may arise. Since they only point one way they are also used for back visibility culling (when double-sided is off).
That's why it is important for the normals to be consistent and coherent (i.e. point in the correct way - outwards of a model).

Normals are also used for bump and (duh) normal mapping and smooth shading.

@PGmath well, yeah... Those were just some examples.

@NoviceInDisguise Yea, it felt kind of dumb saying that normal maps mess with normals.  But then again, when I first saw a normal map I thought “that doesn't look very normal to me!”

Besides the mathematical explanations, I think a picture will help to understand what is meant by normals and perpendicular. The faces having a normal (blue lines) pointing to a light source are rendered brighter than the faces pointing into other directions.

You can toggle the display of normals in the Properties Panel (right panel N):

+1 if you also add screenshot showing how you turn on the normal lines display.


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What's the difference between the various Open Subdiv compute types?
It seems there are 5 different available "compute types". what are these compute types? What's the difference between them?

The difference relies in in which device the actual calculations are done. CPU and OpenMP are run on the CPU, while GLSL Transform Feedback and GLSL Compute are run on the GPU.

CPU - single threaded CPU implementation. it is mainly useful in cases when GPU compute is possible and threaded CPU option causes artifacts (it is unlikely to happen, but still possible).
OpenMP - multi-threaded CPU implementation. It is similar to threading model of old subsurf code. Use it for maximum performance in cases when GPU compute is not available.
GLSL Transform Feedback - uses GPU to perform calculations, has minimal requirements to video card and driver.
GLSL Compute - uses GPU to perform calculations, supposed to be more efficient than Transform Feedback but also has higher requirements to video card and driver.

From the wiki r (archived version).

@cegaton, sorry I couldn't ask someonewithpc because it wouldn't let me.  Let me know if I'm not supposed to do that.  You're just a boss on here haha.  Would utilizing a high end graphic card under GLSL Compute give you the best results here?  Is there a difference in speed between the compute types?  Thanks guys!

@TylerDahl Yes it would. I don't have numbers, offhand, but it should.

Awesome.  Thanks for the help man! @someonewithpc


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How can I set the image to use the UV Map using the python api
I would like to bake normals (and potentially other parameters later) of an object via python code.
I came up with the following code, but it fails on the last line saying that it cannot find a valid image to bake to (I use the standard blender scene with the default cube).
I suspect this is because the image I created is not linked with the UV Map generated from the cube_project function.
How do I associate it to the image ?
Or maybe I am taking a wrong approach?
import bpy
cube = bpy.data.objects["Cube"]
bpy.context.scene.objects.active = cube

bpy.ops.object.editmode_toggle()
bpy.ops.mesh.select_all(action='SELECT')
bpy.ops.uv.cube_project()
bpy.ops.object.editmode_toggle()

image = bpy.data.images.new(name="test", width=512, height=512)

bpy.ops.object.bake_image()

Every UV face needs to be set to the image datablock:
image = bpy.data.images.new(name="test", width=512, height=512)

for uv_face in cube.data.uv_textures.active.data:
    uv_face.image = image

bpy.ops.object.bake_image()

Note that a uv_texture can't be accessed in edit-mode.
In addition to the UV face assignment, every mesh face should get a material with an image texture assigned (same image as for UV faces) and the texture coordinates be set to UV. Otherwise the texture may not show correct in viewport, although it might be baked correctly (better test!).
Have a look at the Material Utils addons, it let's you transfer UV face image assignments to material texture assignments and vice versa.


text:
Can I mirror animations on bones?
I have a model of a dragon. It's mesh was made by mirroring and also was it's bones. I want to animate a wing, but want to make the other wing to animate equally, but mirrored. Is it possible?
I'm new to blender, so I need a bit more detailed explanation.

Try copying the pose, then pasting x-mirrored= shift+Ctrl+V.
You can copy the pose in the pose menu, right next to the mode changing button.
See the one that says Pose?

Once you copy a pose (Copy Pose) you can either paste pose or paste x-flipped pose.

Sorry for my ignorance, but how/where can I copy the pose and how do I paste it?


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BGE: How to make a Key inactive after pressing another Key?
When pressing W a cube is doing a forward movement.
When I press S I want to make the W movement inactive, how do I do that?
And after by pressing W again I want the cube to do a back movement, so to do a different type of movement.

You can use states: In the first state, you have a W keyboard sensor, linked to a motion actuator that moves the object forward, and you have an S keyboard sensor linked to a "Set State" actuator, which will set the second state.
On the second state, you have a W keyboard sensor, linked to a motion actuator that moves the object backward.
That should produce the desired behavior you described.
Here's a demo, if required: logic_brick_key_remap.blend

A complementary example.blend is always welcome for newer users (not required however). On a side note, I've been meaning to tell you I loved your tutorials from a few years ago, got me more involved more with the bge :).

Thank you very much Goran! Highly appreciated! I also like you tutorials.


text:
How to load an object from another scene in the bge?
I have a game with multiple levels made up of separate scenes. I'd like to add (at runtime) objects in an "assets" scene containing some generic objects that will be used in each level.
After unsuccessfully trying bge.logic.addScene("assets") then scene.addObject("object_from_assets_scene"), I tried using a "loader" scene which would load the assets scene first (to allow for the async loading), then switch to the new scene (with scene.replace()).
Despite the scenes appearing in bge.logic.getSceneList(), none of the asset objects are in them and the main level objects aren't visible.

Is there any way to add an object from another scene?

You cannot add objects across scenes. Scenes are completely seperate. What you can do is you can use LibLoad to combine two blend files. So if you have your assets in one blend (assets.blend), you can use:  bge.logic.LibLoad(path_to_blend, 'Scene')
to merge the two scenes. If objects are on an inactive layer in assets.blend, then you can use addObject to add them when/where you want.
(note that the 'Scene' is to tell it to load whole scene, but does not tell it which. There is no way to tell LIbLoad which scene to load - it will do the one that the blend is saved with)

You can better import the same object in the scene(s) where you want to use them and just replace them into a layer you don't use in game. Like that you don't have to script anything and you can just use the edit object actuator.

Thanks for your answer :) The thing is I have quite a few scenes where these objects need to be used. If I copy them into every scene I'll have to re-copy them whenever I edit them later.. (I suppose I could link them.. but if possible I'd prefer to only store objects in a "level" scene if they are unique to that "level")

would it be a possibility to link the object datablock to the active scene?

bpy.context.scene.objects.link(obj)
  Link the object to the current scene and make it active. Optionally,
  we can make the newly created object active or selected. This code is
  the same for all kinds of objects.

from:
https://wiki.blender.org/index.php/Dev:Py/Scripts/Cookbook/Code_snippets/Three_ways_to_create_objects
i use this method to create my objects and link them to the active scene.

This question is about adding gameobjects from within the game engine. bpy is not available inside the game engine.


text:
How to constrain rigid bodies to an axis?
In the game engine there is an option to constrain rigid body translations and rotations on an axis:

Is it possible to do this with the 3D view rigid body physics system?

In blender 2.80 (and likely earlier versions), you can selectively lock translation and rotation axes, limiting physics simulations to your choosing.
Do this in the Transform sidebar (hit N to toggle).

As seen above, both X and Y axis has been locked, forcing simulation to only translate along Z-axis, but otherwise rotate freely.
This can be handy for quickly placing objects using physics. For example:

This is currently supported only in the Game Engine.
As a possible workaround, you could bake the simulation to keyframes and then remove the transform channels which you don't want.

Is this answer still valid for 2.69? I have the same question as gandalf3. The slider constraint is too complicated.

Also your alternative doesn't really work as a solution since the axis restrictions work on the solver per-frame. Disabling rotation on all three axes would prevent a ball from rolling down a hill for example.


text:
Is there a way to get a unique value per dupli group instance?
Given a number of dupligroups, is there a way to get a unique random value for each one in a cycles shader?
Using the object info node won't work, as each instance consists of multiple objects. I'd like the value to be the same for all objects in the group (in this example, the pedestals ought to be the same as the corresponding Suzanne).

Here's a demo file:

If possible, I'd like to do this without joining objects or de-instantiating the dupligroups.

I have run into this issue before, never found a solution. Was wondering again today if a solution exists. Sounds like a good feature request.

Using Particles as host for DupliGroup
Thus we can use cool feature of mesh-emitter called From Dupli. This means duplis will inherit location of corresponding space on UV map.

Create emitter mesh and unwrap all faces of emitter as separate islands (avoid overlapping in order to have unique values)
Add PS system, so amount of particles is equal to face count (disable
emit random, even distribution and set particle/face ratio to 1)
Choose Whole group as source for duplicating


text:
How to avoid subsurf distortions on cylindrical objects?
I made a cylindrical object which transitions to a squarish block. However there is some distortion at the transition:

If I add a loopcut to get a nicer surface there, it gives the cylinder a not-very-round edge:

What are some topological tricks for getting smooth subsurf without interfering with other parts of the model?

Thanks for asking this question. Ever since I can remember I've had similar problem. Haven't found the satisfactory solution yet, though :(. Maybe somebody here'll find it.

Related https://blender.stackexchange.com/questions/40788/how-to-avoid-subsurf-distortions-on-cylindrical-objects  https://blender.stackexchange.com/questions/218507/how-to-cut-or-extrude-a-cube-rectangle-from-a-cylinder-curved-surface https://blender.stackexchange.com/questions/296646/pinching-problem-with-sub-surface-modifier

Although there are several ways to do this, I would recommend selecting the outlining edges:

And then bevel them with Ctrl+B:

Odd.. For me beveling creates a tri at the corner, which causes even worse distortion: https://i.sstatic.net/JLOQ6.gif

I think you may have to bevel the cross edges afterwards.

@gandalf3 I think the key point is the extra edges where you get the distortion. You have 3 edges following the top of the cylinder where novice has one. Also adding another segment to the bevel can turn a corner tri into a quad.

@sambler I tried adding more segments, but that just subdivided the tri. I tested it with simpler geometry than in my .blend; see [this gif](https://i.sstatic.net/JLOQ6.gif. It appeared to behave the same with and without the surrounding edge loops

@gandalf3 don't do the one across at the same time, do it afterwards


text:
What exactly *is* a "closure"?
As I understand it, a "closure" is the thing passed out of those green dots on the ends of those magic black boxes known as "shaders":

I've vaguely imagined that they somehow described a sort of "probability density" of the possible directions an incoming ray could bounce towards, and maybe an albedo for each color channel
(R, G ,B).
What really makes up a "closure"?
And how can you make your own via OSL?

Inspired by this question: What can a custom cycles shader do?

In terms of OSL a closure is an expression or a function call that will be stored along with necessary contextual information... A closure is a generic holder for any type (data or functions)... Good read: http://thhube.github.io/tutorials/osl/osl.html

I think taht is another (more general) type of closure, the usual closure term of programming languages.

@RóbertLászlóPáli, yes but this is the same principle : a function (or a lexical scope more precisely) and all that this function 'knows'. It's parameters and local variables and other more global other elements (other variables or functions) it can access during it's execution.

I think I was not clear. I ment, that the closure Poor was referring to (the one that is the usual term of programming languages) is another closure, than in the question.

A closure is a computer science term for a package consisting of a function call and any other information (concrete values of arguments, etc.) needed to execute it later, AS IF in the current context.
In OSL, this is the data type of the thing that the shader network hands to the renderer to describe the properties of a surface or volume at a particular point.
You can think of it as a BSDF (although it can include other information that the shader can pass to the renderer). But the BSDF is not evaluated at the time that the shader is run -- instead, the renderer runs it later, and in fact internally there is not a single method associated with it, but rather it knows how to do a number of things, like choose sample directions, evaluate the amount of light scattering from one direction to another (with supplied with those directions), and so on.
An OSL shader can assemble a closure out of built-in "closure primitives" -- a closure may specifically be a weighted sum of the primitives -- but the actual primitives may not (currently) be authored in OSL itself. They are a part of the renderer, largely because their correct and efficient implementation seems to need to reach deeply into the guts of the renderer internals, which is precisely what OSL shaders are NOT supposed to be concerned with. Each renderer will document a number of BSDF closure primitives that it supports, which may vary from renderer to renderer. At present, there is not a strictly dictated list of which BSDF primitives you can count on in OSL, partly because BSDFs are still a hot research topic, with new and better ones getting published all the time. It doesn't seem stable enough to enshrine in the OSL language quite yet.

I think what you are asking of are the functions also called BSDFs, BRDFs, BTDFs or BSSRFs. More about these terms at this Wikipedia page. They are referred to as closures in OSL terminology, because they are implemented as closures in the programming language.

And how can you make your own via OSL?

This might help.


text:
¿How does the Blender User achieve a shortcut for Custom Operator in Pose Mode?
¿How does the Blender User achieve a shortcut for custom operator in Pose Mode?
Problem

An operator was created and is functional for the past hour or so.  A Shortcut Key was desired.  The operator name appears in [pose mode] menu Pose.  Operator use with the mouse is successful. Attempt is made to create short cut with the Add Shortcut menu depicted below. Key Binding does not appear which is a problem.  Key Binding = Shortcut in this description.
Other investigations, attempts and successes

Key binding in [object mode] is successful. Operator use is successful in menus.  Specials Menu and Python Console and Python dir command.
Key Binding attempted in [Pose Mode] creates Key Binding in [Object Mode]

The image above shows a simple operator template supplied by Blender for the text editor and then modified.
Click image to see larger original size.

Add Shortcut depicted in the image above.

User Preference image above.

Object Mode with Short Cut. Image above.

Manually employ User preferences will do the job.  Settings below.  This is not the only method.   Complications will be in a different question.


text:
Alpha transparency making wall transparent
I have a simple textured wall, and it looked really clean so I downloaded a grungy texture from CG. Unfortunately, when I tried making the alpha channel invisible, I couldn't figure it out, so I just turned the alpha under the textures panel to 0 and enabled mask transparency which I turned down to 3.14 (cause pi is cool). Its not exactly the effect I want, because some of the white from the mask still discolors the wall, but the biggest problem is once I deselect it, it turns the entire wall transparent.
Here is what it looks like while selected: almost right

but once I deselect.

What is the proper way to make the alpha channel disappear, while leaving the moldy-grunge intact and not making a gaping hole in my wall. This is a game prop.

Adding a grunge texture or decal is very easy (even easier then in cycles).
All you have to do is add a grunge or decal texture with a alpha channel under the base color,in your case the second texture slot.
Your material  and texture does not need any transparency. Both textures only influence the Color.


text:
How to render a normal map from a camera+mesh?
The best way to explain my question is actually this: https://youtu.be/B4j5tzAIflU?t=658
I am making grass the same way (on a plane) for a video game, but I don't know what the technique is called or how to use it in Blender (2.8).

Hi. Please add a full description of what you would like into the question body itself. If that link goes down or becomes unavailable, it will be unclear what this question is about.

Aaah. My bad. Lesson: Never post a thread in a hurry. I'll change the description. Thanks for notifying me.

And please upvote (or at least un-downvote) my question again, 2 downvotes probably doesn't get me any further. Thanks!

You can use Workbench and Eevee for creating any textures
For example normal and opacity image created with workbench https://youtu.be/yDJaSF4B138

I am speechless... This is exactly what I was looking for. I assume you uploaded this video, since it was posted -today- and otherwise is an insane coincidence: Thank you so much! Really. I was almost at a point starting to doubt if this technique was even used today or possible in Blender, since I only found (old) studio Max threads. I can't wait to start working on this. Thanks!

You answered a link-only question with a link-only answer. Please read Your answer is in another castle: when is an answer not an answer?

Have you seen the link provided as an answer? I couldn't wish for a better answer. Seriously. I understand the link-only stuff. Great link to the link-only QA, I agree. But 'sometimes' visuals are better to explain than words. This is such a case (because I didn't know the technical words involved). Please accept the exceptions. This is a happy and solved QA.

Blender 2.8

Properties -> Render Properties -> Render Engine = Workbench
Properties -> Render Properties -> Lighting = MatCap
Properties -> Render Properties -> Studio Light = check_normal+y.xer
Properties -> Render Properties -> Color Management -> View Transform = Standard

I also recommend:
setting the scene background to #8080ff aka RGB(0.5, 0.5, 1.0) aka HSV(0.666, 0.265, 1.0), camera to orthographic, and output to a power-of-two square render.
Note: Blender shows a "Gamma Corrected" footnote on Hex numbers and gives me this strange value: #BCBCFF instead of the expected #7f7fff or ~#8080ff, I recommend using the RGB input

Properties -> Scene -> World -> Viewport Display -> Color = RGB(0.5, 0.5, 1.0)
Active Camera -> Properties -> Camera -> Lens -> Type = Orthographic
Properties -> Output Properties -> Dimensions -> Resolution X = 1024
Properties -> Output Properties -> Dimensions -> Resolution Y = 1024

Render as usual, be sure to inspect your output closely! color management is quite fickle especially since we're not representing color data

You can compare your render to a public example normal map: https://en.wikipedia.org/wiki/Normal_mapping#/media/File:Normal_map_example_with_scene_and_result.png

Perfectly listed. THNX.


text:
How to improve this rendering so it looks more like the target image? (Disaster)
I'm trying to replicate the following image using Blender:
the image http://dl.dropboxusercontent.com/u/62862049/Screenshots/03k.png
For this, I've used MakeHuman to generate a similar-looking human, an ortographic camera and a Lattice to deform the mesh (to give that specific distorted projection). I've set the render size to 64x64 (the original image is 32x32) and used FreeStyle for outlines. I'm also using a Sun Lamp and I've deactivated anti-aliasing. This is what I got:
blender http://dl.dropboxusercontent.com/u/62862049/Screenshots/03o.png
But rendering results are terrible:
results http://dl.dropboxusercontent.com/u/62862049/Screenshots/03l.png
I have that feeling that I've done everything I could to get close to it but somehow it still fails miserably. The color is pale, the image is blurry, the outline is wrong in hands and face. I don't know what else to do.
Link to the .blend
Original 32x32 target image

When I look at his ankles in the target image, they do not seem to be proportioned like normal human ankles -- they look MUCH too thick. I suspect the creators of that figure ran into the same problems you did with trying to generate a realistic looking figure on such a small scale and compensated by not using anatomically accurate proportions.
So, if you want to try to use Blender's environment to make your figure, I would recommend finding proportions that might not look correct in the 3D Viewport or in MakeHuman, but that do look correct when rendered at 32x32.
It is also possible that the original creators did not use a 3D model rendered at 32x32, but rather just painted the image by hand, pixel by pixel, or perhaps used some process other than rendering from a 3D environment.
Another possibility is to render your figure at a much higher resolution so you get all the details you want, and then shrink it down & selectively edit it in Photoshop.

Hello, thanks. The original image is hand drawn, our team is trying to replicate it using models to generate a huge amount of combinatoric sprites (unfeasible to touch manually). I'll be trying to deform the mesh to look better after rendering, but I'm mainly worried with the colors and lack of details in the image. I've improved to this, but it still looks really blurry and pale.

I suggest heavily evagerating the colors, and also exagerating the sharpness and size of the features. In fact, you might even consider making your own human figure out of cubes -- each cube to represent one pixel in your final render. That might help you get MUCH clearer, sharper features and also help you see much more clearly which faces, edges and vertices need to be edited in order to get the desired result.


text:
Setting parent to armature with automatic weights deforms the mesh
I'm following this rigging tutorial. Everything worked perfectly until 10:40, where the uploader asks to set parent with automatic weights. This completely deforms the mesh, as shown below.
aa http://dl.dropboxusercontent.com/u/62862049/Screenshots/023.png
bb http://dl.dropboxusercontent.com/u/62862049/Screenshots/024.png
What is wrong?
Link for the .blend

Can you put a download link of your blender project?

@lucblender updated.

First of all try to align your bone. It can help a lot for a better rig. For doing that follow this step : show the axes of your bones, enter in the edit mode of your rig and align your bone with the roll property on the right pannel of the 3D view. You can see an exemple in the screen below!
Now you can do your automatic weight.
I looked a bit on your rig and apparently you played a bit with it. You have to reset all the roation of your bone in pose mode.
Go in pose mode, select all bones with a and types alt+r.
And now you have to play a bit with the pole angle of your IK modifier for align all your bone.
Normally with this 3 tips your armature has a better set up.

Instead of doing all that difficult stuff other mentioned, just make sure your armature in edit mode is absolutely symmetrical. I'm not sure why, but sometimes when mirroring, armature gets rotated slightly which messes up all further actions so you shouldnt "mirror" armature with shift+d -> s -> x -> -1 instead use mirror by axis (not really sure but its alt+m -> axis or smth similar)

I watched the same Tutorial ( https://www.youtube.com/watch?v=cGvalWG8HBU&index=54&list=WL ) and spent days and many hours trying to figure the same problem out. I am a noob and this was my first rigging so that didn't help either. What fixed the deformation for me was making sure the joints (Elbow, Knee etc.) were bent (even slightly) in the direction they are intended to bend. When you parent the mesh to the bones with automatic weights or any other way with the pole targets set the mesh deforms. This deformation does not happen until the pole target is set though. In that tutorial they are set before the parenting of the mesh. This is because blender (I don't why) turns them off target which twists the mesh in the direction blender turned them. You correct this by changing the pole angle in the bone constraint menu to the correct position. This lines up the mesh and the joint. The mesh is twisted back to its correct position and the joint bends in the correct direction. Now if the bones are straight (my problem) or bent in the wrong direction no matter what you do (line up the bones axis or try to correct the pole angle) the mesh will not be corrected (not deformed) if the joint is in the correct position. Even if you have everything already set up ( mesh parented to the bones, the IK constraints, etc.) you can go into edit mode, position the joints in the correct direction by clicking on the ball between the bones where the joint bends and move them into he correct direction. Go into pose mode click on the bone that has the IK constraint go to the property panel click on the bone constraint tab (little bone with the chain) and change the pole angle till the mesh is perfect. You can hit the tab button to go back and forth from edit mode and pose mode to see if you have lined up the mesh correctly with the pole angle.

I know this post is coming in a bit late, but if anyone else stumbles upon this issues and is looking for a solution and they happen to be making a character for a game this post might help. I was creating a character to put within UE4(Unreal Engine 4) and I continued to get the same issues that these gentlemen were getting. But you cannot upload a character mesh into UE4 with the IK bones, or the knee and elbow bones. So if you go ahead and un-parent the armature from the mesh and delete these outer bones and then re-parents the armature to the mesh I found that I had no issues with the twisting and turning on my character. All the bones bend perfectly with no clipping issues. Hope this helps someone!

Thanks, Helms.


text:
How to toggle Render Region between camera bounds and marquee-selection?
The Problem
Like many people, I use Render Region to lighten the load on viewport rendering by only rendering what's visible to the camera.

I also use Set Render Region (CtrlB) when I want to focus on just one specific area, and since all the samples get spent rendering that area, I can see that specific area more quickly.
The problem is that if you use Set Render Region and draw out a marquee selection, and then after that you want to resize the render region back to the camera bounds, you must Clear Render Region (CtrlAltB) and then re-enable Render Region by ticking the checkbox.
An animated GIF to illustrate the issue simply:

The Question
Is there a way to re-map CtrlAltB to toggle between the marquee-selected region and the camera boundary region?
More Details
Examining the Info window, we can see that the syntax for enabling Render Region is bpy.context.scene.render.use_border = True
On the other hand, Set Render Region is bpy.ops.view3d.render_border(xmin=682, xmax=786, ymin=1248, ymax=1422)
And Clear Render Region is bpy.ops.view3d.clear_render_border()
Even though all three of these operations define the region to be rendered, they work differently. I have not found a way to toggle between two differently sized render regions (user-specified and camera bounds).

'Render Region' Toggle
You can implement a custom Operator to toggle Render Region using a shortcut. In this case, all you'd have to do is finding a reliable way to set the state of RenderSettings.use_border:

The following demo based on the answers of How to easily toggle a Boolean property?
and Create keyboard shortcut for an operator using python?:
toggle-render-region.py
# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####
# <pep8 compliant>

import bpy

bl_info = {
    "name": "Toggle Render Region Hotkey",
    "author": "brockmann",
    "version": (0, 1),
    "blender" : (2, 80, 0),
    "location": "3D View",
    "category": "3D View"
}

class RR_OT_toggleRenderRegion(bpy.types.Operator):
    """Toggle Render Region in 3D View"""
    bl_idname = "view3d.toggle_render_region"
    bl_label = "Toggle Render Region"
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self, context):
        context.scene.render.use_border ^= 1
        return {'FINISHED'}

addon_keymaps = []

def register():
    bpy.utils.register_class(RR_OT_toggleRenderRegion)
    addon_keymaps.clear()

    # handle the keymap
    wm = bpy.context.window_manager
    kc = wm.keyconfigs.addon
    if kc:
        km = wm.keyconfigs.addon.keymaps.new(name='3D View', space_type='VIEW_3D')
        #kmi = km.keymap_items.new(RR_OT_disableRenderRegion.bl_idname, type='B', value='PRESS', ctrl=True, shift=True)
        kmi = km.keymap_items.new(RR_OT_toggleRenderRegion.bl_idname, type='B', value='PRESS', ctrl=True, alt=True)
        addon_keymaps.append((km, kmi))

def unregister():
    bpy.utils.unregister_class(RR_OT_toggleRenderRegion)

    for km, kmi in addon_keymaps:
        km.keymap_items.remove(kmi)
    addon_keymaps.clear()

if __name__ == "__main__":
    register()

As mentioned by @batFINGER in the comments there is also a generic bpy.ops.wm.context_toggle() operator for convenience which allows to toggle any BoolProperty (also used for some of the default hotkeys in Blender).
toggle-render-region.py
 # ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####
# <pep8 compliant>

import bpy

bl_info = {
    "name": "Toggle Render Region Hotkey",
    "author": "brockmann, batFINGER",
    "version": (0, 1),
    "blender" : (2, 80, 0),
    "location": "3D View",
    "category": "3D View"
}

addon_keymaps = []

def register():
    addon_keymaps.clear()

    # handle the keymap
    wm = bpy.context.window_manager
    kc = wm.keyconfigs.addon
    if kc:
        km = wm.keyconfigs.addon.keymaps.new(name='3D View', space_type='VIEW_3D')
        kmi = km.keymap_items.new("wm.context_toggle", type='B', value='PRESS', ctrl=True, alt=True)
        kmi.properties.data_path = "scene.render.use_border"
        addon_keymaps.append((km, kmi))

def unregister():
    for km, kmi in addon_keymaps:
        km.keymap_items.remove(kmi)
    addon_keymaps.clear()

if __name__ == "__main__":
    register()

If you'd like to edit the old shortcut manually without using an add-on, replace the identifier and the data_path for the old hotkey by wm.context_toggle and scene.render.use_border:

Toggle between 'Selection' and 'Camera Bounds'
If you'd like to toggle between the current selection and the camera bounds using a shortcut you'd have to implement a custom Operator as well as supplying a new scene property in order to store the coordinates and restore them if necessary:

custom-render-region.py
# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####
# <pep8 compliant>

import bpy

bl_info = {
    "name": "Custom Render Region",
    "author": "brockmann",
    "version": (0, 1),
    "blender" : (2, 80, 0),
    "location": "3D View",
    "category": "3D View"
}

class RR_OT_customRenderRegion(bpy.types.Operator):
    """Custom Render Region"""
    bl_idname = "view3d.custom_render_region"
    bl_label = "Custom Render Region"
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self, context):
        scene = context.scene
        rnd = scene.render

        if rnd.border_min_x != 0 or rnd.border_min_y != 0 or \
            rnd.border_max_x != 1 or rnd.border_max_y != 1:
            # Store the values
            scene.custom_render_bounds = (
                    rnd.border_min_x,
                    rnd.border_min_y,
                    rnd.border_max_x,
                    rnd.border_max_y)
            # Camera bounds
            rnd.border_min_x = rnd.border_min_y = 0
            rnd.border_max_x = rnd.border_max_y = 1

        else:
            # Set the values
            rnd.border_min_x = scene.custom_render_bounds[0]
            rnd.border_min_y = scene.custom_render_bounds[1]
            rnd.border_max_x = scene.custom_render_bounds[2]
            rnd.border_max_y = scene.custom_render_bounds[3]

        # Clear region if not in camera view
        if not context.space_data.region_3d.view_perspective == 'CAMERA':
            bpy.ops.view3d.clear_render_border()

        return {'FINISHED'}

addon_keymaps = []

def register():
    bpy.types.Scene.custom_render_bounds = bpy.props.FloatVectorProperty(size=4)
    bpy.utils.register_class(RR_OT_customRenderRegion)
    addon_keymaps.clear()

    # handle the keymap
    wm = bpy.context.window_manager
    kc = wm.keyconfigs.addon
    if kc:
        km = wm.keyconfigs.addon.keymaps.new(name='3D View', space_type='VIEW_3D')
        kmi = km.keymap_items.new(
            RR_OT_customRenderRegion.bl_idname, type='B',
            value='PRESS',
            ctrl=True,
            alt=True)
        addon_keymaps.append((km, kmi))

def unregister():
    bpy.utils.unregister_class(RR_OT_customRenderRegion)

    for km, kmi in addon_keymaps:
        km.keymap_items.remove(kmi)
    addon_keymaps.clear()

if __name__ == "__main__":
    register()


text:
How do I "un-roll" the viewport?
Lets say that I've rolled the view port with ⎈ Ctrl⇧ Shift Scrollwheel, and now want to get it back to its original orientation. How do I do that?

Hit Numpad 7,3 or 1. When you navigate out of the view, it will be reset.

This only works until you select the next object with / which will roll the camera of the view port again.


text:
Can freestyle render edges with no face?
I have a mesh with some "faceless edges". Can freestyle render them?

Nope, I don't think this is supported. See http://blender.stackexchange.com/q/3149/599 for alternatives.

Noooooo! My life has just become painful.

@gandalf3 Your answer is correct, do post it as an actual answer so it can be marked as such! (And generally please avoid answering questions through comments ;))

@SimonRepp lol, normally I'm the one asking someone to post their comment as an answer.. :P Thanks, answered :)

yes you can, here I've posted a simple workaround.

Unfortunately this isn't supported (yet):

Known Limitations and issues

FreeStyle is only available for the Blender Internal renderer.
Highly memory demanding: All mesh objects in a render layer are loaded at once.
Only faced mesh objects are supported. The following kinds of meshes are ignored.

Mesh faces with wire materials.
Mesh faces with completely transparent materials.

Transparent faces are treated as opaque faces.
No edges at face intersections are detected yet.
Layer masks do not work with Freestyle.
Freestyle rendering results do not have any Z depth information.
Does not work with a panoramic camera.

Emphasis mine. Note that Freestyle is available in the latest development builds and will be in 2.72.
Perhaps it will be supported someday, but for now you'll have to try something else. See How can I render an edge only mesh as solid lines? for alternatives.


text:
What are the available attributes in the attribute node?
What are All the attributes I can access through the attribute node. I know of a few like density, flame, a UV map etc, but I'm curious as to what else there is.

Custom properties are not accessible D:

The wiki says that internal attributes are also available. Those include, but are not limited to, N (normal), P (position) and Ng (Geometry Normal)

@gandalf3 I even looked.... I can't believe I missed that.


text:
How to roll the viewport?
How do I rotate the viewport around the local (to the view port) - Z axis?
Basically what you would  get if you were to hit R with the camera selected in camera view.

You can press ⎈ Ctrl⇧ Shift ScrollWheel, or ⇧ ShiftNumpad 4 and ⇧ ShiftNumpad 6.

Currently the scrollwheel binding doesn't exist in 2.8, however you can add it back yourself. Under User Preferences > Input > 3D View > 3D View (Global), press Add New and set the operator to view3d.view_roll. Create a binding for both left and right:

Re: @squarespiral's comment on the other answer, you can refine the roll increment on either/both of these methods by going (in Blender 2.79 anyway) to User Preferences > Input > 3D View > 3D View (Global), scrolling down to the block of "View Roll" settings, clicking on the "expand" triangle of the one you want to change, selecting "Roll Angle" from the dropdown on the bottom right, and then typing a Roll Angle in the input box on the left (in radians, I think; I find a setting of -0.02 for Ctrl-Shift-ScrollWheelUp and 0.02 for down works really nicely for fine tuning with the mouse wheel).

Ctrl+Shift+ScrollWheel apparently does not work (anymore) in Blender 2.80 beta, found no replacement either. The other two shortcuts work fine though.

@SimonRepp It works for me on latest master (1c5860407068)

@gandalf3 Are the beta builds on the website based on master? If yes I'll gladly try with the next release then :) Thanks for the info!

@SimonRepp I believe they are. However, I just remembered that I actually re-added the bindings myself (if I load factory settings it no longer works). I'll update my answer.

For those in 2.831+ the accurate location is Preferences > Keymap >3d View > 3D View(Global) ; the chain in the answer does not exist (Input has no sub of 3D View as it is now in Keymap). Let me know if I've misunderstood, but this works for me.

One non optimal method is to bring the camera to the viewport(Ctrl-Alt-Numberpad 0), select the camera and hit R. This isn't the neatest method, but it still works. It also offers to the degree precision. once positioned, you can delete the camera if it bugs you. see this question on how to "un-roll" the viewport once you're done.

For higher rotation precision this is better than the accepted answer - with Shift you have pretty good control.

Blender 3.5
I wasn't able to expose the RNA controls in a new keymap, so instead, I changed the existing NDOF "View Roll" keymaps.  There is one for ClockWise and one for CounterClockWise.
Keymaps: 3D View: View Roll
Set to Mouse
WheelDown  (WheelUp for CCW)
Shift & Ctrl  (or your preference)
Roll: 0.2  (-0.2 for CCW)
https://prnt.sc/J5gwBDDsM6Xp


text:
Keyframe not animating bone from initial position?
I'm new to blender and even newer to animation.
I was working on animating my enemy model for the game I'm developing and everything went fine with the right leg.
However, when I went to edit the left leg, I discovered that it wasn't being saved in the keyframe for some reason and instead was edited so every frame has the left leg in the air.
The record button is on but nothing seems to be making it move into the air. The right leg edits without a hitch.
Frame 20:

Frame 40:

Any idea why this could be happening?

Maybe you accidentally create a constraint in the left leg's bone? Copy Transform, Limit Location or any other that might restrict its movement? Without any screenshot, this is a vague question...

@adhi I can't post a screen cap because of my reputation (i'm new :/ ) I'm hoping I can post a link to a download of the pics http://www.mediafire.com/?k463a75a0g2014v

@adhi i think it worked lol. If you see them, you'll see that the leg remains in the air regardless of the frame i'm on.

You need to set an initial keyframe for any animated data, including armature bones, in the first frame. The pelvis left bone is set to that position at frame 40, but because there's no keyframe before it, its position is interpolated all the way to the starting frame.


text:
What's Wrong with Quaternion Rotation in the Game Engine?
Steps:

I created two identical objects, and animated them to rotate 360 degrees.
I used euler for the first object and quaternion for the second.
In the Viewport they rotate the same, but in the Game engine
the second object is rotated differently.

What's wrong with quaternion rotation in the Game engine?
blendfile

Link to .blend seems to be broken.

Try CTRL-A > Apply rotation

related: http://blender.stackexchange.com/questions/2988/cant-update-remove-keyframe-values-from-an-imported-collada-file

It depends on how you animated them, and it's difficult to tell with the broken .blend file. Euler angles and quaternion angles have different parameterizations, and I'm pretty sure however you're animating the rotation doesn't account for the difference: http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles

@OrelGenya can you reproduce this in a new blend file? If so, please report a bug .

@brita_ I can reproduce this with a new .blend in the 2.72 RC. There seem to be some existing reports too: https://developer.blender.org/T38892 and https://developer.blender.org/T28853

@gandalf3 I took a quick look, BGE indeed only supports the default euler rotations. The animation curves in BGE are Moguri's area, he is already assigned to that last bug.. so

This issue seems to be an unsupported feature at the moment. Can someone mark this question as answered. Brita wrote: @gandalf3 I took a quick look, BGE indeed only supports the default euler rotations. The animation curves in BGE are Moguri's area, he is already assigned to that last bug.. so – brita_ Oct 2 '14 at 8:00

From Hawkenfox:
"This issue seems to be an unsupported feature at the moment. Can someone mark this question as answered?"
(Okay - I am posting this answer, pasted from your comment, for the purpose of marking this as an answer and closing the question. Please mark as answered.)
Brita wrote: "@gandalf3 I took a quick look, BGE indeed only supports the default euler rotations. The animation curves in BGE are Moguri's area, he is already assigned to that last bug.. so" – brita_ Oct 2 '14 at 8:00 – hawkenfox Dec 26 '15 at 3:10
BTW, was this resolved?