text:
Adding uniform UVs on multiple objects
How can I apply uniform UV's on multiple objects/meshes (+100). It's fine with overlapping UV's
Example:

Hi :). Are you talking about uniform scale for the checker texture? You need to match the Texel Density. There are add-ons for that :))

Hi Jachym. I am very new to Blender. Really, I am just trying to apply UV's to multiple objects, instead of creating UV's for every object manually. If the UV's can be uniform (Not scaled in relation to object size) that would be great too :)

Hi :). You can simply select all vertices of all objects, and UV > Smart UV project. This will automatically unwrap all selected.

As I understand, you have to be in edit mode, to select vertices. When I select multiple objects, it's not possible for me to go to edit mode?

Hi :). Since Blender 2.8 you can enter Edit mode with multiple objects and unwrap them at once.


text:
GoZ- Blender to ZBrush - GoB
I would like to install a GoZ live link between ZBrush 2022 and Blender 3.0.
I have installed the GoB Add-on(v3_5_66)in Blender:Edit>Preferences>Add-ons.
In ZBrush I have updated >Preferences>GoZ> Path to Blender
with the relative path but I'm still getting errors.
I have followed the instructions in the installation folder but I keep getting errors on both ends.

It looks like I'm missing something and looking on the web the installation should be pretty straight-forward so any help will be highly appreciated.
Thanks a lot to any one that could help.

source: Stack Exchange

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

sort: votes


text:
Unable to rotate instances individually in Geometry nodes
I have instanced 14 triangles in a circle mesh. I am trying to rotate these independently of each other, making them point inwards into the circle, or outwards, pointing away from the middle of the circle, dependent on inputs I was planning to add later.
I don't understand why they at least do not point in a different direction using the node tree below. According to the viewer node the "Rotation instance" node should be receiving an array of different vectors, and according to my understanding, each instance should rotate the number in the array with the equivalent index.
The math might be wrong, and I may have to fix it later but one step at a time.

please provide blend file so we don't have to rebuild everything manually

I recomended to use "curve circle" node instead of "mesh circle" node, and "curve to points" node for giving correct rotation to all triangles. In the examples below you can rotate triangles inward or outward simply by changing "Y" rotation vector in "transform" node.
Example 1. All outward.

Example 2. All inward.

Example 3. Every 'N' inward. And every 'N+1' outward.

Example 4. Linear from inward to outward.

The main mistake of your node setup probably is in wrong placing of "capture attribute" node. It always should be in one line with the nodes where you are going to apply it to.

0 converts to Boolean False, and non-zero values convert to Boolean True, therefore when you do modulo 2, and you know it returns only either 0 or 1, you can pass it to Selection directly - at least until you go beyond 16777216 https://i.imgur.com/pKXzma6.png - but as long as you use float modulo, the equal node won't help with it and the result is same with this setup https://i.imgur.com/qO4lbx5.png

Since you're rotating the instances, and you haven't used the Realize Instances node, the Attribute Capture node is unnecessary. Instead, you can just use the Position node, as shown below:

You also don't need the To Degrees node, since all nodes calculated in radians, even though sliders use degrees.

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


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Texture paint effects entire solid
I'm a beginner in Blender, so forgive me if this description is simplistic or the solution is obvious.
I am trying to paint on a black image texture on the solid. The texture looks like this.

But when I make even a small stroke on the top, the whole thing turns gray with a couple of black spots at the bottom.
Before:

After:

I've asked more experienced people, and they don't know what's going on, and I can't find anything online. What's going on here?
And I guess here's some more screenshots to see if those help.

This is the UV map.

Hi. This question was put on hold because as it stands it is not answerable for lack of essential details to understand the issue. Remember only you have access to your scene, so unless you describe it thoroughly only you know your exact setup, settings and what steps you took to arrive where your are now. Please describe in detail what your issue is, possibly supported by some accompanying screenshots with the [edit] button above. Don't post a comment or ask a new question, editing will automatically put it up for review so it can be reopened.

I don't understand the reason for the Polish mask to be truthful to you. You probably have overlapping geometry with different materials. But I can't see your objects to help you. What I would do is remove the Polish Mask image and rewire the principled bsdf to your material output since you have everything there. Then since I understand you want to paint the Base Color image I would pick the base color image and paint on it. I wouldn't change anything else besides looking for duplicate objects of the anvil.
Something is clearly wrong with the material because you can see this grey anvil has a normal map. Since you haven't connected the normal map image to your output it's impossible the material you are showing to be the one we look on the top image. Because the Polish image you have connected is a simple image with no detail, no normal or anything. The anvil should look simple low poly.
My guess is this. 2 same anvils overlapping. One has the material with the polish mask you show us and one has the principled BSDF with all the images connected to the Principled BSDF like the third image and then to the output.
Next time include the whole screen please. Let's not play find the problem with as less clues there can be.


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Selecting vertices with Python only works sometimes
When I use Blender Python to loop through all vertices to select only vertices with a Z coordinate <= 0, the script seems to randomly do one of the following:

Select all vertices
Select the vertices with a Z <= 0

Does the object need to be selected a certain way in the UI or through Python before looping through the vertices to get the correct selection behavior?

The Python I am using is
import bpy
for v in bpy.context.active_object.data.vertices:
   v.select = v.co.z <= 0

The steps I do are

Import the model into the file as a mesh
Switch to Scripting view
Select the model in the 3D view or the model list
Run the script

When tabbing the 3D view to Edit Mode, sometimes the wrong set of vertices is selected like seen in the screenshot.
The current object returns the correct object when typed into the console in the screenshot.

Bmesh version of the script
import bpy, bmesh

me = bpy.context.object.data

bm = bmesh.new()
bm.from_mesh(me)

bm.select_flush(True)

for v in bm.verts:
   v.select_set(v.co.z <= 0)

bm.to_mesh(me)
bm.free()

Selecting vertices definitely works fine. You don't deselect any already selected geometry in the script though. To deselect everything, you need to deselect verts, edges and faces because they are selected separately even though that's not the case from the user's perspective. You could do that before selecting what you need:
import bpy

d = bpy.context.object.data
for e in d.vertices[:] + d.polygons[:] + d.edges[:]:
    e.select = False

or maybe
import bpy

d = bpy.context.object.data
for e in [d.vertices, d.polygons, d.edges]:
    e.foreach_set("select", (False,)*len(e))

if you want to be fancy, and more efficient(seems to be quite a lot faster).
However you should consider that using operators in scripts the way you do is not advisable. Operators are generally designed to work with user input and for scripts you should avoid relying on them. Consider using bmesh or other techniques instead if possible.

I made the same selection in bmesh in the updated question but it is twice is slow as the bpy operators from before (when measuring the time difference with time.monotonic(). Should I write the bmesh code differently to get a speedup?

Added the bmesh code that is somehow slower at the end of the original question since comment can't have code block.


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i have problem when i calculate zero faces by tool box addon
I modeled a dragon and I am preparing it now to be printable :
It selects nearly all the mesh, I do "merge by distance" is there a problem or what.
This is the method of how I applied the scale and size of the model in cm. This is the photo of that:
This is the blender file before applying the scale :blend. file

How big is the model and have you applied the scale to the object? Faces smaller than a certain threshold can also be classified as zero faces. What happens if you delete them?

I updated the question above and put the method of applying the scale and size in cm.

Since there is no manual for the 3D Print Toolbox yet, I had to consult the source script to find out how they check for the zero faces. The default cube was used for testing.
The script looks for faces that have an area less than the given threshold. When you use Blender with the default metric settings then 1 Blender unit is 1 meter. And the face areas are also calculated in square meters (m²). The threshold is the value of the Degenerated setting. The default value is 0.00010 and it's also measured in m².
Because 0.0001 m² is 1 cm² (=1 cm x 1 cm) the script actually checks for faces that have an area less than 1 cm². And since your model is 13 cm tall when the scale is applied, this is a pretty big value for testing and results in a lot of reported faces.
In the end, you probably just need to lower the threshold and adjust it to match the 3D printer's resolution in m².

where I can find the 3d printer's resolution and is there another name for it.

I solved it by applying scale to model by "scale to deltas".


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How to solve thin faces problem to make the model printable
I modeling a dragon to print it 3d now I am preparing it to make it ready for 3d printing, the problem is I don't know how to fix the thin faces problem that gives me the toolbox addon. the following show the problem:

blend. file

Hello, does it mean that these parts are too thin and won't be correctly printed?

yes, it means that.

You may want to extrude the thin faces to a thickness of at-least 0.2-0.4mm thick.

You can try a displace modifier with a low value. Add a vertex group as the modifier influence and go into weight paint and paint the nails red

it doesn't work.

Try to Fatten them https://docs.blender.org/manual/en/latest/modeling/meshes/editing/mesh/transform/shrink-fatten.html


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Shrinkwrapped image shows edges of transparent background

I brought my blender created model into Element 3D within After Effects. In Blender and Element 3D everything looks good but when I go back to my timeline and view I can see the edges of the Shrinkwrapped images on the model's face. Anyone have some troubleshooting suggestions for this?

I figured this out! You have to go into Element 3D's Scene Setup, select the image that's shrinkwrapped onto the object, scroll down in the Edit window to the Advanced section and change AO Mode to Receive RTAO. Hope this helps someone out there.

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.


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how to bake all things together and make render fast
for example, I have a room with several things inside, I switch to render view and when move mouse (to change view) it renders again which cause it very slow.
I do not want to bake every thing one by one. is there a way I can bake all at a time, and how to make it use the bake result (texture or uv map, don't know) to make render fast? (that is, only use bake result, do not calculate or calculate as little as possible).
key point is, do not want to set it one by one (there are many things in the room)
example

here is the first snapshot of the simple duplicate of this problem, there are two objects with material of different colors

here is the second snapshot, when in render view, move mouse to change view point, it will be noisy, in this simple case it is not slow, but if many objects, it will be slow, the render engine eevee is faster than cycles but still slow

then I baked two objects together with all default setting, into one uvmap image named "bake", in this step, I have to create a new uvmap all called "bake" for each object, is there a way I can set it together, not one by one?

then I have to assign the bake uvmap to each object for render view, in the attached picture it is marked as 1 and 2, if there are many objects, this will be trouble, is there a way to do it together in a time?
last problem is that there is small problem at last, see mark 3. how to improve it?

it depends on a lot of things. Yes, by baking you can make it quicker. But also by hiding things. Or less subdividing ...or....or...or. Please show us your blend file or at least some screenshots what you did with settings.

Search for Atlas texture ... Here used with SIMPLE Bake addon make it easier ... https://youtu.be/TpXPMuBKSEA

ad 3 - it is just overlapping island margin ... when Unwrap (with Smart UV) increase value for Island Margin or lower value in Bake > Output > Margin. Just a note unwrap value is not in px since it can be later any image dimension. Does link to video solved your problem?

have tried the tool in the video. it says it should have "multiple objects to one texture", but I do not have this feature in version 6.4.0

also, after bake, I have not found the way to make the baked uvmap take effect instead of the original uvmap.


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how to simulate many balls walk
I want to simulate and visualize some situation, there are many people walking inside a big room, with walls and doors. I simply model each person as a ball or a cylinder, and write python code to move it.
the question is, how can I make the model (ball or cylinder) not going through the walls and each other? that is, they can have physics collision.  I have set the feature of rigid body, active and passive, etc, not work.
some suggest is using force, but it is difficult to control.
have tried BGE/UPBGE, it is ok for one ball, but I do not know how to generate many balls which can "walk" by themselves.
snapshot, wall is passive rigid body

snapshot, ball is active rigid body

the ball will fall, but not move
video captured
if set animation, as this:
then the ball will move, but it will not fall, and not stop at the wall (pass through):video captured

can you maybe post a screen recording of your problem? That might help us help you figure out your problem better.

I think Blender is not a good tool for making such simulations. Unity, as an example, has ready to use nav mesh systems with collision detection. https://www.youtube.com/watch?v=atCOd4o7tG4

You can run the script to get scene
import bpy
from mathutils import Vector

# select and delete all object
if bpy.context.object:
    bpy.ops.object.mode_set(mode='OBJECT')
    bpy.ops.object.select_all(action = "SELECT")
    bpy.ops.object.delete(use_global=True, confirm=False)

unit_settings = bpy.context.scene.unit_settings
unit_settings.system            = 'METRIC'
unit_settings.scale_length      = 1
unit_settings.length_unit       = 'METERS'
unit_settings.mass_unit         = 'KILOGRAMS'
unit_settings.time_unit         = 'SECONDS'
bpy.context.scene.use_gravity   = True
bpy.context.scene.gravity[0]    = 0
bpy.context.scene.gravity[1]    = 0
bpy.context.scene.gravity[2]    = -9.81
bpy.context.scene.render.fps    = 60
bpy.context.scene.frame_set(1)

bpy.ops.mesh.primitive_plane_add(size=5, enter_editmode=False, align='WORLD', location=(0, 0, 0), scale=(1, 1, 1))
bpy.context.object.name = "floor"
bpy.ops.rigidbody.object_add()
bpy.context.object.rigid_body.type = 'PASSIVE'
bpy.context.object.rigid_body.collision_shape = 'BOX'
bpy.context.object.rigid_body.friction = 0.02
bpy.context.object.rigid_body.restitution = 0.9

bpy.ops.mesh.primitive_cube_add(size=5, enter_editmode=False, align='WORLD', location=(5, 0, 0), scale=(1, 1, 1))
bpy.context.object.name = "wall_0"
bpy.ops.rigidbody.object_add()
bpy.context.object.rigid_body.type = 'PASSIVE'
bpy.context.object.rigid_body.collision_shape = 'BOX'
bpy.context.object.rigid_body.friction = 0.02
bpy.context.object.rigid_body.restitution = 0.9

bpy.ops.mesh.primitive_cube_add(size=5, enter_editmode=False, align='WORLD', location=(-5, 0, 0), scale=(1, 1, 1))
bpy.context.object.name = "wall_1"
bpy.ops.rigidbody.object_add()
bpy.context.object.rigid_body.type = 'PASSIVE'
bpy.context.object.rigid_body.collision_shape = 'BOX'
bpy.context.object.rigid_body.friction = 0.02
bpy.context.object.rigid_body.restitution = 0.9

bpy.ops.mesh.primitive_cube_add(size=5, enter_editmode=False, align='WORLD', location=(0, 5, 0), scale=(1, 1, 1))
bpy.context.object.name = "wall_2"
bpy.ops.rigidbody.object_add()
bpy.context.object.rigid_body.type = 'PASSIVE'
bpy.context.object.rigid_body.collision_shape = 'BOX'
bpy.context.object.rigid_body.friction = 0.02
bpy.context.object.rigid_body.restitution = 0.9

x = -1
balls = []
for r in range(10):
    bpy.ops.mesh.primitive_uv_sphere_add(radius=0.1, enter_editmode=False, align='WORLD', location=(x, 0, 0.101), scale=(1, 1, 1))
    bpy.context.object.name = f"ball_{r}"
    bpy.ops.object.shade_smooth()
    bpy.ops.rigidbody.object_add()
    oj = bpy.context.object
    balls.append(oj)
    oj.rigid_body.type = 'ACTIVE'
    oj.rigid_body.kinematic = True
    oj.rigid_body.collision_shape = 'MESH'
    bpy.context.object.rigid_body.collision_margin = 0.001
    bpy.context.object.rigid_body.friction = 0.02
    bpy.context.object.rigid_body.restitution = 0.9
    bpy.ops.rigidbody.mass_calculate(material='Iron', density=7874)
    oj.keyframe_insert(data_path="location", frame=1)
    oj.keyframe_insert(data_path="rigid_body.kinematic", frame=1)
    oj["control_by_rigid_body"] = False
    x += 0.2

def inside_room(x, y):
    if -2.3 < x < 2.3:
        if -2.5 < y < 2.3: return True
    return False

speed = 0.05
v = [
    Vector((-1.0, 0.0)).normalized() * speed,
    Vector((-0.9, 0.2)).normalized() * speed,
    Vector((-0.8, 0.4)).normalized() * speed,
    Vector((-0.6, 0.6)).normalized() * speed,
    Vector((-0.4, 0.7)).normalized() * speed,
    Vector((-0.1, 1.0)).normalized() * speed,
    Vector((0.1, 1.0)).normalized() * speed,
    Vector((0.3, 0.8)).normalized() * speed,
    Vector((0.5, 0.5)).normalized() * speed,
    Vector((1.0, 0.0)).normalized() * speed,
]

for r in range(2, 121):
    # bpy.context.scene.frame_set(r)
    for i, b in enumerate(balls):
        if b["control_by_rigid_body"] == False:
            b.location[0] += v[i][0]
            b.location[1] += v[i][1]
            if inside_room(b.location[0], b.location[1]):
                b.keyframe_insert(data_path="location", frame=r)
            else:
                b.rigid_body.kinematic = False
                b.keyframe_insert(data_path="rigid_body.kinematic", frame=r)
                b["control_by_rigid_body"] = True

To do this, first you need to know when to hit the wall. In my case, if location[0] of the ball > 2.4 will hit the right side (depends on the wall position).
if near the wall, keyframe the "rigid_body.kinematic". Then control by the Rigid Body.

thanks for detail demo. it is helpful. however, your basic idea is to make collision (between ball and wall) by code. which could be done by blender itself? for example, there are different walls for different case...

In blender, the common way to do collision simulation is keyframe the object, see what time will collision. And then keyframe the (is Animated). I think there is not exist a convenient method to do that today in blender unlike some game engine.

when you free control the object (keyframe the object position). It cannot do the physic simulation. Otherwise, it break the laws of Physics.


text:
Curve rope around corner
Is there a simple way to curve my rope along the red line?
Everything I find on curves seems quite complex, and I just make a mess of it.

Using curves would probably be the best option for this, but as a simpler choice:
Create your rope shape out of single vertices:

Then, just go to the modifiers tab and add a skin modifier.
If the mesh is too big, go into edit mode, select all the vertices, and use Ctrl+A to resize the skin.
If you want, you can add a subdivision surface modifier to make it smoother:

Just borrow bits from your existing geometry. (If you model a lot, you learn to be lazy)

CtrlR cut a loop round the middle of your spool, if there isn't one there already
ShiftD duplicate it and P separate the selection into a new object
In Edit Mode, S scale it out about its median point a bit, Xdelete its bottom 2 edges
E Zextrude the new end vertices down in Z
.. and Header > Object Menu > convert to a curve.

You can bevel the curve in its Data tab > Geometry panel, and keep the bevel resolution down for a low-poly rope, or in the Header menu again, Edit Mode, all selected,Curve > Set Spline type to Bezier, and V set the control points to automatic to get a smooth rope... all sorts.


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Deformed mesh when applying weigth
I downloaded a Skeleton , and a helm model with another skeleton, I deleted the models skeleton, and try to put the one I want as parent, if I do this by Ctrl + P  Bones, or bones relative, then  in pose mode the helm in this case moves as intended, but when I export the file, it says it has no bones
I tried with automatic weight's and it gives me an error.
I tried with envelop weights, and here it moves but it gets deformed, because some meshes stays in place (like the decals) and the helm itself moves.
How do I fix this? I m terribly lost.


text:
Is there any way to iterate the name of output image file?
This is the command that I'm putting into console:
cd /home/ds/Documents/blender2.80/
./blender --background filename.blend --python myscript.py --python myscript2.py -o //BlenderRepository/Images/ -f 250

And on the output I'm getting a 0250.png file
So I want to get 0001.png file once I put my command in console. Then I'm closing console, and re-open it again and put the same command and get 0002.png
Is there anyway to achieve that? via console command or python

How this question is different from: https://blender.stackexchange.com/questions/146442/how-to-iterate-name-of-output-image-name-in-blender-via-python ? Take your time and explain in detail what you'd like to have or edit your question instead.

I want to know if that's possible via console @brockmann

Why not? It's the same... @cxnt

I simply want to know if that's possible, and if it is possible, I want to know how to @brockmann

@rjg I've never worked with python or blender before

@brockmann You'd have to iterate through the entire directory and find the highest number. Not sure if that is a good solution.

@brockmann yes obviously it works. The question is if it's a good idea. The currently described approach sounds far more complicated than it should it be. A single script could generate the scene and render the frames, without manually having to run the command for every single frame.

Can I get the answer if that's possible via console, not python? @rjg

Can I get the answer if that's possible via console, not python? @brockmann

@cxnt No, not purely in command line. The two thing you could do is either have a script that that setups up a scene where you have the hairstyles changing every frame and then render this as animation from console or you have a script that setups one frame of the scene, renders, changes the scene (in a loop for a given limit). In the latter case the command line doesn't trigger the rendering, the script would with a changed name on every loop iteration.

@rjg sounds like a good idea, but I don't know how to make it

@cxnt what particular part?

almost every part tbh @rjg

@cxnt Unfortunately we can't teach you python programming, that is something you have to do on your own. The python API for Blender 2.8 is documented here: https://docs.blender.org/api/current/. If you have specific questions, you can ask them on here, otherwise https://blenderartists.org/ will be more suitable.

bash: mv render_0250.jpg render_0250_1.jpg @cxnt

@brockmann That would be the third way. Add another layer of scripting by automating the command line via bash (or another python script with subprocess). Given the current level of experience I think that wouldn't really help though.


text:
How to make a solid shader in blender?
I'm trying to get an accurate RGB 255, 0, 0 color.
Render engine: Cycles
Here's my attempt, what am I doing wrong?

I've tried using different color management settings, but still pixels jump from 255 0 0 to 255 1 1.

I noticed that if you save your render as 16bit PNG instead of 8bit, photoshop will not see 255 1 1 anymore but all 255 0 0. Can you live with 16bit?

The slight deviation in color is caused by dithering. If you want to save accurate values for non-color data, then you have to:

Set Dither to zero in Output Properties > Post Processing when you intend to save an 8-bit image

Use one of the following options: Set the View Transform to Raw, disable Save As Render in the file browser or save as OpenEXR to by pass the color management. The latter is the best approach since OpenEXR can store the actual scene linear values.


text:
this principled shader node cant be shown in blender 2.78?
As you can see appears "undefined" the PBT Principled shader node from blender 2.79, and I need to use it.
Is there a way or other alternative for rendering PBR Textures with all the same input settings that this shader has?

Please keep all extraneous text out of posts. Principled shader was introduced in 2.79 and is not compatible with previous versions

It's probably a good one... but what's your reason for not using 2.79?

@RobinBetts unfortunately i cant use it in my os

What OS does not allow you to use V2.79?

@Sprad001 its complicated to explain :"(


text:
Size of text in viewport is different in render
I'm new to blender! I have a problem that I can't seem to solve.
The tracked text seems to change size when I render it, for some reason it's bigger. I don't know what went wrong. Rendered in with Eevee render engine. This will eventually be rendered as an animation. I have a screenshot:

Is there anything else I should screenshot?

Are you able to show the render vs what you have in the editor?  Is this a file you are willing to share?

Do you need the rendered animation vs what I have in the viewport display? How do I share the blender file? @Kirbinator

I manage to fix it! So I put the resolution at 65% in 1920 by 1080 and it now matches the viewport!


text:
How to use shapekeys to strech a character? How to fix Robort?
For what I want, I believe some pictures and descriptions will do best, but I apologize if the story and large number of pictures is annoying, but I don't really have an easy way to describe this otherwise.
This is Robort.
Robort is a model that uses shape keys to strech his arms legs and torso.

When Robort tries move his arms and legs using an armature like this, or in any way for that matter,

and then tries to strech, Robort looks like a monstrousity.

How do I fix Robort?

You have to animate stretching by armatures if you use a rig.


text:
Bezier with constant cross-section (GeometryNodes)
I'm trying to create a proper physics based laser beam. Therefore I have chosen to have a look into geometry nodes, outline the laser path with a bezier curve (it is going to be reflected on mirrors by 90 degree angles) and profile the laser beam with a circle. I'm facing two problems (I'm new to geometry nodes, sorry for stupid questions)

The diameter in front of the 90 degree angle changes, which is unphysical. (as of my understanding, this happens, to keep the cross section from the outer edge to the inner edge) How to tell blender, that the diameter on a straight line should be as stated? (The Bezier curve spline type is set to Bezier, the handle types of the 4 defining edges are set to vector. Including points made matters worse, resampling the curve aswell)

(Later on, the diameter of the curve has to be a function of the curve parameter to follow the cross section of a physical based gaussian laser beam, but this should be easy)
This problem is additionally arising, when animating the laser propagation via the trim curve parameter:

As the laser is focused and the same amount of light is passing each crosssection the amount ambient illumination should be constant along the path as well as the apparent brightness of the beam should be increased. As the emitting volume decreases along the curve, the emission strength has to increased as a function of the curve parameter. Unfortunately I was not able to pass the curve parameter into the strength value of the emission shader. How is this achievable?

https://blender.stackexchange.com/questions/56079/how-can-i-make-a-perfect-sweep-with-bevel-object-in-bezier-curve3d-pipe https://blender.stackexchange.com/questions/66353/how-to-make-beveled-90-degree-corners-on-a-curve-better

Thanks, but this does not the job, as I need sharp edges and not a curved version (as this represents a light beam and at the edges, it's actually reflected on a mirror, rather than "bent around") ... and sadly I was not able to use any information in these links to tackle the triming problem and the shading problem :/


text:
Blender 3.0 is not using my GPU
When I render a scene in blender 3.0 using cycles, it uses only my CPU.
I have already done Edit > Preferences > System > Cycles Render Devices, and Render Properties > Device > GPU Compute. I've also tried a clean reinstall of the latest Nvidia driver (I tried the game ready and studio drivers).
I even reseated my GPU. I also know that the issue is not with task-manager, the 0-8% GPU and 100% CPU usage I'm seeing is accurate. I have this problem in both CUDA and OptiX. My GPU is being used by every other program I have that's supposed to use it so it's not a problem with the GPU itself.
I have a 3060ti.

You're looking at the Task Manager section for CUDA usage?

No. I know task manager doesn't show GPU usage for CUDA correctly, I've used just about every system monitor available and it's always 100% CPU and about 0-8% GPU. Plus like I said I have this problem in OptiX too.

I've had this problem in one file I was carrying across different PCs.  I had to go and select CPU for everything and restart and then I was able to select and utilize GPU.

I just tried that and it didn't fix anything

did you fix it ?
I have the same problem with rtx2070 super

I had the same issue and managed to fixed it by selecting "Optix" in the Denoiser option under Render Properties.


text:
foam and bubbles particles in mantaflow just look like white points moving around

viewport screen. those particles look the same when rendered. when combined export is turned on they completely disappear. yes the particles are rendering as objects and they have a material.
heres the blend file

did you set render as object? did you gave them materials? the provided information isn't enough...so please provide blend file so we can check it out...or watch these: https://www.youtube.com/watch?v=ufgrEMggdLg

i've added more information and also the blend file

next time you add a blend file, please do file -> external data -> pack resources before uploading, so we can help you better. Thanks.

you have to set render as object and then e.g. choose an icosphere so that it will be rendered.

each of your rendered objects need to have a material (maybe change it to a plain red just to see it works and it doesn't render as white). Afterwards (when there is not plain white anymore) you can change the material you want to have (if it's then white again, your material has a problem...)


text:
Liquid simulation - wrong flowing direction
I try to make a liquid simulation but find a problem that can not fix.

As the picture shows, the liquid flow in the wrong direction and I want it to be a straight line
Here is the setting. please give me some suggestions

You scene gravity seems correct: is your Gravity in the Field Weights also a positive number?

You may want to include a reduced size version of your liquid Domain and Effector and Flows objects only.  Is the liquid flowing out of a pipe (as it appears in the first image)?

Do you have any force fields in the scene?

It's Viscosity in the Domain that you'll need to focus on.  If you disable it doesn't curl around like soft-serve ice cream and you should keep it disabled if you want something like water.   Otherwise lower this from your already low value of 0.05 (try 0.02) if you want to have a viscus liquid like syrup.  And you might want to adjust the particle radius along with.

So it is no solution to fix it if I must use Viscosity?


text:
Low FPS and Blender Crashing
To make it short, im getting low fps in the viewport, tried various tricks/options to increase the fps, but nothing worked.
The moment i try to change the pose of a rigged character, Blender goes down to like 4-5fps, trying to play an animation in the viewport also reduces the fps to 4-5.
Trying to move a keyframe in the anmation window or pressing a shortcut to move an object (r or g) results in Blender closing on its own.
Doesnt matter what kind of character model im using, it just crashes.
Crash Log:
https://textdoc.co/cUGN1Zt0pP6ke3XE
16gb ram
nvidia geforce rtx3070
Intel i7-8700 CPU, 3.20GHz
running on windows 10

How many vertices are you trying to animate?

the model that i posted the crash log has around 45k vertices

That's not that much, are you using modifiers? Such as subdivision?

No, no modifiers, also im displaying the model in solid mode, so no heavy texture or anything

yes, the LOG says that when it's trying to draw the curves, it finds an error on a graphical library and crashes. Please share your machine specs. It's most likely you need to update GPU drivers, or something related to RAM, hence you experience sluggishness on the viewport until the point of crash.

just checked, both the game ready driver and studio driver are uptodate
i listed the specs in my initial post, do you need more informations ?


text:
Animate plants growing along path as camera passes
I've created a plant object with a simple growth animation action and arranged many of them along a path in my scene. I've animated my camera moving along this path, and I would like the growth actions to trigger on the plant objects as the camera passes so that the plants grow in front of the camera as it moves. What would be the best way to do this? I've seen dynamic painting used for similar effects but as far as I can tell this can only animate the scale of the plants, whereas I would really like to be able to use it to play my full growth animation.


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Render Without Being Affected by Light
so i wanted to make a png rotate in a 3dimensional axis, i haveimported an image as a plane and keyframed the rotation, but everytime i tried to render in blender, the png color always got off due to the lighting, is theres a way to render a png that i import, without being affected by light so the hex code remain the same, and remain transparent? probably like Adobe After Effect
is there is a compositing trick or render setting that could help? I prefer eevee.
I have find an answer but this require me to use cycles, by rendering diffuse color channel and opening compositor, put diffcol to image socket in "set alpha" node and put alpha to alpha socket it "set alpha" node.

Simply take an Emission shader, plug the Image Texture into the Color. Take a Mix Shader, plug a Transparent BSDF into the first input, the Emission in the second and use the Alpha channel of the image as mix factor. Works in Cycles immediately and in EEVEE if you set the transparency settings correctly.

I have found a trick by setting my cycles render pass to a very low number and it renders quickly now!
heres the setup

The trick with the Diffuse Color output in the compositor like you've shown in your comment should work exactly the same for Eevee as it does for Cycles.
It's worth noting that if you want exactly the same color in the output render, you will need to additionally change the View Transform in the color management:

Blender normally shifts the output colors to color spaces useful for higher dynamic range or cinematic applications, but if you want exactly the same colors out as you put in, "Standard" is your View Transform of choice.


text:
Read particular edge length and save its values as UV coordinates
Need help with creation of the script which could read particular edge length of the rectangular planes. Need to recognize which length is the width (just edges pointed in x) and which one height(just edges pointed in z). These values i would like to store as the width and height variables(dimension of the plane). All planes are oriented in the same direction (width will be always x and height always z) but there are thousands of them.  Then i would need to use these width and height as the coordinates for UVs for each point of each polygon. x=width, y=height so i will get just one single point for whole rectangle.
I tried to investigate how it would be possible and i found two scripts one for reading lengths for all edges and second one for writing UV coordinates. Everything could be possible to do just in edit mode after i will choose correct UVlayer. The second script works fine for me just i need to implement somehow the recognizin of the length and height values for each rectangle.

Reading edge lengths
import bpy
import bmesh

object = bpy.context.active_object
bm = bmesh.from_edit_mesh(object.data)

for edge in bm.edges:
    length = edge.calc_length()
    print("length:",length)

Writing UV coordinates for each vertex
import bpy
import bmesh

obj = bpy.context.active_object
me = obj.data
bm = bmesh.from_edit_mesh(me)

uv_layer = bm.loops.layers.uv.verify()

# adjust uv coordinates
for face in bm.faces:
    for loop in face.loops:
        loop_uv = loop[uv_layer]
        # use xy position of the vertex as a uv coordinate
        loop_uv.uv = loop.vert.co.x

bmesh.update_edit_mesh(me)

EDIT:
I tried to implement this calculation into my code but still i dont know how can i get the desired width and length of the ractangle. In below code a wanted just simply to print these values but without success. Is there something what i missed?
import bpy
import bmesh
import mathutils

obj = bpy.context.active_object
me = obj.data
bm = bmesh.from_edit_mesh(me)
bm.edges.ensure_lookup_table()

x = mathutils.Vector((1,0,0))

for edge in bm.edges:
    edges_x = []
    edges_z = []
    v = edge.verts[0].co - edge.verts[1].co
    if abs(v.dot(x)) < .0001:
        edges_z.append(edge)
    else:
        edges_x.append(edge)
    width = edges_x.calc_length()
    height = edges_z.calc_length()
    print(width)
    print(height)
```

I would try
for face in bm.faces:
    # Compute edge vectors
    e1 = face.verts[1].co - face.verts[0].co
    e2 = face.verts[2].co - face.verts[1].co

    # Decide which is width and which is height
    if abs(e1.x) > abs(e1.z):
        w, h = e1.length, e2.length
    else:
        w, h = e2.length, e1.length

    # Assign UVs
    for loop in face.loops:
        loop[uv_layer].uv = (w, h)

Wow. That works really fantastic. Thanks a lot!!! Appreciate it.

Assuming that you have applied any rotation and scale to the planes, this code will divide the edges of the planes into those parallel to the X axis and those parallel to the Z axis. (Really, those not parallel to the X axis, but I'm assuming your planes meet your criteria.)  If you have not applied rotation and scale, then you need to vector multiply the coordinates of the edges by the object's matrix_world.
See the manual for details on bm.edges
edges = bm.edges
bm.edges.ensure_lookup_table()

x = Vector((1,0,0))
edges_x = []
edges_z = []
for edge in edges:
    v = edge.verts[0].co - edge.verts[1].co
    if abs(v.dot(x)) < .0001:
        edges_z.append(edge)
    else:
        edges_x.append(edge)

This relies on the fact that if two vectors are perpendicular their dot product will be zero.  Since we're using floating point numbers, it's not wise to do a direct comparison to 0, so we compare to $epsilon$, here, just a very small number.
Now that you have the two lists of edges you can use them in your UV code as you need them.

I've been wondering recently (due to another question based on float32 precision), how often do we actually need to use epsilon with floats. Sometimes it's hard to reason, like here it's not immediately obvious with .dot(), but for example if instead you checked if abs(edge.verts[0].co.z) - abs(edge.verts[1].co.z) != 0 then you could be sure any equal pair of values will produce 0 (I guess not absolutely sure, but is there a reason to be paranoid and assume some Python bug?). A harder question: is there a pair of 2 non-equal values that produces 0 - but if so, that's a minimal threshold.

This is an interesting problem, BTW, I need to look around if a number can be represented with higher accuracy by increasing the fraction and decreasing the exponent, and this therefore can lead to situations where 2 numbers have a smaller difference than the smallest positive float (or the closest non-zero float to 0). Probably, but it's an interesting challenge to find such pair as a proof...

Maybe we should be paranoid... :D https://answers.microsoft.com/en-us/msoffice/forum/all/subtracting-two-equal-numbers-results-in-a-nonzero/fe1d56a6-4bce-498d-95b1-8bd20eeb1e4a

if you are comparing a value to itself, where 'itself' is, in fact, the same memory location, then unless you have a Pentium with a rather infamous hardware bug, the subtraction will always produce 0. But if you compare two float numbers that are stored in different locations and may have been computed differently, as in the question, then you need the epsilon test.   I've even used computers where hardware float a * b did not always equal b * a because of an error in the design of the multiplier.

Question is how paranoid do you want to be - Can't link source straight-away, but pretty sure IEEE-754 strictly requires a subtraction of two same floats to result with 0. Another thing is, does Python currently comply with IEEE-754. C++ doesn't, but I don't know if numpy does... Not criticizing you here, just remember that on some occasion you proved to be knowledgeable on floats and trying to squeeze some of that knowledge out of you. :)

I don't feel criticized and I've certainly benefited from you taking a deeper look at my posts in the past. The reason for paranoia isn't the subtraction, but whether two numbers computed in different ways that should be analytically equal are the same floating point value.


text:
How to instance objects and set random vertex color for vertex group of the instance with geomtery nodes
I will need to help to undestand how can i skatter some default object and change randomly the vertex colour of the instances. But not for entire object but for just vertex group.
On below picture is an example what i mean. I have a cube with coloured just top face with green vertex color. I have set vertex group with just 4 top vertice and I need to create instances of this cube and change randomly the vertex color of the top face from the colour ramp colours (blue, green, red and purple). I tried something with "Store Named attribute " node but im not able to find out how to tell blender to color just top face.

Yes but there should be obviously done much more as all cubes vertices are coloured with mixture of the colors from colour ramp but i need just the top 4 vertices in vertex group will be coloured with one colour per object. I need the result will looks similar like on the second picture.

Simply switch the domain to "Instance":

And in the Shader switch the Attribute node from Geometry mode to Instancer.
Requires B3.4+


text:
Can someone help me fix the color issue in my blend?

I have a multi-part character model and after detaching parts the colors got screwed up and I can't figure out how to get them working.
When I choose MMD shading - Shadeless, the textures show properly, but they look bad due to no shading.
As such, I guess it's something to do with shading, but nothing I've tried has worked.
Any help would be appreciated, thanks.
Edit: Found something else that might help?
When I change the camera angle the ends of the arms/legs/neck all have this weird transparency with a shade inside that moves around as I adjust the camera angle.

You have checked the normals (face orientation)? The Auto Smooth option and Custom Split Normal Data can cause shading problems, too. Is there transparency used in the material? -- and what means "...after detaching parts...."? How have you detached the parts?

I'm not too familiar with normals, but I tried flipping them and I also tried Recalculate Outside and Inside. None of them helped, they only managed to make it worse by flipping the inside to the outside. As for transparency, I don't have any transparencies attached as textures. For detaching parts, I separated the arms, legs, body and head via selecting the faces and using separate to make them their own objects. Even if I rejoin the parts, the shading doesn't fix itself, so that's not the issue. Although, the shading issues are where I separated the objects into their own object.

Just to clarify, the files are .vb, thus why there are parts.

Can you share a blend file with 2 pieces that have bad shading? (google drive or  https://pasteall.org/blend/ - you need to post the generated link here after the update ) Otherwise, we have to guess a lot. If you join 2 meshes with Ctrl+J they become 1 object but the meshes are still separated. You need to merge them (M > Merge By Distance). Just saying.

I'll share the blend file with just the relevant stuff, if you need more of the model/textures let me know. https://drive.google.com/file/d/1CdHdg9exZ82QP3ocCpSwf3a-pbyL3APy/view?usp=sharing

Preparation
First, you want to check what is Material.006 and if you still need it. In Edit mode, you can use the Select button below the materials list to check where a material is assigned. In this case, it's only the edge loops.
Merging the Meshes
To join the two mesh objects select them both and press Ctrl+J. The active mesh (highlighted in light orange) will be the main object and will become the new merged object with all modifiers.
To actually merge the meshes, switch the Edit mode, select everything A, and use M > Merge By Distance to do the merge.

To check the result, unselected everything with Alt+A, hover the mouse over one merge mesh and press L to Select Linked. All visually connected mesh should be highlighted if the merge worked. (If it would fail, you need to adjust the merge distance. But this isn't needed here.)
Shading Issues (Auto Smooth + Custom Split Normals Data)
The shading issues are caused by edited split normals, so-called Custom Split Normals Data. If the Object Data Properties > Normals > Auto Smooth option is enabled Blender will use them for the shading. Imported meshes often have this extra data.
Turn Auto Smooth off to get rid of the shading issues, and use the Clear Custom Split Normals Data button in the Object Data Properties > Geometry Data section to delete the data permanently if you don't need it.

Yup, that fixed the issues, thank you very much!

We lack the information about how you model is set up to pinpoint the problem. Shading inconsistencies can have many causes like, smoothing group issues, flipped normals, blend mode irragularities, shaprness seams, intersecting geometry.

Thanks, can you tell me what I would need to show to help figure it out? The only thing I knew to try was messing with normals, so that can be ruled out.

It might be a material setting, check if the blend mode of your material is set to opaque and not alpha blend when you are using eevee. It can also be your roughness or specularity that changes the colors by reflecting your environment. Also sometimes your normal map can be set to sRGB which should be Non-Color and add a nomal map node after your normal texture. this can fix artefacts as well.


text:
'Selected' polygons are not selected?
I am struggling to learn Blender, so bear with me...
Simple idea: select one (or more) vertices.
Run the code, and all polygons connected to the vertex/vertices should be selected.
The code appears to work, in the sense that all effected polygons/faces get 'colored',
therefore - in my mind - are 'selected'.
However, the very last line shows only False's for all polygons.
I must be missing something here...

import bpy
import bmesh

#----------
def get_sel_vertices(me):
    sel_verts = [v for v in me.vertices if v.select]
    return sel_verts
#----------
# From selected vertices, select all polygons linked to those vertices (edit mode)
def vtx_get_sel_polygons(od):
    bm = bmesh.from_edit_mesh(od)
    poly = []
    for f in bm.faces:
        for v in f.verts:
            lf = v.link_faces
            if v.select:
                poly.append(f)

    for p in poly:
        p.select = True

    bmesh.update_edit_mesh(ob.data)
    return len(poly) # Number of polys
#----------

ob = bpy.context.object
print("")

if ob.type != 'MESH':
    raise TypeError("Active object is not a Mesh")

# Get editmode changes
ob.update_from_editmode()

me = ob.data

vsel = get_sel_vertices(me)

if len(vsel):
    print('Selected v: ', len(vsel))

    polys = vtx_get_sel_polygons(me) # Select all connected polygons
    print('Selected p: ', polys)

    print([x.select for x in me.polygons]) # Every select shows up as False???

The reason why it's happening is because you are tying to get the vertices/polygons data from edit mode, which is not possible by directly accessing mesh components. There are several ways to fix it:
Change interpolation mode to OBJECT and back to EDIT(brute force)
import bpy
import bmesh

def get_sel_vertices(me):
    bpy.ops.object.mode_set(mode='OBJECT') # Go to OBJECT
    sel_verts = [v for v in me.vertices if v.select]
    bpy.ops.object.mode_set(mode='EDIT') # Go back
    return sel_verts

...

if len(vsel):
    print('Selected v: ', len(vsel))

    polys = vtx_get_sel_polygons(me)
    print('Selected p: ', polys)

    bpy.ops.object.mode_set(mode='OBJECT') # Go to OBJECT
    print([x.select for x in me.polygons])
    bpy.ops.object.mode_set(mode='EDIT') # Go back

Using BMesh(cleaner)

import bpy
import bmesh

bm = bmesh.from_edit_mesh(bpy.context.active_object.data)

sel_faces = [f for f in bm.faces if f.select]
sel_verts = [v for v in bm.verts if v.select]

Using BMesh method I assume that the object will be in Edit Mode. Hope it helps!


text:
Cloth sim shirt gets stuck and unstable on characters under arms
My cloth sim shirt keeps getting stuck under my character's arm pit like this:
https://i.sstatic.net/mWxkY.jpg

Since the cloth is constantly stuck there it won't settle and the shirt won't stop vibrating. This issue only seems to happen in the underarms.
I've tried messing around with the collision distances on the body and the shirt, but nothing seems to make a difference. I also tried applying my sub surf modifier thinking more vertices would help, but nada.
What can I do to stop the cloth from bunching up like this?
Thanks in advance!!
The blend file can be found here:
https://drive.google.com/file/d/1iEDXcQhlnu-DkZcLB5veaC1lim_F3igS/view?usp=sharing

From what I see you should apply the scale and rotation of your shirt, remove the Collision, parent it With Automatic Weights to the armature, put the modifiers in this order: Armature/CLoth/Solidify, create a Pin Group, maybe lower the topology... Here is a good tuto on clothes: https://www.youtube.com/watch?v=AbyfuW5Aocg

@moonboots I followed your advice and the cloth is still getting stuck and unstable in the under arms of the character. Were you able fix this on your end?

From what I see you should apply the scale and rotation of your shirt, remove the Collision, parent it With Automatic Weights to the armature, put the modifiers in this order: Armature/Cloth/Solidify, create a Pin group, maybe lower the topology... Here is a good tuto on clothes.
I've made all these changes and some other small tweakings and here is what I get, but Blender Cloth is still really tricky to use imho:

File:

are you able to tell me what small adjustments you made for the sleeves to work that smoothly? Where did you make the pin group?

please download the file, you'll see the pin group, it's still not pefect but anyway as i said, i think it's hard to set

Sounds good, thanks so much for your help @moonboots !


text:
Solidify from midplane
Is it possible to use the solidify modifier from midplane/faces, like extrude from midplane in CAD?
I have looked through both simple and complex algorithm but there does not seem an option for it.. If anyone knows it would save a lot of time in moving and scaling. The curvatures are quite complex.

hello, could you please show your object?

I've added the image. It is the brim of the vest, but because it solidifies to one side it is not exactly in the middle of the vest anymore

Maybe ALT-E > Extrude Faces along Normals?

@JohnEason Has some potential for sure, thanks! Is it possible to do this bi-directional at once tho? Cause after extruding it to one side, it takes a hell of an effort to select all of the original faces again to extrude to the other side.. Just a lazy question.

I'm not familiar with CAD and don't really know what you mean by 'extrude from midplane' so it's difficult to know what you're actually trying to achieve. Can you add an image with an indication of what you need to your question? You might get other more useful suggestions if you do.

@JohnEason Sorry, my bad. I have added the picture from CAD from what I am trying to accomplish. In direction is shows 'midplane', and the viewfinder shows the plane/face in the middle and the extrusion going both ways.

In Blender you can only extrude a face in one direction because a face has no thickness.

Just set the "Offset" to 0 instead of -1 in the modifier.

@FFeller I don't know how I completely overlooked this option but that is it! Thank you. I don't know how to make your reply the final answer.

Just set the "Offset" to 0 instead of -1 in the modifier. –
FFeller


text:
How could I continue this selection pattern?

I tried selecting all ring loops and tweak a bit with the checker deselect but this doesn't seem to work, any ideas?

could you please share the object (only the useful part)?

You have an edge ring with several groups of five edges.
You can select the entire edge ring, marking one edge you want to keep as active edge. Then checker deselect with the following options:

Deselect four consecutive edges
Select one edge
Offset the selection of 4 edges

Thanks for the answer! On a flat plane it works like you show in the GIF. Unfortunately with the 2 edge loops in the middle it makes for 3 separate edge rings, and the checker deselect doesn't seem to understand the loop direction or something anymore.

Writing this, I could always change the edit steps ofcourse.

I've also tested on a circular mesh and it worked. could you upload your blend file?

ok, I see : this is due to the horizontal cuts, effectively. Maybe you can do it for each horizontal band?


text:
Using Geometry Nodes. How do I make each characters in a string to become specific 3D Objects?
Using Geometry Nodes, how do I make each character in a string of letters, numbers and symbols become a specific 3d object? I'd like to let the user enter a string of characters and this will help create a 3D sign with said letters.
I can't use the String to Curve node. While it is good, there are symbols I need that are not in the font and I also need control over the font geometry to keep it low poly count.

Currently the only way to process a string character by character is the String to Curve node. Even when converting a string to an array of booleans, I use this node for that reason. If some characters are not in the font, then simply use another font or create a new font for that reason. You could also replace some characters with other characters, but that's only reasonable for a low number of replacements…

Thank you. I was worried I'd need to make a new font. I've done it before a few years ago, Was just hoping I could avoid that.


text:
Weight painting problem with human head
I have a problem with weight painting the models head, even when I just use automatic weights it does this.

Whenever I move the head bone, my models face parts don't move perfectly with it, instead the mouth opens, the teeth, tongue and inner mouth move out of the head and the eyelash mesh and brows move strangely with it as well.

Looks like maybe that part pf the mesh does not completely link to the top bone? Facial rigs often have a primary bone with subordinate children bones that use copy rotation and copy location modifiers to allow motion more complicated than can be achieved by one bone alone.  This may not be the answer, but if you post a screen shot of your weight painting, we could tell.

in your case only the head bone should influence the head mesh, so probably some other bones have an influence on it, to remove any influence, select the head mesh in Edit mode, go in the Properties panel > Data > Vertex Groups, and in the dropdown menu on the right of the list, choose Remove From All Groups. Now use the Weight Paint brush to assign the head mesh to the head bone.

Not really presented as an answer, but I wanted to add these images to my comment above:
Looks like maybe that part pf the mesh does not completely link to the top bone? Facial rigs often have a primary bone with subordinate children bones that use copy rotation and copy location modifiers to allow motion more complicated than can be achieved by one bone alone. This may not be the answer, but if you post a screen shot of your weight painting, we could tell...

These images are not my work and are used for educational and explanatory purposes only.

Thanks, I found out that I had to make the whole head red in weight paint mode.


text:
View object with used texture
I'm working on a project with a lot of objects, I want to make the file a lot smaller, because its overloading my hardware.
I want to see which objects are using the selected texture. I'm in the shader editor, and I don't know how to look in my scene, and I have made a mess of the scene and materials.

Could you provide a screenshot or .blend file?

You can assign a Viewport color to your material.
That way, all objects with the same material will have one distinct color in Solid view.


text:
UV mapping shading different on each part
I was wondering if there is an easy fix for making the texture appear the same on the whole object, despite having multiple cuts in the UV map. It is imported from OnShape as object, that's the reason for this messy mesh.
All the parts are rotated the same direction but this did not help. I tried making it all squares with the add-on and cleaning up the mesh with merge by distance.
I could remodel but if anyone know how the texture can be displayed equal on all parts that would be nice!

Hi :). If the mesh is symmetrical, you could cut it in half, unwrap, and use Mirror Modifier to generate the other half

Otherwise, you'd need to perfectly overlay the UV islands (and flip some) which is waaay more complicated ;)

@JachymMichal It is symmetrical, didn't think about that.. thanks! But even on one side there are already some issues, with island that are rotated in similar directions.
yes flipping and cleaning up the mesh would be more complicated than remodel it heh, but thanks for the feedback!


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I want to make a transparent block using Blender Python in Blender 4.3
I coded several animations of transparent blocks (here shown solving a 3D puzzle) successfully in previous versions of Blender, such as 2.8.
I cannot get the Blender 4.2.1 version of bpy to produce these clear blocks.  I have followed Ron Jenson's 2020 answer but it no longer works in Blender 4.2.1.  The blocks are speckled every time.
Short answer:  it was not the code but the values in the right-hand panes Settings, Scene and Render.
Step by step I have discovered what needs fixing:  increase sampling, limit max bounces, use not EEVEE but CYCLES over CUDA, select denoise option.  I also upgraded to Blender 4.3.

Its not entirely clear where you intend to use python in this. Do you have a script you're working on that isn't working? Do you have error Tracebacks you can paste from the System Console? All this info would help get your question answered.

do you have any overlapping geometry that could cause z-fighting?

@Jakemoyo there are no errors.  The code that used to work is on my Github page https://github.com/narratorjay/j3-j/blob/main/lunar.txt.  Both render engines, CYCLES and EEVEE, produce the same results.

@Lauloque the overlapping geometry is that the acrylic block plunges into the lunar terrain.

Please do not edit the title with "FIXED" or "Solved", instead provide an answer even if it's your own question.

My apologies, I answered my own question but not in the correct manner.
Short answer: it was not the code but the values in the right-hand panes Settings, Scene and Render.
Step by step I have discovered what needs fixing: increase sampling, limit max bounces, use not EEVEE but CYCLES over CUDA, select denoise option. I also upgraded to Blender 4.3.


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Render displays solid view objects

I am running Blender 2.91.2 on Ubuntu 20.10 'Groovy' using Cycles with graphics card GTX 1070 (driver version 460.32.03, CUDA Version 11.2)
The top Viewport image (in the Animation tab) is meant to be the Material view but reflections have been rendered, the second image is under the Rendered view which displays only Solid properties.  I have not used Blender for years but it seems that selecting 'Rendered' shows 'Solid', and selecting 'Material Preview' shows 'Rendered', and selecting 'Solid' shows 'Material Preview'.
The viewports are not as important as the actual render, which I run from the command-line after closing blender.
$ blender --background 333puzzleArray-6-short4render.blend -a produces an animated solid view, uploaded to https://youtu.be/NPvrTFzeML8

I can't see which one you have selected. Is your solid the first one, material second and the rendered last one. If so then there is nothing wrong it might be because the settings from the old version to the new version has been changed. Thanks.

Thank you for asking.  The order in the Animation viewports is Wire | Solid | Material | Render, I will add another screenshot.

What is happening is that material shading, by default, uses a pre-supplied HDRi image as the world (that is why you see some trees and blue skies reflected on the glossy surfaces).
Rendered shading uses the actual settings for the scene, by default just a flat color.
You can set material view to use the actual scene lights and world.

Or you can set an HDRi to be used as environment texture on the world and that would be used for rendered view and to render the scene as well.

No improvements in the render output yet.  I have added two walls, an area light and increased the ray path bounces through transparency (the blocks are clear acrylic in real life) but the rendered video remains the same.  My Viewport shading options differ from the gif, I will keep experimenting.


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How to properly re-topo this mesh?
I am following some training about retopology. I understand why it is needed and the purpose. I am not looking for automatic retopology. I am practicing with a face, my problem is when linking meshes together (for example front to back, or around ears). I found some cue cards but they are from one side to another while in reality I need to link from multiple sides. Most times I end up with either triangles or pentagons and I am not sure  how to fix it.
Any advise is appreciated!!If you know of a good tutorial, please share it
Thanks in advance

Hello and welcome. Asking for links to resources about X is considered off topic here, asking directly about X is encouraged though. If you can rephrase your title to focus on the specific difficulties you are encountering, rather that point you to some site, please [edit] it. As it stands it is not a good fit for this site.

The important point is to know where to place loops and pole (vertex connected to more than 4 vertices) to have edge flow that works with the face
Here you have the edge loop:

Here you have area with pole:

Take a look at this:
https://www.youtube.com/watch?v=C249AnzAI40&t=271s&ab_channel=GrantAbbitt
and this: https://polycount.com/discussion/80005/face-topology-breakdown-guide
You can always google "face edge flow" to get good reference picture

If you remove one edge you can end up with this topology for example:


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how can I fix shading artifacts on my mesh?
So I crated the following mesh and after applying subdivision it looks weird.
I tried:
-merging vertices by distance
-Recalculate normals
Also I added loops to make the corners sharper but the loop does not go all the way around, it is skipping the triangle on the shoulder and the box on the bottom.
How can I fix it ?

Here is the file

It's due to n-gons. Just fix them with the knife tool, if you manage to make all your faces to quads, those should disappear

If you don't know how to do that, you can upload your file and I'll help you.

I tried adding extensions to the missing loop line it seems it made it worst. Also, I understand I need to convert the faces into 4 corner but not sure how to do that with a triangle.  If you do not mind showing it to me I would appreciate it. Uploading the file

It's because of the topology of your mesh (the faces, edges and vertices).  Blender (and any other 3D software for that matter) does not really like n-gons, which are faces with more than 4 sides to it.  You can see that some places in your mesh are missing the edge that the previous faces have?

That sometimes happen to me when I use the 'merge by distance' with too much of a distance.  To fix this you have to create edges in the n-gons to turn them into quads, you can join the vertices together (ctrl + j) or use the knife tool.
Getting great topology is fundamental for 3D artists, and investing time in learning will pay off long term, so I'll leave you some reading about topology, and recommend you learn how to use the join or Ctrl + j and Select Faces by Sides to find which faces are n-gons by selecting greater than 4 sides!  (https://docs.blender.org/manual/en/3.1/modeling/meshes/selecting/all_by_trait.html) also check the knife tool: https://docs.blender.org/manual/en/3.1/modeling/meshes/tools/knife.html
Some reading from Polygon:
http://wiki.polycount.com/wiki/Topology

There are a few things you need to consider when checking the topology of your mesh. We've already pointed out the problems with normals and non-quad faces.
In the blend files you provided, I see that you already made the faces on the bottom-right of the mesh to quad but there are still a weird shading there :

The reason for this is duplicate geometry (edges and/or faces):

Entering face select mode makes the problem obvious, you probably created those face while attempting to fix the n-gon problem.
You can just delete those three faces and refill it :

With this edge selected press F and a face will be filled automatically. Same with those ones :

After that, the bottom part of the mesh should be clean :

There is another one here :

You can clean it the same way as the others.
For the upper part, just use the knife tool (pressing K) :

After that, you'll see that it's already better :

But you still have a triangle. Depending on what you want to do, you may want to fix it, you can't do this by either creating a loopcut to have an extra vertex or by merging the two edge loops to collapse the triangle, the two should be fairly easy to do.
Anyway, I hope this helped you as the question was how to get rid of the artifacts :

Awesome!! Thanks so much!!


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Radial gradient texture not working
I added radial gradient to this 2D object and it seems just like a normal linear gradient. I used the node setup screenshotted below. How to make it look like a radial gradient?

jHG.png

Hello, what result do you want exactly, don't you want Spherical or Quadratic Sphere instead?

You're only referring to 1 dimension of your texture-space, so you're only getting 1 dimension of  variation.  Ctrl-X lose the Separate XYZ node, to give the Gradient the whole vector..  (or at least, X and Y)

@moonboots see the edited question for the gradient I am referring to

@RobinBetts let me try it. How to give BOTH x and y though?

@SledgeCR so Quadratic Sphere is not what you want?

Hi, @SledgeCR ..  Feed the X and Y of the shading-point  as parameters to your texture with Z at some fixed value. probably 0.  Scale 1,1,0 in your Mapping node, or  Separate XYZ & Combine XYZ with Z not cconnected, or Vector Math > Multiply by (1,1,0) .. or Map Range (Vector) with Z mapped to 0,0 ... etc. etc. (It looks as if your object-space Z is 0, anyway, so just plug in the whole vector) . BTW.  as moonboots has said .. 'Radial' will give you a clock-face sweep from 0-1, not a fade-from-center.

For a linear fade from object-origin, you could forget the Gradient and just use a _Vector Math > Scale of the Vector Math > Length of the Object coordinate.

@RobinBetts can you please explain the above comment in more detail? I haven't used vector math before.

'Object' coordinates are measured in Blender Units from the object origin,before any object-level transforms. (If you scale the object in Object Mode, the texture will scale with it. If you scale the mesh in Edit Mode, the texture will stay where it was)
Here are 2 ways .. one uses Gradient > Quadratic Sphere , taking as input the X and Y of 'Object' coordinates as input. Or, you could just use the length of the XY vector to the shading-point from the object origin.

In both of these examples, the Z coordinate is set to 0, which may be unnecessary, if the object measures 0 in Z anyway. The XY part has to be scaled, to fit the 0-1 range of the Color-Ramp input, one way or another.


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Glass is very black and opaque while rendering
I've tried everything I can think of, remade the glass material three different ways, asked many people, but the problem is not fixed yet. Searched on YouTube, Stackexchange and Discord but, none of the solutions work. Attaching image for reference.

Hello, maybe overlapping faces? If it's not the case please share your file

Share the file via https://blend-exchange.com/ and follow the instructions there.

Just in case, check your Light-Paths > Transmission (and Total) bounces are high enough, in the render tab..

@JohnEason I uploaded it, can you see it?

@RobinBetts Transmission - 12, Total - 16

@SledgeHammer No we can't. You need to edit your question and paste the link to the file into the question.

You could add a Transparent with mix shader and make sure to use Alpha Blend Inside the Material settings. https://blender.stackexchange.com/questions/180986/how-to-make-a-simple-plane-slightly-transparent/181003#181003

You need to enable the Caustics options in the Render panel:

Thanks moonboots, it worked! I think BlenderGuru said it saves render time...


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How can I fix my baked roughness being different from my unbaked roughness?
I baked a roughness map. I baked the roughness on a 4096 by 4096 image, I also set the Color space on the image texture to non color.
I have my samples on 16 and tile size on 4096.
I deactivated noise threshold and denoise settings.
But my baked map has less detail, Is there something I'm doing wrong? Do I need to change some settings?
I'll attach pictures of the difference and my material
Using my normal roughness (1) vs Using the baked roughness map (2)

My blend file - https://we.tl/t-sab2ontJSX
P.s for those of you who will view my blend file. I'm trying to bake the gold material, It is called "Handle and guard"
I tried to bake the material from a plane for testing purposes, as you can see in the photos, but the actual mesh in my file is a sword

To have more detail, you need to use a higher resolution image for your bake, and/or you need your UVs to use more of the image space.  However, here, making a few reasonable assumptions, there's something else happening-- probably, you're not being careful about the color space of your bake, which should be non-color for roughness.

Alright Thanks!

How can I increase the size of the UVs? I'm using the smart UV project. Do I need to increase the island margin or do I need to scale it up with normally with "S"?

To increase the size of the UVs, yes, scale them up.  But for baking purposes, don't scale them outside the UV box, and don't create overlap.  For this question, you'd be best off providing a file from just before the bake (so with the bake settings you're intending to use, with the image resolution + type you're intending to use) and then rewording your question to something more general: "Why is my baked roughness map so different from the unbaked roughness?"

Alright thanks! I edited the question and added my blend file

Well, I was wrong-- it is about the resolution (I didn't notice the huge distortion on the noise texture.)  But you're already baking to 4k, and there isn't enough room for improvement on texture usage to make it work without going to 8k or even 16k, which is unrealistic.  If your goal is rendering elsewhere, I would recommend using a different technique for roughness that doesn't rely on such high frequency detail.  For example, it bakes fine when the noise's distortion is set to 100.

alright, Thanks a lot for your help Nathan!


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Extracting Textures from model
So I am trying to figure out how to export the model textures keeping the gold, carbon, and white shaders I put on it, to a tga file. But for some reason it isn't coloring over the Image Texture I originally put onto the weapon. Could someone tell me how to extract the textures without me having to restart this whole project.
Thanks, James.
link to download the Blender Project

In the image editor (the left window on your screenshot), click on Image then Save as or hover your mouse on the image and press SHIFT + ALT + S it will allow you to save the image texture.

Yes but, I am trying to make the weapon to the left look like the weapon to the right. So I am able to extract it into a tga file for a mod pak

Which weapon on the left, I see only one weapon?

The texture for the weapon I mean, the image texture.

So the texture on the left is not the one used for the weapon on the right? If so, you can bake the textures from the object to a new image file and save it as an external image.


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Shadow is different depending on the camera position
I have this strange behavior on my project. With my camera setup, the shadow on the ground look strangly flat.

But if I move the same camera to a different place, it's ok.

I've checked normals direction, I've even try to modify the mesh but with no more luke.

I'm using a HDRi for lightning with Cycles.
Does someone have a clue?
Blend file

please provide blend file...so we can check it out

I've added the blend file so you can check. Thanks!

I would say it is optical illusion ... you just matched light direction parallel with object edge direction in Camera view ...

Seems you're right!
I tested different lights and the problem disappeared.
Thanks a lot


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Why doesn't my fluid simulation look realistic?
I created a fluid simulation for nearly one week.
A soda can that pours water into an invisible glass.
But the water does not look realistic.
Why is this?
Settings:

Resolution Divisions: 128
Mesh: Upres Factor: 2

(I'm not sure which settings are important, so I put it in the image)
By the way, is this normal?
The first frame takes some seconds to render, but starting around frame 80 it takes longer and longer.
Frame 180, for example, takes nearly 30 minutes to render.
My render needs over one day to finish and the result looks so bad.
Blender file:

Well, without knowing your hardware specifications, this is just a general statement, but yes - it is (or can be) normal that it takes longer from frame to frame. I suppose you're using a flow object set to Inflow, which means the longer the simulation runs, the more and more particles are there and the more complex the simulation becomes. You've also enabled foam and bubbles which makes it's even worse.

And how should the liquid look realistic? Which liquid glows from the inside (Emission shader?) Another thing is, depending on what kind of liquid this is supposed to be, the Volume Absorption doesn't do much if set to white, it only makes it darker but maybe not with this low density. What I would suggest is get rid of the Emission shader, set the Glass BSDF to white or just slightly tinted in the desired color, set the color you want for the liquid in the Volume Absorption and maybe increase the density. Also check Light Paths > Max Bounces > Volume, set it higher than 0.

I would also suggest you to check the scale of your models. To have realistic simulations you need to use real-life scale. I said that, tho, because I can't really guess what you mean by "does not look realistic", is it the shading, the physics, both or the bubbles?

Or for the liquid material, even better than using the Volume Absorption it would be to take a Principled Volume shader. Set the color you want as Color and play with the Anisotropy value for different results. You could also set an Absorption Color in the node.

@GordonBrinkmann AMD Ryzen 9 5900X 12 Core / NVIDIA GeForce RTX 3060 / Samsung SSD 970 SCSI / 32GB DDR4
It should be a soda. With bubbles and so on. Like this (that's the original one) https://www.dropbox.com/s/ypnyeghnxx7559j/Soda_real.jpg?dl=0 The first is another flavor

@mqbakamqbaka my can is 2x2x4,84 m but this is the Blender scale... The liquid looks not realistic enough for me. It looks a bit thick. Also the bubbles and splash look wrong.

I think that's too big. Your water looks thick because it IS thick as expected from a stream of water flowing from a 2x2x4.8 m^3 can!

The average coke can is around 6cmx6cmx12cm. If you want your animation to be realistic, you should begin with that. When it comes to physics simulations, you always need to use real world scale. If you use that big of a can, your water's gonna look like it's flowing in slowmotion and I don't think you want that.

@mqbakamqbaka I started a new project with smaller scale but my glass was not able to hold the water. It flowed
out.

I mean, of course it will flow out if the liquid is too much to be contained by the glass. But you can make it smaller, can't you?

I needed some time to just learn from the Blender default settings instead of watching hours for hours bad tutorials.
So just do this:
Create a cube. Objects -> Quick effects -> quick liquid. Then just check the "mesh" box in domain settings.
If you just run the simulation in material preview you will get:

And this is "only" a resolution of 32!!
And in my opinion it looks already great.
If you then check the material Blender gifted us:

That's pretty basic and looks already awesome.
Then you should play around with settings and tweak some settings.
Checking "diffusion" will make some more splashes:

Increase resolution in water simulations is always a good idea. But yes, it will take machine power and your time.
From left to right:
Resolution 32, 32 + diffusion, 64, 128

If you want "detail" explanation why yours doesn't look realistic, please provide blend file so we can check it out. It depends not only on domain settings, but on shader, inflow and light settings as well. And for water simulations in 99% of all cases Cycles will do a much better job than EEVEE. I my examples here are just EEVEE....
Cycles:

Another hint (no, unfortunately i don't get any money from them - not even just a cup of coffee): Flip Fluids is a great add-on which makes fluid simulations not only look better but even quicker and easier to use. Yes, you have to pay for it but i never regret buying it. And it has e.g. inbuild materials for different fluids.

Thanks for this explanation. Yes, I spent hours in YT to understand how it works and yes, my tutorial one looks good but my own one was this...so I want to understand what's wrong.  I added the file

please do file -> external data -> pack resources , save blender file and upload again so that i can see something. Thank you!

The file is bigger than 30MB so I upladet it on Dropbox: https://www.dropbox.com/s/w5m4hqh0462yx1t/Dose_v3.blend?dl=0

Hi Sven, i don't know why, but whenever i bake your simulation Blender crashes. This happens for 3.1 and 3.2. So i give up now...sorry.


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Bevel Node don't catch on all sides/edges of a basic object for edgewear
I'm trying to use the bevel node to do edge wear on object, but it doesn't work out as expected at all :
i'm using the bevel node to do edgewear on simple meshes, as Pointiness node don't work well on low poly.
However, the bevel node when used by itsef in a color ramp into a BSDF don't catch on every edge it seems ?
And when using a setup that use a crossproduct with normals, it only works on one side of the edge ?
My question is : how can i get a edge wear on ALL edges and not just a few, or only on "one face forming the edge"

I've also tried this node setup , but it only catch on one face that creates the edge...

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.

So close!
This does not work of course because the cross product of these two vectors can be negative. Convert negative to positive using abs math node:


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Dual GPU doesn't speed up rendering in Cycles
A few days ago I finished a build, including two Titan XP.
The goal was to get faster rendering, letting the gpus work as two seperate cores that render two chunks at the same to nearly double the rendering-performance.
So I disabled SLI in Nvidia Control Panel, selected both gpu's in the preferences tab and selected Cycles, using a simple scene at 4k.
The performance of the Titan XP should be circa at the level of the 2080 TI, as I saw in a few benchmarks. So two of them should be significantly faster (I read that two identical gpu's, that are not running in SLI should nearly double the performance).
But they rendered nearly at the same speed as the 2080 TI/a single Titan XP, so there was no improvement.
CPU, Mainboard and RAM shouldn't bottleneck (7980XE, 32Gb, Asrock Taichi CLX), I'm using Blender 3.0 with no add-ons and I installed the newest graphic drivers.
I tested a few different things:
only selecting one of the cards in Blender - both of them work perfectly fine
monitoring the load of the gpus - both run at 100% with SLI disabled (MSI Afterburner)
removing the SLI-bridge - changed nothing
enabling SLI - was a little bit faster than a single card, but maybe only about 20-30%
trying different tile/chunk sizes
But nothing helped.
So what can I do, to get the cards work together? What have I forgotten?
And is it possible to get the cards working on different chunks/tiles in Blender 3.0 as I described above?

As explained on rendering - No Auto Tile Size in Blender 3.0 - Blender Stack Exchange: Blender 3.0 Cycles rendering works significantly different from previous versions. Especially when it comes to tile rendering. Using tiles to force your GPUs to work on different areas might not be the way to go anymore, I'd suggest you to try without that.
Basically do not follow any trick or advice that was specific to Cycles prior 3.0 because they are effectively fit for a different render technology.
Instead, seek out advices for "Blender 3.0" and up, or "Cycles X".
Also:

I read that two identical gpu's, that are not running in SLI should nearly double the performance

That is kind of untrue. Adding X amount of identical GPU doesn't necessarily divide your render times by X. That is a "best case scenario", which you don't reach all the time. It does make things faster, but it's not as straightforward and it also depends the scene.

Thank you very much, I think that I searched in the wrong direction and just had a too simple render.
So I chose a more complex render (Spring):
Single Titan: 2:42
Dual Titan: 2:01
It was an improvement compared to the single Titan, so the dual took about 75% of the time of the single card, so in this case I got a good performance boost. And maybe I will get a bigger boost, rendering a more complex scene.
Doubling the resolution made the performance gap bigger:
Single Titan: 7:06
Dual Titan: 4:11
So it took only 58% (nearly 200% of the performance) of the time.


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How do I UV unwrap this coffee label? Without addons preferably
How do I UV unwrap this coffee label? Without addons preferably without joining issues at base.

if you want a square unwrap, try the Follow Active Quads option

Or try Cylinder Projection and Direction > Align to Object.

https://blender.stackexchange.com/questions/56748/how-to-unwrap-a-drink-can/ https://blender.stackexchange.com/questions/74041/how-to-perfectly-align-uv-coordinates-automatically https://blender.stackexchange.com/questions/78358/how-to-straighten-curved-uvs-into-straight-belt/ https://blender.stackexchange.com/questions/267513/uv-unwrap-onto-cylinder https://blender.stackexchange.com/questions/69267/uv-unwrapping-a-hollow-cylinder-sequentially https://blender.stackexchange.com/questions/39792/how-can-i-apply-textures-without-them-stretching/

@DuarteFarrajotaRamos Thanks very much your links helped me.

@moonboots Thanks very much

@GordonBrinkmann Thanks very much


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See Edges And Vertices Hidden Behind Mesh That Has A Subdivision Surface Modifier
I am watching Blender Guru's intermediate tutorial series where he makes an anvil on YouTube. When a subdivision surface modifier is applied, some of the edges and vertices are hidden behind the mesh even though I am looking directly at them in the view. So they aren't hidden on the opposite side of the mesh for example. Some solutions I've found to see them are just using x-ray mode, or by disabling the edit mode view for the subdivision modifier. But I was wondering if there was a way to bring these vertices and edges to the front of the display, without using x-ray mode or disabling the modifier in edit mode. So I want to keep the modifier enabled, but have the vertices and edges show up as if the modifier is disabled(like in the 3rd picture). X-ray mode can be a bit distracting at times since it shows all the vertices, and disabling the modifier makes it harder to see exactly how changing the vertices will affect the mesh with the modifier applied. I made this using Blender version 3.0.0.
Here is the mesh with the subdivision modifier applied:

Here is the mesh with the subdivision modifier applied, and with x-ray mode on. Now some edges and vertices that were hidden are revealed:

Here is the mesh with the subdivision modifier disabled in edit mode:

Alas, no.  Those are the only options that you have available.

@MartyFouts Alright. I'll probably disable the modifier in edit mode and switch to object mode with tab to see how it affects the mesh with the modifier then go back to edit mode.

The wireframe overlay and wireframe shading mode will reveal the modified edge loops. But the selected vertices & edges are still hidden by the modified geometry. Example: https://i.sstatic.net/ZATpN.jpg

@Blunder when you say wireframe overlay and wireframe shading, do you mean both on at the same time. And to be clear, wireframe shading is found by pressing z then selecting Wireframe? And wireframe overlay is found by clicking the Overlays drop down menu and the selecting the Wireframe checkbox under the Geometry section?

Yes, wireframe overlay (from the dropdown menu) and wireframe shading (key Z) can do this. But you use either one or the other, not both at the same time. In the screenshot you see the wireframe overlay. I often use it for the sculpt mode to see where the vertices are.

Activate On Cage mode in the Subdivision modifier. Many other modifiers have this On Cage option.

This looks like a useful tool that I may use in the future, but it curves the edges on my mesh at some places and they no longer look the same, which isn't a result I want.


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Sharp edges were baked with normal map
I was baking my normal map while I had sharp edges baked with it too even tho it is smooth in the high poly version. It seemed like it almost baked the whole topology with it also..I also smooth out my low poly version..
Here is the sharp edges I'm talking about:

Here is the sharp edges that appeared on the normal map:

Here is the .blend file:

Does anyone know how to fix it? Thank you

Can you share your blend file?

Here you go

Bake (and reference) your normal map as non-color data.  This takes care of the problem you're demonstrating.


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Does 3.0 have any limits to number of asset libraries?
In Preferences in File Paths there is a list a of folders  for the asset libraries. Is there a hard limit on how many folders you can have in it?

That's a list of folders not files. All Blend files within each folder in the list (and ones below it) will be scanned for assets. The asset library system docs are here.

Whats limit on folders

I think the answer is no, there is no hardcoded limit. Or rather, you'll hit your machine limits before the software theoretical limits. I sense you ought to be asking another question, could you elaborate on why exactly you are worried about this limit ?

i have hundreds things filled 1 per file. dozens folders 1 per source. have to mark each so wonder best way to do.

I agree with @Gorgious. There's no set limit shown in the docs. It's really a case of being sensible and not (for instance) downloading and adding every HDRI from Polyhaven to your assets in case you ever want to use one!

you know or you guess? some hard limits in prefs like undo so why not this? is not about sensible. is about many project many years mean many things collected. maybe browser not useful large collection

Well it's really hard to answer. It's like asking, How many folders can I put in one folder? ? I'm sure the theoretical source code limit is way higher than the one you'll hit with your machine. But I don't think you're supposed to have more than a few dozens asset library paths in your preferences at most. The number of folders in these asset libraries though, will be limited by your computer's capacity to read the folder contents and blend files, and the algorithm is indeed managed by the software.

Since you seem to want an authoritative answer:
Short answer:  No, there is no hard limit, because libraries are represented internally in a data type that has no hard limit.
Detailed answer:

The code that implements the preferences panel for asset libraries can be found in space_userpref.py starting at line 1839.

paths.asset_libraries is the member that contains the collection of asset libraries.

It is an instance of USERPREF_PT_file_paths_asset_libraries, a class that you can find out about by looking at the Preferences File Paths entry in the manual; where you will find the entry for asset_libraries

asset_libraries is a

Type: bpy_prop_collection of UserAssetLibrary

Comment on your underlying question:
The manual's Asset Library Introduction contains a warning:

Note that this scanning process may take a while, depending on the number of blend-files and the number of assets contained within them. Blender 3.1 will add indexing of these assets, greatly improving the speed at which an asset library can be reopened. See T91406 for more info.

In plain English, this suggests that more assets per file and fewer files per folder is probably a good idea, at least until 3.1.
I would recommend, perhaps, one file per source with all of the assets from that source in the file; but note that I haven't set up my own asset libraries yet, so that's based only on the warning.


text:
How can I get a honeycomb pattern onto these faces
Im making a tire for a vehicle as seen in the picture below and the rim of the tire is composed of a honeycomb. How can I achieve this? I have tried tessellation, Dual mesh and shrinkwrapping/boolean a honeycomb i made yet none of them give me the effect i want
Im thinking of using a rotated empty with array though im sure theres an easier way

Create your segment (front view):

Array it on X:

Create an empty at the same position, rotate it 90° on Y, give your honeycomb object a Simple Deform modifier, Bend mode, Angle > a bit more than 360°, Origin > select the empty, Axis > choose Y:


text:
Create bone model with screw cavity
How can we create such this bone model having cavities that perfectly fit with its corresponding screws? I've tried boolean function (all of its variations from intersect, difference, slice, with slicer either bone or the screw) but all I got were the hole on the surface.
By the way the bone model that I'm working with is a bone having thickness of 3 mm, not like the image below.
Image source: https://www.youtube.com/watch?v=dxUnWx-Pm3U
My current attempt is to have both the portion of the screw 1 inside the box and the cavities on the box itself.

But my attempt failed as the screw thread was all gone.
2nd edited:
My intended goal was to recreate something similar with this model coming from a paper in 2015 (doi: 10.1007/s00264-015-3106-y). .
As you can see in the green circle, there were the cavity in the bone, prepared to be inserted by the screws. I would like to create that one, but in my own bone model, which is hollow inside and has some thickness as shown here
.

Can you show your attempt? It would be easier to answer seeing what does your mesh look like

you say that bool just made holes on surfaces. In that case your bool has wrong settings that doesn't work on your model... if you insert object into another and use bool it can and should make holes with same topology as inserted object, if it doesn't work as supposed, something is wrong with either settings, your topology or face orientation

As @Luciano says, it would be good if you could show your attempt. Because I don't know what the actual problem is, if I create some cylinder (to simulate the bone), put a Boolean modifier with Difference on it and take a screw model as the other object, I get a cavity fitting to the screw. What you mean your bone is 3 mm thick, you mean it's a very thin bone or it's a hollow bone with a wall thickness of 3 mm? If it's hollow, where should the cavity be in? When you're drilling a screw in a pipe there's also just a hole in the wall and no cavity around the screw.

I am sorry I am still new to stack exchange. I just edited my post by adding my attempt. In my edited post I made that box to be assumed as the bone.

wait, did you want it to show your screw inside of the box that has no mass? I am really not sure right now... I can see that you have thread in your box but it surely won't be visible if there was no mass inside of the box, it needs to be enclosed object to make a hole

Confusing: your attempt shows a correct boolean result. Either you show the screw as in your 1st image or the hole in the 2nd, unless you're attempting some sort of x-ray view? Have you checked the viewport in Wireframe mode?

Now I'm a bit confused, too... what you write in your question sounds like you want the screw to be seen as well...? As @Luciano said, do you want some x-ray view or do you mean the cavity should be there, but invisible  because the screw is in there, too? Well, the boolean modifier doesn't delete the screw object which you subtract, why don't you simply make it visible again?

Thank you for your insights and your kind attention, I've added information about the example I want to follow as well as my bone model.

I added an answer based on your added info, hopefully someone will have a better solution :)

You state in your question that your bone model has a 3mm thickness (so hollow, like the box where you demonstrate the problem), but in the samples you show all the bones are solid. That's why you're having trouble showing both the bone and the hole.
I made a crude mockup, but that should give you something to start with:

Model the bone object (I added a Solidify Modifier just to make my sample hollow)

add the boolean modifier with the screw object(s)

hide the screw object(s) (Disable in Render) so only the bone with the holes is visible

select some of the faces to be the "window" and assign a transparent material (I added a simple Glass BDSF)

You can see that the bone object is visible, the walls are visible as a sort of x-ray view and the holes are visible (I didn't model a screw, but the basic principle is the same)

Just one addition, although it doesn't matter much for the problem: if you put all the screws in a collection you wouldn't need multiple boolean modifiers ;)

@GordonBrinkmann oh good catch, I didn't know that! I was more focused on solving the transparent bone problem

yeah well, as I said it doesn't matter much in this case anyway. But it is quite useful if you have multiple (maybe even different) cutting objects and you either do not want to join them into a single object or if they are all the same like those screws but maybe high-poly so that you would prefer instances instead of separate objects. Oh and of course you can always add new cutting objects without having to set up new modifiers - just throw them into the collection.