text:
Cycles outline objects
I want to add the outline effect in all, not only border.
How and can do this in Cycles fast?
I've searched for many pages, but all the methods did not work because I did something wrong.

Possible duplicate of How to get silhouette with contour rendering in Cycles

Consider using freestyle.  Please search freestyle. There are many video tutorials on freestyle. Then show your work.  You may want to use freestyle with Blender Render to reduce time during your learning experience.  You can use the compositor to combine lines with a regular rendered image.
Also you can use the compositor put lines around objects all by itself.  The line can be a glow.  This is possible because Blender can reveal contrast between a transparent background or object id and the surrounding image.

Freestyle only work good for me, if I set  175 -180 degrees edge detection in options, but blender drawing triangles not squares. In mesh I have squares. I add image.

For rendering the triangulation like that, you could use the Wireframe node (input>>Wireframe).

For rendering squared faces, it's better to use a square texture with an outline, and use a resetted UVmap.


text:
Modifiers array and curve
I have curve and plane with modifiers array and curve. I can not get the exact plane guide on the curve, sharp verticles. Anyone help?

Instead of array and curve on a plane, you could use a "straight" simple curve as a bevel object of your main curve, as shown below:

to animate the "shape" to follow the "curve", with all straight angles, you could just animate the start/end bevel factors, es:

subdividing the "path" curve more, in particular near the corners, will give more control on how the tip/end of the shape will follow it.

But if I want after make animation in this array and mesh then i can't?

? I didn't get exactly how you want to animate this shape, later. Of course you can animate all of both curves settings, or you could of course convert the resulting shape above, made of curves, to a mesh and then animate that somehow, but it could depend on what you need to do...

I mean snake animation for curve

since you had a curve even with the array/curve modifiers, how did you try to animate the "snake" before? the issue with the shape not following exactly the sharp corners could be a different one...? If yes, ask another question on that specific topic: it would be what this site requires, and you also would get much better answers or hints...

I make curve. I apply location. then i make plane and add modifiers array, curve in this plane. I clear location. In modifier curve i choose first curve, and animate array.

do you mean something like this https://blender.stackexchange.com/questions/68590/how-do-i-create-a-self-drawing-2d-shape ?

Yes, but I want the mesh to be guided exactly on the curve

I added an example above. But maybe adding another question asking how to animate that curve as you wish (maybe adding some reference would also help)

I have another problem for flexures curves, as in the picture above

Ok, i solved. I choose handles type as vector

I have last question in this problem. Did i can change Bevel factor is all OK, curve is animated, but i want change end of curve, that not to be as spicy. Is possible?

...as spicy? what do you mean?

A curve can also get a flat surface without a second curve object, increase the extrude value. Similarly, the bevel, resolution and fill type work together to get a full or part tube result.

source: Stack Exchange

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

sort: votes


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Animation Nodes Loop Issue
I'm having this issue with animation nodes where, if I want to change the list of vertex positions of an object based on a boolean condition, then only one vertex gets affected. In this case, only the vertex at (1,1,0) gets moved upwards. In the example I appended, clearly all vertices of my object are at a lesser distance than 10, so they should all move. However, if I delete the "boolean branch" of the tree, and modify the whole list blindly, the whole object moves.
Thanks!

EDIT:
I'll append a screenshot of the actual nodetree where I'm having the issue. As you can see I'm looking for the nearest five particles of the particle system to the point, and then, with a very simple script, i find the velocities of those particles and calculate the resultin vector. Also, I check if the minimum distance of the five is less than some arbitrary number that I choose, and based on that, I decide to do the change or not. Appart from that, I check for the nearest points in the sphere to the current vertex in the iteration (and append the index of said vertex as well to the list of indices). Then I use a script which I will leave here to change all the vertices that are pointed to by those indices in the original list of vertex positions. And based on the boolean mentioned before, I choose what list to connect to the mesh output node.
What I intend this to do is, for every frame in the animation, change the whole list of vertex positions based on everything I just said.
Thanks for the help!
Script:
def mod_vec_list (ind, pos, vec_dist, vec_vel):
    for x in ind:
        cust_dist = (vec_dist - pos[x]).length + 1
        pos[x] += (1/cust_dist) * vec_vel
    return pos

res = mod_vec_list (ind, pos, vec_dist, vec_vel)

There are three reasons why your node tree don't work as you expect it to. The following three sections explain those reasons in details.
Data Copying
First, please read the Data Copying section in the documentation to understand what we are talking about. You expect all the vertices to move one unit upward, your reasoning is that the condition is always True and this is true. However, notice that your If True input is connected to a Set List Element node that, in turn, is connected to a parameter of the loop. Since that parameter is connected to the If False input of the Switch node, enforced data copying is performed, subsequently, the Set List Element doesn't edit the list, but rather a copy of the list that is only available is the scope of each iteration. By the end of the loop, you never moved any vertices, you moved only one vertex in each iteration in its scope. Cut the connection going to the If False input and you will see the loop works as expected, that's because data is no longer being copied, that is why when deleting the condition branch, everything works as expected.
Instant Overwrite
You are outputting the vertices to the mesh at each iteration and each iteration overwrite the vertices location that was written in the previous iteration, so, the only effective data written is that of the last iteration simply because it will not be overwritten. In that last iteration, the If True input is the original vertices except for the last vertex moved upward one unit which you observed as that at the location (1,1,0), the reason for this is what which we described in the foregoing section. In conclusion, never write data inside a loop! Output the data from the loop then write it.
Infinite Offset
You are getting the vertices locations from the Cube and outputting it to the Cube, upon continuous execution of the node tree, the vertices will start to move to infinity, which, I assume, is not something you want. In conclusion, your source shouldn't be your output, either cache the vertices location or output to a new mesh.

Thanks, but that's not the issue. I was evaluating the socket, I just disabled the button when I did the screenshot. Morover, I tried your method, and I run into a different problem which is that my subprogram outputs all the lists resulted from all the iterations, concatenated, thus the vertex count does not match.

I was doing something wrong, your method does give me what I want, but it still confuses me why the first did not work

In my real problem, though, I don't see how this is viable, since I have a custom script that modifies several elements of the list in one iteration, and this is crucial, any help would be appreciated

@nachosanchez Can you add more information regarding the real problem?

Thanks. In my real problem, I have a small sphere, which is a particle emitter, and a big one, which is a collision object. What I'm trying to do is to make the particles sort of deform the outer sphere once they collide with it, but in a very subtle way. So to emulate this I have a boolean condition related to the particles distance to the current vertex in the iteration. Now, I don't want to modify just that vertex since it would be too abrupt. So what I did was create a simple script that modifies some other vertices nearby and makes the deformation smoother.

This is why I'm outputing a whole list. In my head it is simple. If this is true, give me that list, if not, give me the original, and do not make changes. However as soon as I introduce the switch node, everything breaks, and as stated before only one vertex gets affected

@nachosanchez Ok, I think I know what you want to do. Your original node tree is rather ineffective, the vector list parameter is copied because it is connected to two sockets, subsequently, set list element node is rendered ineffective for anything out of the scope of the current iteration. Moreover, the location of the vertices is not affected by any iteration except for the last one.Here is what you should do, edit your question to be more specific so that we can answer it here, then ask another question describing the effect you want to achieve, including what you already tried.

Ok, I just edited the OP. I hope it gives you some more info on the issue. Also, could you elaborate a bit on the vector list parameter being copied (how it gets copied specifically), and why that makes the last iteration to be the only one to have effect? Thanks so much.

@nachosanchez The explanation as to why this doesn't works require some time, so if you don't mind, I will write a comprehensive answer tomorrow morning.

@nachosanchez Just added the answer, I only answered your original question. If you have further inquiry related to your edit, please ask it in another question and remove the edit from this question.

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


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Motion tracking round objects
I'm kind of new to motion tracking, and I need some help. I'm trying to replace the face on some footage of a LEGO minifigure. (You can see the footage in the GIF below):
So, I added tracking markers to the eyes and mouth of my minifigure, and tracked them. When I go to Reconstruction>Link Empty to Track, it makes empties in my 3D view. They look fine from the camera angle, but in 3D space, all of the empties are lined up throughout the entire frame sequence, they just wobble around instead of move in 3D space.

Since they don't move in 3D space, my new 3D face I am trying to add will not rotate with the head, instead, it just sticks there.

So, my question is, what do I need to do to do this? The face needs to rotate. The backface culling will take care of the other side of it so it isn't seen, but my tracking markers are not moving correctly, so it ruins the entire thing.
Thanks for the help in advance! =D

@poor I wasn't looking for a tutorial, I just haven't had any time to try out your answer yet to see if it works. It looks like it will, though. Thanks for it, I will vote it up, and try to test it out this afternoon. :)

As cegaton mentioned your current solution does not represent 3d space, because you don't have enough trackers. You can try the following workflow:

First enable object tracking

Try to track the head with 8-14 markers
Increase the search area of the markers, if the footage is jumpy
Solve your object track with a value bellow 0.6
Apply a camera solver constraint to the scene camera without solving it, this  should show your object solution (calculated empties) in the viewport

Align your new face geometry to the empties (trackers) or use the trackers to pointcloud function to reconstruct the head
Apply an object solver constraint to the new geometry

Now your object hopefully should move properly with the empties.

Thank you! I made some new footage with more tracking points, and tried your method and it worked. I had a minor issue with the face going rotating the opposite way, but I think I've figured that out.

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


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What are the benefits to using procedural textures VS image textures?
I have been seeing a lot of cool tutorials for procedural textures in Cycles lately, but I was wondering, are procedural textures actually more efficient rendering-wise than image textures? Do they help speed up the render, or would image textures be a better choice? What are the benefits to procedural textures?

Go procedural! But seriously, this is primarily opinion based, so it might get closed unless there are some objective things (i.e. the fact that GPU's won't flood their texture memory)

I think you could rephrase this question into ' what are the benefits of using Procedural vs Texture based materials'  and you will get less opinion and more useful fact. As it stands this is going to invite some close requests, probably.

Procedural textures use less memory, have infinite resolution, don't require UV mapping, but require more effort to get a photo-realistic look.

Theoretically, a procedural texture is better, in the same way a vector graphic is better than a raster image. It has infinite resolution, can cover any surface, doesn't require UV mapping, and can be created without getting off your chair or browsing on the web.
However, an image texture has advantages too. Sometimes a scene, using image textures, can be finished in under an hour, vs a procedural workflow might take days. Image textures also, if sourced from a photograph, can have natural and realistic qualities a procedural textures might not (unless the procedural texture is really really really good).
In list form:
Procedural Textures Pros:

Infinite resolution
Increased editability
Can be applied to nearly any model without repetition or resolution issues.

Image Textures Pros:

Fast to create download.
Good-looking results easily achieved

Well put. I would add a reminder to all that it doesn't need to be either/or. We can make hybrid materials that incorporate texture elements as well as procedural elements and use the merits of each. For example, an image may look repetitively tiled on its own, but if combined with procedural noise that can give enough variation that it appears natural. Or conversely, a procedural-only material may be looking too computer-generated on its own, but once complex color elements from a photo texture are introduced it becomes believable.

When you say "fast" on image textures, do you mean rendering or creation? I understand that it's possible to find an image fairly easily, while creating a procedural of something similar would take a lot of time, but what about rendering?

I mean't creation time.... as far as rendering goes, I can image some procedural textures using more CPU power but less memory, while image textures may use more memory and less CPU power, but I'm not sure. I think overall, procedural textures would be better for performance, due to the memory advantage, which is the big one with rendering.

Seems image textures are faster, caveat, only if its worth the bake time
https://www.blendernation.com/2020/03/29/reducing-render-times-by-40-with-texture-baking/
the above link basically says that images render faster than procedural textures because computing effort. BUT, baking procedural textures can take a long time, so its a judgement call on which is ultimately faster.
e.g. a 2 second clip with an insanely complicated node setup is prolly not worth baking.
but a 15 min clip with the same setup might be worth the bake time

Hi and welcome :)  Link only answers are generally discouraged here, as links over time tend to disappear on the web. Please consider expanding your answer, and adding the essential information from the link so that it is available to future users of the site. Thanks.

From personal experience... From a client's side on a video game, procedural texturing works very well very fast in multiplayer games and mmo's as long as as your spaghetti is no more than 2 or 3 layers of rather small operations, so it is suitable and best used  for low polygonal count meshes  so you will see them a lot in non realistic games where the shading can be simple and a lot of render time saved with simple shader setups ( not the spaghetti bowl kind with 128 nodes). Now when it comes to baking your nodes individually for each channel and then hooking them up to a bsdf is sort of like the happy medium, but you lose a bit of that easiness to scale with simple mapping node to fit your model just right but you still have that sorta quickness that comes from having to load each separate channel in a small file and map it to faces/(insert preferred image  file ext png/jpeg.)... and then map them per face( these are all things your gpu gotta go through to display what you told it to) so at the end of the day, the happy medium is best. That is where you use compressed pic of real life object normals that carry that grain you want plcuk them into a principled BSDF and then go all out on pasta code for the channels you want to run your texture through, the next step is to first cook every snipped of every channel...combine shader those and cook it again and then pluck that where it goes...you know the PBR workflow its really the best happy medium when what you are building is going to be used for games or for low poly projects and stuff. At the end of the day if perfection and realism is what you want then you gotta go photo mode man...and you have to be one of those guys and can see some patter in some random object in nature and have an idea of a bunch of things you can do with that one patter by just tweaking it. that is where photo quality really lies. when you go out there in the world take an actual picture of something, separate all its channels and then do with them what you want. TO NOT BORE YOU MUCH MORE... for work on games, indy project, low poly projects...pasta shaders, for your portfolio , your nice renders your scenes, PBR's. and then for that hollywood quality stuf.minimum 8k photorealistic plus pbr plus volumetrics and lights... LIGHTS LIGHTS LIGHTS. ive seen guys with awesome model with epic shaders turned to S** renders because lights where bad or not enough or too much or placed wrorng or the wrong kind.

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


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Set rotation values without applying them
Is it possible to set some rotation values to Blender GUI corresponding object fields (or any other like location or scale) without actually applying them to the object itself, like some sort of "offset"?
I mean I have script that set some objects to scene, rotate them right but writes its values as (0,0,0) instead of their real rotation values (but I know those real values myself so I could set them BUT without changing object actual rotation)...like let's say object rotation value is 0 but I want to be represented and set visually in Blender rotation fields as 90 - is something like this possible, please?
P.S.: I NEED SCRIPT BASED ANSWERS ONLY

You could try something like setting the rotation to -180 (and actually rotating the object), applying it (setting rotation to zero without affecting the object), then rotating by 90.

actually that was exactly what I was intended to do right from the first time but the problem is that the code is really quite complicated dealing with mathutils Matrix so it cannot be done easily like that simply because it is really problem to understand the code in its complexity...so I really need to know if what I am asking is possible at all

@gandalf3 actually as I play more with the code now I see what you meant by APPLY and it could work, that was part I was missing in my concept ;) gonna play more with ot and then let you know...

@gandalf3 yea, your solution with APPLYING CHANGES making values offset-like finaly works after some time of tweaking and changing things around, thanx a lot for the suggestion my friend! ;)

Could you post your answer in the Answers box so this question can be marked as "answered"?

Related: http://blender.stackexchange.com/q/8892/599

Here's a script which does this, comments inline.
import bpy
import math

#target rotation:
target_rotation = [90, 90, 90]
#object to operate on (active object):
ob = bpy.context.active_object

#this assumes you are starting at 0 rotaton, so you pobably want to apply rotation before doing anything:
bpy.ops.object.transform_apply(location=False, rotation=True, scale=False) #apply rotation
#get inverse of rotation we want:
t_rot = (math.radians(target_rotation[0]*-1),
         math.radians(target_rotation[1]*-1),
         math.radians(target_rotation[2]*-1))
#we need to apply the rotations in reverse order, so unsure that we are in zyx:
ob.rotation_mode = 'ZYX'
ob.rotation_euler = (t_rot) #set rotation to inverse
bpy.ops.object.transform_apply(location=False, rotation=True, scale=False) #apply rotation

t_rot = (math.radians(target_rotation[0]),
         math.radians(target_rotation[1]),
         math.radians(target_rotation[2]))
ob.rotation_mode = 'XYZ' #set rotation mode back (was zyx, so we want xyz)
ob.rotation_euler = (t_rot) #set rotation

Pardon my probably poor python ;)

I was searching for this whole evening... thanks :)

The script gandalf3 provided works great for me. Is there a way to apply this to all selected objects in a hierarchy? When I select a hierarchy and run this script, only the object at the top of the hierarchy gets updated.

Just for completeness sake
So gandalf3 provided a beautiful answer applying the difference.
If however, you want to actually change the values, and only fake differing values in the user interface, you can overwrite the interface instead.
The idea is to display custom properties instead of the ones usually found.
The custom properties can then in turn set, get and modify the true values according to your likings.
This here is a much simplified example overwriting the render-panel.
class Render_panel_override(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Render"
    bl_idname = "RENDER_PT_render" # <== we assume the same bl-id that the original panel has
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "render"

    def draw(self, context):
        layout = self.layout
        obj = context.scene.objects.active

        layout.row().label(text="Hello world!", icon='WORLD_DATA')
        layout.row().label(text="Active object is: " + obj.name)
        layout.row().prop(obj, "name")
        layout.row().operator("mesh.primitive_cube_add")

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

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

You could try something like setting the rotation to -180 (and actually rotating the object), applying it (setting rotation to zero without affecting the object), then rotating by 90. –  correct answer provided by gandalf3

Note: This anwser is based on gandalf3 correct solution and is related to @skuwid comment in the gandalf3 anwser comments
Here is what I created based on gandalf3 answer to iterate through all selected objects:
import bpy
import math

# Target rotation:
target_rotation = [90, 90, 90]

# Objects to operate on (all selected objects):
selected_objects = bpy.context.selected_objects

# Loop through all selected objects
for ob in selected_objects:
    # Deselect all objects first to avoid any overlap
    bpy.ops.object.select_all(action='DESELECT')

    # Select the current object and make it active
    ob.select_set(True)
    bpy.context.view_layer.objects.active = ob

    # Apply current rotation to zero out before applying new rotation
    # Using isolate_users here is optional - in my case I had to use it because children of my objects have been using Multi User Data which dissallowed applying transform
    bpy.ops.object.transform_apply(location=False, rotation=True, scale=False, isolate_users = True)

    # Get inverse of the rotation we want
    t_rot = (math.radians(target_rotation[0] * -1),
         math.radians(target_rotation[1] * -1),
         math.radians(target_rotation[2] * -1))

    # Set rotation mode and apply the inverse rotation in ZYX order
    ob.rotation_mode = 'ZYX'
    ob.rotation_euler = t_rot  # Set rotation to inverse
    bpy.ops.object.transform_apply(location=False, rotation=True, scale=False)

    # Now apply the actual target rotation
    t_rot = (math.radians(target_rotation[0]),
         math.radians(target_rotation[1]),
         math.radians(target_rotation[2]))

    ob.rotation_mode = 'XYZ'  # Set rotation mode back to XYZ
    ob.rotation_euler = t_rot  # Set rotation

    # Deselect the current object before moving to the next one
    ob.select_set(False)

I'm also not using blender and python very often so beware of any mistakes I may have accidentally put there ;)

How does this help the OP?

@Joachim user skuwid in the replies to gandalf3 anwser has asked for a version of the script that works for all selected objects. Since I did that I figured i might post my solution in case someone would need it. At first I wanted to put it in a comment below skuwid question but i was not allowed to do that so I posted it as an anwser.


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What is Protected Layer?
I found some explanation, but there is not difference between Protected and Unprotected layers for bones.
Theoreticaly if I have my bones protected it will be linked to scene after Make Proxy. But it is also linked with unprotected layers. If I will do some changes in bone hierarchy it is propagated to my scene too. So where is difference?
It looks like some old function from previous Blender version.

http://urchn.org/post/protected-armature-layers

I also found this link, but it is not true all yet. So I asked here.

I just posted the link in case you haven't seen it, often older resources are still valuable when explaining ideas and concepts even when the implementation has changed.

I found this differences:
If you add some constraint (IK for example) to your source blend with protected layers, it will be also in your destination scene.
You have to key your pose, because it will be reseted after reloading.

It is to do with the way blender links armatures into other files. In the final video of Humane Rigging Nathan says that non-control bones should be on layers that have protected enabled and control bones should be on un-protected layers.
Even Nathan doesn't explain it much but it has something to do with the way armatures are linked between the original file and the proxy rig in another file. We are not meant to modify any rig bones in unprotected layers once the armature has a proxy rig in another file.

Does this mean that every blender file with a proxy rig of the original would have a different or same rig bones compared to the original linked file?


text:
How can I mirror weight painting?
How can I mirror my weight painting to the opposed side of my character? I know that there is Mirror function, but it doesn't assign the weight to bones on the opposed side. Can I do it manually?

You find more details one mirror editing here:http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/Advanced_Tutorials/Advanced_Animation/Guided_tour/Armature/edit

I watched your link, it is about rigging, but I need mirror skinning. I also know that there is X-mirror, but it simply copy my weight to counter side, but to same bone. It looks that Blender don`t have this function.

It has. You need to follow a naming convention for it to work. Each pair of bones need to have the same name with the suffix .L for the left side and .R for the right side. E.g. UpperArm.L and UpperArm.R. In the weighting Options of the tool panel turn on "X Mirror". You dont need a mirror modifier for it to work. See http://wiki.blender.org/index.php/Doc:2.6/Manual/Rigging/Armatures/Editing/Properties and look for "Naming Conventions"

Some will also find useful this answer

Each pair of bones need to have the same name with the suffix .L for the left side and .R for the right side. E.g. UpperArm.L and UpperArm.R. In the weighting Options of the tool panel turn on "X Mirror".

Is there a way to do this after the weights have been painted?

The mirror modifier takes weights into account:

In Weight Paint mode you can edit the weights they would be applied symmetrically.

This is working for one bone, but I need mirror skin to opposed side, so there is another bone, not same.

Just wanted to say thanks, Stacker, for the tip! As long as the mirror modifier is FIRST in the chain, you can edit vertex weights however you like and have the result mirrored perfectly. It even mirrors manually assigned weights to individual vertices! This in particular is not possible without the modifier, as only weights "painted" by a brush would respect the built-in X-Axis mirror feature, and not weights assigned manually in the Vertex Groups list. In that case, you would have to mirror the vertex group, which is tedious for many changes. So for ultimate mirroring, use the modifier! :-)

Select your object then select vertex group

Select group you want to edit
Click the dark down_arrow to its right

Copy Vertex Group
Then click on the same down_arrow and Mirror the original of your
vertex group

Last step delete the original then select copy and rename it to
original.

A suggestion would be to rename the copy to ".R", so you don't have to delete the original ".L" group. So copy "shoulder.L" (making "shoulder.L_copy"), mirror the copy, delete the preexisting "shoulder.R" if it exists and then rename the mirrored group to "shoulder.R" so it takes its place.

How to mirror existing weight painting from one side to another
There's also another option where you can select a bunch of verticies and mirror all of the weight painting from the opposite side, without having to manually mirror the vertex groups for each bone. I found this was a lot faster for mirroring the weight painting of my model's hands.
Here's the steps on how to copy the topology from side A to side B of your model:

(Optional): If you've updated the topology of side A, then you should apply those changes to side B first.

Delete the corresponding verticies of side B
Select your verticies in side A in edit mode
F3 search for Symmetrize to duplicate and mirror the topology to side B

In Edit Mode, select all of the verticies on side B that you want to update.

These verticies will have their weight painting copied from the other side

Switch to weight painting mode.

Enable vertex selection, then click Weights > Mirror

Make sure to select All Groups in the little window that pops up in the bottom left corner

Source: https://youtu.be/Ha_YU5xJsSc?si=YaGwbSWoVZ3hWMyX&t=89.
Tested in Blender 4.0, but the video is for 2.8/2.9.

"This is working for one bone, but I need mirror skin to opposed side, so there is another bone, not same. "
In my experience the mirrior modifier won't create vertex groups for you. If you have a vertex group named Arm_Right you need to add a new vertex group and name it Arm_Left before you use the mirror modifier.


text:
Blender writes render even when there is no composite node?
I am new in Blender and I would like to know what is best workflow for creating output to many files and compose in AfterFX or in Blender Composer.
I know that I can render from Blender finished composed frames, but it is not ideal, because if you want change color correction or DOF you have to rerender whole frame :( So much better is render it to PNG, EXR ... and compose later.
I discovered that best option is don't use Compose node, but only File Output. But there is some hidden compose node, which save my render together with File Output, so I have to delete this files (I named it null). I can rerender only some layers and let others unaffected. But maybe there is better workflow ... thanks for tips.

I also reported this behaviour and Sergey added this to TODO list: Report
Sorry for my english :)

I think this just the way it works currently. :/ (I have noticed this too). It would be fairly easy to write some python script to delete the files automatically.

I think OP wants to use the z-pass for DOF. Using the z-pass and post-pro you can easily change the DOF. Whereas if you render out a flattened image you would have to render the entire thing over.

There are couple hacks/solutions you could try, such as: 1. Set the scene output to a separate directory so it is easy to delete the extra files. 2. Use only the composite node with multilayer EXR to store all the passes. 3. Use a combination of the scene output/composite node and file output nodes. Would any of these work for you?

gandalf3: 1) yes this is what I am doing. 2) use composite node is dangerous, because when I rerender only one another layer, I lost my layer with composite node which was fine. EXR multilayer looks good, but slow for loading and I have to rerender all. 3) same as 2). Thanks, I thinked that there is some better workflow, it looks that File Outputs and redundant Properties Output is best solution. Hope that developers change it :)

As gandalf3 said, I think the best way for now is to delete the files automatically with some python script. Just make sure that the scene output goes to it's own directory, so you don't delete any other files. Run the script and render.
import os
import glob
import bpy

def delete_garbage_files(scene):
    out_path = bpy.path.abspath(scene.render.filepath)
    out_dir, _ = os.path.split(out_path)

    # Remove all files of the currently selected output format.
    ext = scene.render.file_extension
    for f in glob.glob(os.path.join(out_dir, "".join(("*", ext)))):
        os.remove(f)
        print("Deleted: {}".format(f))

    # Also delete the directory.
    try:
        os.rmdir(out_dir)
        print("Deleted: {}".format(out_dir))
    except OSError:
        print("Didn't delete directory {}, probably not empty".format(out_dir))

# Post render handler, to delete the files after every rendered frame.
bpy.app.handlers.render_post.append(delete_garbage_files)

To delete the files after the whole render job finishes, you can use render_complete instead of render_post But if you cancel a render, the files won't be deleted.
# Complete render handler, to delete the files when the whole render job
# is finished.
bpy.app.handlers.render_complete.append(delete_garbage_files)

Probably the best solution is to use a render_cancel and render_complete handler. Then the files will only be deleted when the render is finished or canceled and not after every rendered frame.
# Use both cancel and complete render handlers.
bpy.app.handlers.render_cancel.append(delete_garbage_files)
bpy.app.handlers.render_complete.append(delete_garbage_files)

If you want to automatically delete the 'garbage' files the next time you open the file and render, you should have the name of the script end in '.py' and check the 'register' option:

Just realized you also have a render_cancel handler. Updated the answer to reflect this.

*** Edit this DOES NOT WORK !!! the files will still be written but in the Blender installation folder.
The post is old but just to let others know, I have a better and simpler solution, simple erase the file path in output under the render configurations. I also have the composite node in my node graph and still works.
works with blender version 2.76.


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Store bpy.context.selected_objects for later
Hello I'm looking for an optimised way to store a list in the Blend File. I'm guessing I need to use Property Groups
Basically what i Need is a way to store:
bpy.context.selected_objects

In a list
This list should be able to be accessed at anywhere and only be cleared when a method specifically clears it. e.g not disappear when Blend-file is saved and closed and then reopened.
Reading, storing, and clearing list needs to not take too much time since this list might change within 1 second when a slider is changing.

lis = [obj for obj in bpy.context.selected_objects]

No this is not a solution. it's not saved when leaving the function or closing the blend-file

How about save the data in blend file?

I think you want to look into using a pickle file.

Save some data in blend file
import bpy

for obj in bpy.context.selected_objects:
    obj["my_attr"] = True

# not work for unsaved file
bpy.ops.wm.save_mainfile()

The next time the file is opened
import bpy

lis = [obj for obj in bpy.data.objects if "my_attr" in obj]

cool that's pretty useful


text:
How can I transfer normal of cube edges to curve tilt?
Here is my problem.
Ideally I want to procedually make frames like this.

I start with a default cube and [mest to curve] it into some curves. After I use a custom profile shape to [curve to mesh] the curve and set the tilt to the edge normal of the cube, I got this.

I think it is the tilt that im doing wrong.
All the edges are facing wrong direction and twisted, not even close to the edge normal of the original cube.
I might have the wrong understanding of how the tilt/normal/vector things work.
Can you help me to set up th node?
Thanks for your time!

If your question has been solved, please be so kind and mark the answer that contributed to the solution as "Accepted answer" so that this question will not continue to be displayed as unsolved. Thank you! Here you can find more information: What should I do if someone answers my question?. If you still haven't gotten a solution to your question, please be kind enough to address it.

I'm not sure if you would have expected such an answer with your request and if you will be happy with it, but unfortunately there is no ready solution for this task in Geometry Nodes.
What I think you're looking for doesn't even exist as a standalone modifier, unfortunately, because the way I see it, you'd like a tool that converts the edges of a mesh into a wireframe with a profile.
Unfortunately there is no such (built-in) tool.
But maybe this node tree is a solution for you:

Here I calculate an angle per point based on the normals of the edges and the generated tangents and normals of the curves, with which I feed the node Set Curve Tilt.
...has become a bit complex, but I don't think it can be much simpler.
Also, with all these solutions you have the problem that it is hard to create a solid mesh (depending on the profile) and it also only works with a cube.
Maybe the following articles will help you with this topic:

Vertices are not connecting
How do I align the edges with the corner cubes?

(Blender 3.2)


text:
eevee principled volume shape is off
I was tring to use principled volume to make dust that flow along the ground surface which is displaced to a certain amount. My first try is to distort the volume box mesh by shrinkwrap a plane to the ground mesh then solidify it. But it seems eevee volume is only work with the bounding box instead of actual mesh of the object.
Then I take another try that use raycast in the gn node to sample the ground shape to get a z shift to mix with my dust noise texture. So that the noise will be curved to control the density of the volume. But still the volume is only shown my noise part of the density, ignoring the attibute I transfered from gn node(named “12” in this case).

Can someone let me know is this just a engine issue or am I doing something wrong.

Eevee is not capable of using the shape of an object for volumes, it will always use the complete bounding box. You need Cycles for that.

@GordonBrinkmann thank you Gordon! But I've already figured it out as I said in the first half of my question. But what about the second half of my question? It is not about the bounding box anymore. I used a curved noise to control the shape but it is still not working properly.

Yes, you figured it out, but you wrote "it seems" - sometimes things are not what they seem, especially newbies might not know if it is as it seems or if they are doing something wrong. So I just wanted to clarify what you discovered is definitely the case here. For the second part, well I didn't have time to decode your node setup and have no answer for this - that's why I just wrote a comment on volume in Eevee and did not post a full-fledged answer in the answer section.

@GordonBrinkmann Thank you for the clarification! It dose help to build my knowledge.


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how to input field into group nodes?
I'm working with a street generator right now. I have a single building packed into a node group already.
Next I want to generate these buildings on points that are generated from a mesh line.
As you can see in the gif, all the buildings now are having the same input so they will look exact the same.
My question is if there is a way to use field or something else to randomize the input of each building so they can look different other than having tons of this nodegroup and manually set up the input one by one.
I also notise the input of the nodegroup is a circle instead of diamond, which means i cannot input field information into it.
and I dont know how to make it diamond.
thank you for your time!

This question has been asked many times, and unfortunately the answer is still: No, it doesn't work. At least it doesn't work that way. If you instantiate a parameterizable object, you cannot change the parameters afterwards. With Instance on Points you create "copies" of an object. And there are no loops in GN. Therefore you would have to pack everything into a single group or structure it differently if you want to approach a solution.

Thank you quellenform for commenting this issue. I totally see the limit of this method. Will try some other approach and wait for the update about this topic. Once this limitaion is cleared out I will spent time on the next step instead of trying to solve it and waste my time. Many thanks! Have a good day pal!

as a "start" and to learn some "principles" you can use this node setup:

It is far from being perfect, but maybe it gives you some ideas!

Thanks for your answer Chris! I got your idea of randomizing the scale. Btw the shifting of the roof top is a brillant move! But this is not enough for my project. I need buildings to be different in a more foundamental way like different floor numbers or more rolls of windows. I think quellenform's answer explain the main issue of this method. It creates "copies" of mesh and can not be altered afterwards. But still there is something learnt from your setup! Appreciate it! May you have a wonderful day!

Thanks, you too!


text:
Create Cross Sections and 2D planes in Blender
I have a model of a canoe in Blender that's about 12' long - I wish to break it up into 12 sections so that I can print out each individual cross section and set up the forms so that I can cedar strip my custom canoe! Is there a way to break up my model into these cross sections?
Also, I would really appreciate if somebody could show me how to take these cross sections and get them onto paper somehow, or maybe I'm asking too much now? Sorry
EDIT
Can't figure out how to attach Blender files in comments but here's what I did
My canoe :

I actually went a different route and decided it would be way easier to make a Stand Up Paddleboard, so I modified the canoe (shrunk it) and played with it a little until I got the shape I liked
Then I used the method outlined by AliasGuru to create the cross sections!
I'm going to put them into Photoshop and resize them to what they should be, and then export them as PDFs so I can print them on a large size plotter.
I can only post two pictures because I don't have enough reputation, but it looks really nice! Currently trying to get Blend Exchange to work so I can post the actual blend file.
Thanks for the help !
EDIT 2:
Got it:
Be aware that the cubes are not correctly numbered.
Still can post only two links so I'm going to have to get rid of another picture, sorry!

Can we see an image (or better the exact file)?

Done! Sorry for the delay

depending on how sophisticated you want to go, there is a few solutions to this. If you manage to create a closed volume from your boat model (the hull I guess is the part needed), you can do it using the Boolean modifier.
Create the volume first. If your canoe is only a shell, you can use the solidify modifier to generate some thickness. if the volume is closed, you're good to go.
Create a cube and scale it so in one axis it is really flat. This will be the thickness of your section:

Add a boolean modifier, set it to 'Intersect', and choose the boat hull as the object to cut with (in the former screenshot my object is the 'Dragon'). If you now hide the boat hull, you should see the first section.

Now you only need to duplicate this object across your boat with constant offsets. Press Shift+D, X (if you want to go along the X-Axis) and then type in the amount (like 0.1) Enter. You should now have a second section in place. If that worked, hit Shift+R, which repeats your last operator (duplicate and move), and do this 10 more times to have 12 sections in the end.
These objects can be now individually selected (that's why I did not use an array modifier) and put on layers if you like. If you select one of the elements, you can see the dimensions of the bounding box (I made it visible in the screenshot) in the Transform tab:

This you can use to resize the section images later on to correct size in Photoshop or Gimp (unfortunately no way to do this out of the box afaik). Getting the images is a matter of setting up Blenders viewport and do some openGL renders. Setup a new World, make it white, and set Blenders viewport to show the world and only render:

Using the 'render OpenGL Image' button marked in the screenshot above gives you an image in the resolution set up in the render settings, so you can go for really high res templates if you need to.

For scaling the images to correct size you'll need to consult the image editors manual.

This was really great, and exactly what I needed! Thanks so much for the time you put into this

would be cool if you could post a photo of the model once you're done!

Will do! Can't do it now but I'll start working on it later tonight

I was thinking of a picture of the boat after you built it for real, might be in a couple of weeks  :) but anyways, promising 3D model!


text:
Difference operation on Boolean modifier not showing once applied
I have checked normals and removed doubles but still cannot get the Difference operation on Boolean modifier to work properly. The choker object is hollow, however I expected the modifier would still function using these two meshes. My aim is to cut a hole at the end of the choker. I am able to use the modifier using other basic shapes in a new file. How can I correct this problem? The choker object is hollow to save on material costs when used for 3D printing.

Another option you can try is Knife Project

The simplest definition of Boolean with the Difference operation is that it eliminates the common region that is occupied by 2 geometries.

In your project, You may notice that both the geometries share a common region.

You added the modifier to the Cylinder with Choker as the target object.
Ultimately the some the Cylinder part will get removed as the modifier is for the Cylinder, not for the Choker. But you want a hole in the Choker.So the best solution is to add the Boolean modifier to the Choker, with Difference as the operation, and the target object as the Cylinder.
However there will still be some portion remaining in the bottom.

So you have to apply the modifier and delete it in Edit Mode. But you may have to apply the first 2 modifiers to get the desired result.

Hope this helped!


text:
Shrinkwrap modifier creates creases on object

Faces which have been extruded are flat in object and edit mode, but is deformed when rendered. How can I prevent the creasing from happening when using the shrinkwrap modifier tool? Sorry for the simple question, I am new to blender and have never asked on this site before.

Ah, this is something I knew and should have remembered. Thanks for pointing that out to me! @cegaton


text:
Banknote is faded
I am modelling a slim wallet with some bank notes on the back.
Unfortunately, when I light the scene the bank note loses the color and looks faded.
I reduced the lights to a minimum but that didn't really help.
Without the Principled Shader it looks good but unreal because the shadows are missing.
Has someone an idea what I can do to make the colors more pop out?
Thank you for your help!

You could always add some saturation, but is the result really so far off if you looked at a real bill?

You should also check what color space the image is in

Did you try to increase the Roughness value?

Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.

Try using Standard View transform instead of Filmic:

I would advise against using the standard view transform (sRGB OETF). Instead either use Filmic with a "look" that has an increased contrast and/or perform proper color grading in the compositor. Although adjustments to the material could also be necessary.


text:
Loop selection with imported models
I imported a model of a credit card and want to round the edges with the bevel tool.
Is there a short way to select all the edges around the card without doing it manually edge by edge?
Loop select didn't work for me, even though the loop is fully connected and there are no double vertices.
Thank you for your help!

select chunks by chunks with alt + click

there must be a problem somewhere in your faces chain if you can't select the ring, please share your file

If the Card is flat (without number/name geometry) the fastest way is to go to Top View (Num 7) and select with Select Box selection all the vertices and assign Bevel. Try also Mesh > Clean Up > Merge By Distance to merge the overlapping vertices to get more clean Alt+LMB selection.

Select a face, press Shift G > coplanar, then go to Select Menu > Select Loop > Boundary Loop.
Another method, select a vertex, hold Ctrl, select another vertex: shortest path will be added.


text:
Emisson pass over Glass
everyone!
I came across a problem with emitting light through Glass in Cycles - a police siren - No matter what Emission value I set, it stays this dim.

Glass:
Glass BSDF
IOR: 1.450
Roughness: 0.0
Emission
Basically setting any value higher than 1000 has no effect
I tried lowering the IOR of glass, mixing with transparent node, that however created very strange, burned, overexposed effect with the light being pink.
P.S. I want to avoid multiple Render layers, though for now it seems like the only option, or even if possible at all.
I would love to achieve this effect:

Thanks for any help!

did u try glare node?

I'm wondering like @Chris if you tried compositing or do you expect it to glow just by increasing the strength? These glows and lens flares etc. which you see in real photographs are usually an effect of overblown light sensors in cameras, lens imperfections and don'T let me get too technical here, but a virtual camera in 3D software doesn't have this. All is rendered crisp and clear until you go and create something like glow effects in compositing. Also things like depth of field or motion blur do not happen naturally with virtual cameras unless you tell them to calculate such things.

For the light getting pink, well that depeds on what basic color you have set for the light. For example if you have RGB (1, 0, 0) than it will mostly stay completely red, since green and blue are not present and multiplying with some strength doesn't increase them (if Color Management is set to Standard, but Filmic might change these base values). If however your green and blue values are > 0, then they will change the color the higher the emission strength is. A higher blue will make it pink, a higher green will make it orange. Until the strength is so high that it gets all white.

I found the problem to be in the Glass shader itself - since it did not pass enough light, it was not the problem of Emission being pink (the RGB node was full red). When I adjusted the glass (for a more realistic one also) node, the light was way more bright, able to be composited later on also. Hope my last post explains... Thanks guys anyway for digging into it, appretiate it! ;)

Thanks for the suggestion with glare, however the problem was with the Glass. Just in case of anyone interested I am posting my solution:
I brewed this material for the transparent cover of the siren, that allows to pass way more light from the emission

Glass before:

Glass after:

I played with the compositing also to get control over the Glare effect, since it created strong outlines on default value:

This is the final result I am satisfied with (I did not go for the full light effect at the end)

try this nodes setup in compositing:

material:

Thank you for the suggestion! ;)


text:
How can I stop the texture stretching when randomly scaling Instance on points in geometry nodes?
How can I stop the texture stretching when randomly scaling Instance on points in geometry nodes?
I am creating a city with randomly sized buildings. The tall buildings are getting stretched textures.
I have tried a few things seen in some videos but nothings working for me.
Has anyone any experience with this?
Thank you.

Are these textures added by UV? Object? Generated? Another method?

You might try to add the texture via geometry nodes on each instance, considering the scale in mapping.


text:
Children animation is wrong
I have two objects one Parent and one Children. I have translate animation on parent, but when I add keyframe to children, children jump to another position in playback. What I am doing wrong? In Blender I can not animate children??

Can you post the .blend or a screenshot and tell us what version of Blender you're using? I'm not having this issue in the latest build of Blender with two parented cubes.

I found it ! :) I had turn on Visual Keying in Preferences under Editing. Is it normal behaviour with this ON?

Yep. It can sometimes cause a bunch of issues with constraints and parents.

From manual: Visual Keying
When an object is using constraints, the objects property value doesnt actually change.
Visual Keying will add keyframes to the object property, with a value based on the visual transformation from the constraint. ... but I still dont understand what does it mean :) Have I report bug with my children parent behaviour? Why there is not any exception.

I think it has something to do with the parent position affecting the child position, and the child position is relative to the parent position somehow.

If I disabled Visual Keying under Editing in User Preferences, problem was solved.


text:
How create Action strip for more objects in NLA
how can I do one clip for many animated objects? I can add objects to Keying sets and key together, but clips are created separately for every object, but I want create only one clip. Thanks
EDIT
For example: I will create robot with custom rig. Two legs, one body, two hands. I dont want use armature. And if I will make walkcycle I will have many clips for one walkcycle? It has not sense for reusing, because I will have many clips for one walkcycle. I can use Armature, but often it is not character animation. Last project what I done was house which was rotated, open roof and open windows. This action was repeated. So in Softimage I made clip and used it again. Without armatures or any bones. Maybe it is not possible in Blender.

So after discussion in another forum: http://blenderartists.org/forum/showthread.php?321310-Create-clip-for-more-objects It looks that it is not possible :( I can only use armature as workaround and use parenting objects. Bones dont have to be connected, so I can create only one bone for one object, but I can create clip for all bones together.

You only need to animate one object, then copy it to the others. To copy, select all object you want to use the same animation data, the one to copy from as the last selected. Then execute Object > Make Links... (shortcut Ctrl-L), and choose Animation Data.

Note that if Location property is keyframed in the action, all objects using the action will jump to the same location. To offset from original location, use Delta Location instead. The same goes with Rotation and Scale properties.
EDIT: If you want to merge animation data of several objects, I don't think that's possible. At most, you can manipulate all of them in the Dope Sheet, where animation data for all animated objects are displayed. I use this a lot when I have to synchronize the animation of several objects (three, in illustration below) at once:

Thanks for tip with Delta Location :) Maybe my question was not clear, because you answered for another thing. I try it differently: I came from Softimage, when I create some complex object, I create rig for animation controled by null (empty node in Blender). I want animate every empty separately, I dont want share animation. But in Softimage, I group all "empty" under "Model" and I can create only one clip for all emptys. And now I want same in Blender. But I have one animation clip for one control empty. Maybe there is another workflow in Blender.

@user2332312 Yes, "create one clip" is a bit ambiguous :) Edited my answer.

Thank you, it is really bad :( I also used Maya and this is normal workflow. Maybe there is another in Blender. For example: I will create robot with custom rig. Two legs, one body, two hands. I will not use armature. And if I will do walkcycle I will have many clips for one walkcycle? It has not sense for reusing, because I will have many clips for one walkcycle. I have to watch some videotutorials for workflow.

@user2332312 Any reason why you won't use armature? So far, armature is the only way in Blender to have virtually unlimited objects to control in one animation data. The workflow you've described seems harder than it needs to be, for character animation. CMIIW.

@user2332312 If you want to clarify your quesion, please edit on original quesion instead of commenting. Btw, I'm afraid you still need a more detailed example to explain your question better. You comments seem too far from the original post.

Adhi: I added example in above, when Armature is not good. But there is many another example. For example camera rig. I can animate camera, interest node (in Blender you have to create it) and whole camera root node. All this three object will animate together and create animation clip in NLA. Later I can reuse it.


text:
The basics of how to start modeling
I am having a lot of trouble starting with blender. I am trying to make a train track to start but I am having a lot of trouble creating the shapes. When I click on Add → Mesh → Cube, it gives be a cube that I do not know how to resize.
What are some general ways that I can resize, modify and go about transforming the default primitive objects in Blender?

For a very, very quick start. The absolute 3 things you need to know to begin effectively modeling in Blender are:

Interaction Modes

Object Mode
You are placed in object mode by default when you add a new primitive. You can translate, rotate and scale the object along the three axes whilst in this mode but to get finer control, you want to enter edit mode. Use Tab to enter edit mode from object mode.

Edit Mode
In edit mode, you have access the underlying structure of the object, you have much more control here and this is where you will spend most of your time when modeling. Likewise, use Tab to exit edit mode and enter object mode.

Mesh Select Modes
Once you are in edit mode, you have 3 different control handles that you can use to help shape the mesh. These are pretty intuitive so I won't explain them and you can read more about these on the relevant wiki page.

Vertex

Edge

Face

Mesh manipulation
This is how you can shape and tweak your mesh. While you can do this object mode as well, you have much more control while you are in edit mode as you have access to the mesh control points.

Translate

Rotate

Scale

If you can understand those, you are on your way. Once you are past this stage, you can start looking at more advanced things such as extrusion, beveling and modifiers etc.
There is too much information to go into here and this should suffice. Your next steps would be to:

Watch some introductory video tutorials (archived), more tutorials for modeling in Blender.
Read the introduction to modeling on the manual.
Browse the modeling and workflow tags on this site for more tips and tricks such as this.

Also, some common shortcuts that you should learn are:

G to grab (translate)
S to scale
R to rotate

Nail these basics and you will be making your own models in no time, using the basic steps above, you can make your train tracks easily by just scaling and translating simple cubes.

You need to be in edit mode to model. Press [tab] or select edit mode in the toolbar.
You can then select the dots (vertices) using right click, and change their position.

Use G to grab and move the vertices around.
R to rotate them
S to scale

By pressing X, Y or Z immediately afterwards, you can limit the transformation to only one specific axis.
You should have a look at this modeling introduction:
http://useblender.com/Basic_Modeling.html


text:
I want to make animations, is Blender the right program for me?
I want to create a short 3D animation series. I found out about source filmmaker but as time goes on I am starting to look elsewhere.
It will be a simple male character, holding a monologue behind a desk. I would want to save certain gestures for use later — for example, once I get a few different goodbye waves, I might not need to create another and being able to recall or save old gestures would be great. It also would be the same scene (sitting behind a desk).
I started off with using source filmmaker, but as I learn more about it I realize I will be using custom stuff anyway and it might be smarter in the long run to start with something like Blender instead.
As you can tell I'm totally new and realize that it will take months before I am ready, but I figure I'll ask as I want to make sure I'm heading in the right direction.

Yes, Blender is the right program for your purpose :)

Don't be intimidated by the interface, many of us have overcome it, and so can you ;-) But the interface will also be getting an overhaul in the "near" future, so it should only get better.

Blender is definitely a good program to use, seeing your purpose. It just needs a bit of patience and practice.
And  about saving actions — it can be done using the action editor in the Blender interface, so that you can use it multiple times. Though you should go through some tutorials on how to do this. There are numerous tutorials on YouTube that explain this functionality. Here's a link.

You can do all of what you want to do with Blender. I believe Blender has the ability to save gestures, and it's animation tools are pretty nice. I know you can save frames, and then go back to them later, so if nothing else you could copy and paste.

Blender is the perfect program for animation. Check out the various animation movies made with Blender on You Tube. You get great tutorials on You Tube as well and there is a vast community of people using the program always willing to help. Look no further!


text:
How to get topographical contour lines like shown in manual? Analogous to Rhino3D functionality?
The Freestyle SVG Exporter page in the manual shows this image:

but doesn't really have any indication of how to achieve this contour line look...
I did some more digging around and found an article from 6 year ago with a similar image, that had a very similar picture and provided a script, which I've yet to try (haven't messed with scripts in blender yet...):

Is there a more "official" way of achieving this? I know e.g. Rhino3D has contour line command so I'm wondering if blender has anything similar?
edit: I want to render the scene as an svg, should have specified. I got the script to work, but it's destructive... it operates on the mesh directly unfortunately. If anyone can find a way around this would be helpful.

Do you want to export it as a svg or just render the lines ?

Related : https://blender.stackexchange.com/q/114345/29586

@Gorgious want to render as SVG... should have specified

I suggest ask a new question on this link this one

It took me a lot of effort, but I've got a separate solution here: https://blender.stackexchange.com/questions/304713/how-can-i-highlight-the-hard-edges-on-a-very-large-10-km-model/306561#306561

Simple node setup that uses the separated Z texture coordinates and modulo to drive a repeating color ramp.

Use the green cursor on the ramp to change thickness of lines.
Use the Z Scale to adjust line space
For the ground, same texture but using the X texture coordinate component.

thank you! This does answer the question as it was posted. Though I left out an important detail, the fact that I wanted the lines to render as an SVG. My fault, so I'll mark this as correct in a few days if no one else answers.


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Particle System bake fine individually, but mess up when more than one is baked
see gif below. Have different emitter/curve pairs in different collections, with the curves set to act as paths for the particles of the emitters. I have the Particle Properties > Render > Render As set to "Path".
Here are the steps I show in the gif:

Bake the particle system on each emitter individually, deleting all bakes in between.
Bake one emitter, then another, without deleting bakes in between. This is where the problem happens.

I don't know if this is relevent, but I tried using the "Disk Cache" then Bake, and the program crashed (not shown).

using blender 2.92.0

I found a temporary fix by checking "external" in the cache section and then unchecking it, alt+dragging. idk how it works but it does. mess still happens if I press play after though.

This site is for helping with working in Blender. I'm pretty sure the program crashing is no intended functionality, so this is probably a bug and should be reported (Help > Report a Bug). On this site we are no Blender developers or in any way affiliated with the software so we cannot help with bug fixes, so this question is considered offtopic here. Apart from that, 2.92 is an older version and it might well be that this bug is no longer present in newer versions.

@GordonBrinkmann the crashing was not main issue, it was just a detail I included in case it was relevant. I'll edit it out. The issue I'm asking about is the baking behavior described, and shown in the gif. I'm trying to learn if there's something I might be misunderstanding about the cache/baking functionality, or if that behavior is unintended/a bug . I'll update the program soon and update the question if anything changes.


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Unequal weighting between black and white in cycles; white has greater weight than black
Using blender 2.92.0
I'm having an issue where the weight of the color white is greater than that of the color black when using nodes. It's hard to explain, so please check the images, I'll try to attach the blend file tomorrow.

See how the white band is significantly "thicker" than the black?
Both object are the same in every way except for that one has the order of the colors going into the mix shader flipped. I'm using a "mask" node I found online to get the behavior around the edges.
Here's what the node setup looks like:

I've tried to understand the issue on my own and believe it has to do with luminance; I understand that when a color node is connected to a factor node, blender uses the luminance value.... but that still doesn't really explain the disparity, since both setups are using the same mask and colors, just a different order of colors...

I see that you are used to working with gamma corrected colors or sRGB color model. It has some kind of symmetry - whites and blacks increase and decrease perceived brightness in the same speed.
But Blender uses linear colors - to imitate real world lightning. In real world and in linear colors, white has to add more energy to make it lighter than the black.

You might see this in color wheel in blender, then mid-gray actually 0.22 in linear color:

This is also the reason why you have to use non-color in normal maps.

That explains a lot, thank you!! But, how do I go about resolving this? I tried messing around with color ramps and gamma nodes but I'm still not really getting anywhere... how do I have the colors appear closer to their gamma corrected values? My use case is that I want to use the edge as a mask for transparency, so that the races look like they fade into nothingness towards the edge.


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Efficiently creating noise in animations
Organic animation in Blender looks a lot more convincing when everything has a bit of jitter to it. I'm trying to find an efficient, clean way to do this.
F-Curve modifiers are the obvious solution, but they have a few issues:

I need to apply a modifier for every single channel I want jitter on. This means making at least three copies for X/Y/Z position
With Euler rotation, I can apply noise to the X/Y/Z axes, and that works very well. Quaternions are much less straightforward. I can't predict the impact of jittering one or more of the W/X/Y/Z values; they're interdependent and rather incomprehensible!
Briefly enabling/disabling the jitter is not easy. You can't keyframe or add a driver to the Influence value, and the Restrict Frame Range values similarly static.

Some other answers have suggested using the non-linear animation system. However, I can't find a way to do anything but add jitter to every single channel the strip controls, which isn't viable (even if I wanted noise on every channel, this applies the same noise function to everything). I'd like to have different amplitudes/frequencies on different bones, along with different offsets so the channels aren't all perturbed identically.
I might just be misunderstanding how it works, of course!
I'm considering writing a script to do it for me, which seems pretty viable (input the bone and the jitter parameters, then create the modiifers automatically). However, this is still going to leave a ton of F-Curve modifiers lying around everywhere.
Animation Nodes actually sounds promising - it'd be fantastic if I could just take my original, jitter-free data and add noise to it via nodes, which are easy to create and combine. I'm not sure if this is possible, though.
So, in short: is there a "best practice" for accomplishing this that I've missed, or do I just need to bite the bullet and do some manual work?


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Is there a way to prevent objects from clipping through one another?
I have a scene I'm working on where my character is getting up and out of a chair continuously, putting their hands on a wall, etc. It's kind of tedious to go through and make sure the actor doesn't clip through the object every time, so I'm wondering if there is a way to get the actor and the chair to interact.
Basically, what I'm trying to do, is be able to push the actor up against the chair and it stop upon making contact. Is this something that can be solved with physics simulations? I'm pretty amateur when it comes to most things with Blender, but physics is a whole other monster I've yet to conquer.
I have vague memories of doing something like this in the past, but I think it was with a singular object and I was only modeling. With this I have multiple objects and an actor that I want to interact with them.
If you took time out of your day to read this, I thank you, hope all is well.

Add a collision modifier to the wall?

i think physics simulation is over the top for that. in my experience a little bit of clipping is good to give the illusion of contact. and you only should worry about it when it's visible (like in a close up shot). Also copy/pasting poses can save you some time


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Boolean Operation On Linked Selections
I'm using the sapling tree generator which creates many branches as "separate objects" but in reality they are joined into one object (sapling uses curves which i then convert to mesh). I am able to select a vertex on a branch, do a Ctrl+L and get a whole branch selected. That is what I mean by "linked object", a branch.
What I am trying to do is take all those branches and do a boolean type operator on each other to create one object that does not intersect itself. Or at least create many objects out of the branches with "Cuts" along the intersection. Is this possible?

This might help: You can select the trunk instead with  Ctrl + L (use Ctrl + I to invert selection if you prefer the branches instead). Press P separate them by selection. Do the boolean operation. And then use Ctrl + J to joint trunk and branches into one object again.

it might be worth mentioning there are different branch levels, so trunk is 1, branch level 2 may have branches from there as well. so there could be many join operations to go through. There are some hundred branches that need joining. I need to try out what you suggested though and see how that works! Thank you!

Ah, okay. : )  In that case I would select the tree, press P > separate by loose parts. Then activate the Bool Tool add-on in Preferences > Add-ons. It will then be located in the 3D Viewport > Sidebar > Edit tab. Select all your separated objects (and the trunk last just in case, so it has a yellow outline instead of orange) and click the Union button under Auto Boolean. I tried it (and it works) with cubes so i think it worth a try.

I think we are getting somewhere, but perhaps i did something wrong. There are many branches including the trunk that are now missing after the union operation. I will play around with the selections of branches.

I tried it with the default Sapling Tree Gen tree. (and on second thought i think the order of selection before the operation is not important) Blender froze up for a moment after clicking the Union button, but after a while it yielded the expected result. I can't say the topology where the branches meet is pretty, but it should work as i described it. (although you never know with boolean, especially from before Blender 2.9). In any case, i hope it'll work for you. good luck.

My apologies, on closer inspection i did find some missing branches. Maybe Union joining them in a few separate batches might work.


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How do you export a comp and not re-render the animation?
Whenever I try to export my animation comp by pressing Ctrl+ F12 or Render > Render Animation, Blender just renders my scene again rather than exporting my comp.
How do I tell Blender to export my comp, NOT re render the animation? I've tried deleting everything in the scene so there's nothing to render, but then Blender just complains that there's no camera in the scene.

What is the content of that you call "my comp"?

If you're asking what's going on in my composite, it's just a single rendered sequence with noise reduction and lens effects. It shouldn't affect my problem.


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Imported object is locked to world origin
I try to import an fbx file which I have done many times before. Now suddenly it is locked to world origin so I can't move it. It is getting deformed when I try to move it because it is locked there.
The object is an animation figure from Mixamo. I am using Blender 2.81. I have even tried to restore factory settings, it won't help either.

A few things you could do to fix this:
1) set the origin of the fbx file you imported to it's own geometry.
You can do this by going to object > transform > origin to geometry in object mode with the object selected.
2) you can set the object to be it's own user.
This is a fix for an error caused by linking objects from other scenes. Somehow your object might have a similar response, so setting it to have it's own user may help.
You can do that by going to object > make single user > object. Or if it has a material or data then object > make single user > object & data & materials & tex.


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Smoothing the edges of an fbx file
I want to import an fbx file and texture it, but when you have a closer look at the model you can see the single edges, even though I used auto smooth and applied shade smooth.
To use the subdivide modifier I would have to add some edge loops but that is more a workaround.
Does someone have a solution for the that? Or does it depend on the face count of the imported model only?
Thank you for your help!

shade smooth will just affect the shading, it won't make the silhouette smoother. I don't think there's any other solution than subdividing your mesh (or giving it a Subdivision Surface modifier)

Well, of course, if it's a low-poly model it would still appear jagged even after Shade Smooth!
An easy workaround to adding edge loops is adding a Bevel Modifier before the Subdivision Surface Modifier and playing with the bevel values.


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How To Copy or View Existing Vertex Parents
I have a problem with Vertex Parent.
Is there a way to either:

Copy/Mirror a vertex parent of an object and paste it to another object,
View a vertex parent of an object to see which three vertices it's parented to.

The reason is I need to mirror an object that has a vertex parent, but I'm ashamed to say that I forgot which three vertices I parented it to and currently I'm unable to produce the same result.

I don't know the answer.  But perhaps, if the specific verts aren't so obvious, you could unparent and reparent so that then, you would know?

Hi! Thanks for the answer, but if do that, since I don't know which verts I used, I'm unable to re-parent the previous child without changing the results. I'm working on deformable and jiggly mesh so the difference became quite obvious when it's animated x﹏x


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How to create a negative space with a 3d model?
I have had some issues with cleaning up photogrammetry scans and ending up with the outside clean but lots of strange internal geometry that can be hard to get at and tidy up.
I can always clean up the scans with Zbrush Zremesher, but I would like to know how to do this in Blender.
I'm wondering if I can take a photogrammetry model and put a shape like a cube over it, and then delete my model from inside the cube leaving a negative space inside of the cube that I could then turn into a 3d model with a single sealed surface?
What would be a suitable workflow to approach this?

Try the Remesh modifier?

BTW, that negative space thing would be inverting the normals, which are data for each face that say which way it outward. It could theoretically work, but then in this case you’d just have the same problem backwards.


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How to move the median point with the character for Mixamo animation ? (GIFs included to explain)
I learned how to use Mixamo animation but I faced a problem which is for some animation, the median point (im not sure if that is the correct name) doesn't move with the character which creates many problems for me as I want to combine multiple animation in one timeline.
To explain what I mean, here is an example, I parented a cube to my character so when I move the character the cube (with the character's median point) move with it.

However, when I add this animation and play it, the cube (with the median point) does not move with the character

The armature does not move when the animation is played. Only the poses move. I don't know what you want to do with the cube, but you should parent it to a bone to make it move with the character.

thank you for your replay, actually i parented the cube with the bones to show that for this specific animation, nothing moves with the character, not the cube nor anything parented to it, that's the whole point of parenting the cube.

The gif are very low resolution, so hard to see. But it seems that the cube is parented to the whole armature (dot line pointing to the armature origin), not to a bone.

yep that's my point, how to change the position of armature origin with time?


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How to activate Clip Editor only in Motion Tracking workspace
I am attempting to use script to add a sequence of frames directly into the clip editor of the Motion Tracking workspace. I need them in this workspace so I can then track motion without having to manually change the panels. What I have so far
for ws in data.workspaces:
            if ws.name == "Motion Tracking":
                bpy.context.window.workspace = ws
                bpy.context.area.type = 'CLIP_EDITOR'

changes the Text Editor area in the Scripting workspace to a clip editor and adds the images there. It also changes the context to Motion Tracking but the clip editor in that workspace remains empty. I am still learning about Blender and its API (although I am experienced in general Python) so it was also my understanding that in order to motion track through scripting, I still must activate that workspace. Please let me know if there are any errors in this reasoning and of any suggestions you may have. Thank you!


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Uneven thickness around an oval Blender
I have been trying to create an oval that has an even thickness around it. This feels fairly simple and I don't know why I can't figure it out.
When I make a mesh->circle->scale circle to be an oval and then go into modifier-> solidify->increase thickness (click even thickness) I can tell that the oval isn't evenly thickness

any suggestions?

have you applied the scale in Object mode?

i scale it in object mode then apply the modifier, is this wrong?

don't apply the modifier, apply the scale if you've scaled your object in Object mode, to apply the scale press Ctrl A

ahhh thank you!


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Help with correctly adding an extruded cut?
I am trying to create this shape

but I am having some difficulty. I have tried to do it by first adding the loop cuts, then using Extrude Faces Along Normals (with Offset Even enabled), and then finally trying to delete the extra faces that are left, like this:

However, after doing this, I am left with only a large face that is selectable (I would expect that both of them would now be individually selectable). This is shown in the image on the left below. The only thing I can do from here is to start deleting many of the bottom faces and try to rebuild.

This seems like a lot of work, so did I do something wrong with the extrude tool? Any tips/guidance would be great.
(I don't want to use the boolean modifier, because I am trying to practice and learn how to use the other tools (extrude, etc), and get a feel for how to manipulate the mesh).

You should think the other way around and extrude the bottom out instead (AltE > Extrude Along Normals):

If you really want to work with inner extrusions, you should try the Extrude Manifold option:

I both cases you may need to correct the topology, depending on what you want to do next. To get a clean topology the best is probably to mirror and work this way:

Thanks, I see. I will try to work this way in the future. Out of interest, in my OP, at the stage where I obtained only a single face (and was expecting two faces to select), is there a command which separates those two faces where they meet at the edge loop?

You can separate faces with V (split faces) but I'm not sure it will make things easier

This is just a PS to @moonboots' answer (since, really, you want to practice extrusions, and such) .. A simpler and more freely adjustable way to make this shape may be to sweep a curve-profile down a 2D curve-path using the profile curve as the path's 'Object' bevel in its 'Geometry' panel...

Both the profile and path can be initially constructed as meshes and converted, if that's easier, and then, after the sweep, converted back to mesh for, say, per-segment adjustments, if those are needed.