text:
Beginner issue with getting a Driver to refer to "self" so I can link it to many objects
I'm trying to get an object to scale with its distance to another object, so I can then link the driver to the rest of the 639 objects in the collection.

I need it to somehow refer to itself, rather than explicitly selecting the object, so that when I link the driver, each of the linked objects will scale individually with their own proximity to the sphere. The intention is for each of the hexagonal objects to scale down when the sphere gets close.
In this thread, one answer says that if Use Self is checked, I can do the distance measurement in the expression itself if I use Single Property and use the sphere's matrix.world as the Object, but matrix.world isn't accepted when I try this.
In addition, is there a way I can get the driver to control XYZ scale so I don't need to use 3 drivers?
If I'm going about this in the wrong way I don't mind restarting the project.
Thanks in advance.
Attaching my blend file as requested. In this file, the driver is working correctly, but that's by specifying icosphere.083 as Object 2. I need it to work by somehow referring to "self" or "this object", so I can link the driver to other objects and have it work per object.
https://drive.google.com/file/d/15irt899Fqtbtfo_iWR2t4CbLpn6CDl5t/view?usp=sharing

Hello ! It's matrix_world and not matrix.world are you sure you used the correct expression ?

matrix_world is also not accepted in the path field: https://i.imgur.com/i1mOpJc.png

can u provide blend file? then i would check it out

I've added a link to the blend file in the OP.

I noticed in your file that you had had a go with Geometry Nodes.. so as a side-note, this would be a possible arrangement:

The Length of the 'Relative' (i.e. owner's Object-Space) Location of the Object Info target is the distance from the GN-modified object-origin to the target object-origin. You can use some function of that for object-level proximity effects:

Oh wow. I feel bad for Chris now. This actually suits me better than the script solution, because I can apply this to other things without feeling like I'm messing with powers beyond my ken. I hadn't fully tried to make it work with GNs, because I thought I'd need an individual GN for each hex. Now I love GNs even more than I already did. Thanks! I still need to learn scripting :P

you can use this script:
import bpy

# two sample functions
def calcDistance(object):

    location2 = bpy.context.scene.objects["AssaultSphere"].location
    print("loc2", location2)
    location1 = object.location
    print("loc1", location1)
    distance = (location2 - location1).length

    print(distance * 3)

    return distance

# Add functions defined in this script into the drivers namespace.
bpy.app.driver_namespace["calcDistance"] = calcDistance

driver settings:

result:

That is excellent, and works very well. Thank you very much.
I can understand most of the script, but it's beyond my ability to arbitrarily replicate. I knew this would end up with me having to learn Python, but didn't expect it so soon.

Glad I could help.

I just can say from my personal experience: you can do a lot just with Blender - but you can do a lot more with python…‼


text:
I am trying to texture paint but the object keeps showing purple although it has a material of its own
here is the blend fileI want to add a blush to the cheeks of this emoji, so I decided to try texture paint. I used the SMART UV project but it keeps showing purple and it doesn't paint. If on the other hand, there is another way to add the[ blush to the emoji, it'd be great to know. Thank you.

your image shows a "multiplication" symbol, so maybe saving your image file would help?

Hello please share your file (just the important part) so that we understand what's missing: https://pasteall.org/blend/

https://pasteall.org/blend/62016e14e0284467a43d6a4ccc4b9e47

You are editing a stored image that you didn't include (pack) with your file:

And this is part of the problem that we'll return to (#2 below).
Problems:

you had no vertices assigned to the material "Blush". In EDIT mode, I went to your objects Material properties tab, clicked on Material (yellow), click Select, then clicked on Blush and clicked on Assign.  You can only have one matl at a time assigned to a vertex, you'd want to first fill the Blush canvass with your background/base color or load the image assigned to the face, and then "blush over it".

I selected Generated image (which I packed into the file for my example), and was able to paint.

Now you can paint inside blender in Texture mode or in the Image Editor (in Paint mode):

It worked. Thank you so much

source: Stack Exchange

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

sort: votes


text:
How do I give an object a fur material?
I want to give the eye ( the part shaded in black) a fur material . I tried using the hair shader but it did not work.

I think you misunderstood the hair shader. It should be used together with particle system -> hair
then it could result in:

make sure to check children -> "interpolated" or "simple" so it will look better if you render. But still quite quick in the viewport.
longer hair:

Thanks a lot. It worked

you are welcome

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


text:
No vertices on skin modifier
I added a skin modifier. I can't see or select the vertices. What's wrong?

Presumably there are only two verts. One will be at the centre of the 3D cursor and the other is visible at the top of your edge. Upload your file if you want someone to have a look.

I've uploaded the file

When modifiers generate geometry, you can't access the generated geometry until you have applied the modifier.

Do I apply both the skin and subdivision modifier?

Try and see what's better for you.

Err. You certainly can access the two verts in @Martin's file! I've just downloaded his file and selected both of them without applying any modifiers and can move them around without problems

Thanks a lot. Figured it out later


text:
normal map with only one side does not work for me like this
I have a dragon model downloaded from the internet whose normal map shows only one side of the model with uv, I tried to do the same since painting the textures like that is easier, but when I make the normal map it doesn't work the same way and the shadows don't they are as I would like, I was wondering how they achieved this and if it is possible with blender.enter image description here

the model is of a dragon from skyrim and I find it fascinating how they managed to do this, how do I do the same?

This is how it looks when I try the same thing

Hello, are your UV islands correctly placed? Is your Image Texture with the normal map set to Non-Color instead of sRGB?

Mostly, you don't hand-paint normal maps.  You should think about using a bump map instead if you want to hand-paint.  Normal maps will usually be generated from other data, like from a bump map, or from a high poly sculpted mesh.

I don't paint the normal maps by hand and I have the map set to non-color, I generated the map using the bake from multiress tool, but it doesn't matter since i solved the problem even though I don't know how, and I don't know why it happened


text:
Why is my boolean modifier ignoring the top of this shape?
I've stacked boolean on top of boolean on top of boolean to get to this shape:

However, there should be some other cutouts on top, and it's ignoring them...

Sharing the blender file... https://gofile.io/d/Bl8FGQ
not sure if someone can figure out why there's no nice cutouts.
What I want is to have a perimeter like the bottom, but on top... so there should be tiny holes up top, I would think?

That is possibly the worst most error prone way to achieve this. https://blender.stackexchange.com/questions/40997/how-can-i-make-a-hexagonal-grill https://blender.stackexchange.com/questions/67334/how-to-turn-my-honeycomb-pattern-into-the-sphere https://blender.stackexchange.com/questions/223591/honeycomb-boolean-around-cylinder

...Thanks. I used the second way in the first link you sent... because it seemed a lot faster and easier. I'm still a beginner.

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.


text:
Can Particle Grass derive it's color from underlying Image texture?
I've been following this tutorial to create a nice grass feel.  https://www.youtube.com/watch?v=46yAuZ1GBb4&t=68s&ab_channel=KristofDedene
I found it a bit limiting though,  trying to further design the grass shapes using the hair particle attributes. Though the beautiful thing is that these particles grab the underlying texture.
I'm wondering if it's possible to have an instanced grass clump, grab the color data from which it's respective particle emerges from the underlying image texture?
Quite new to the arena of texture/shading and such, so if someone could point me to a specific tutorial that might help, or describe the process that might solve this, that would be most appreciated!
Thanks,
Dave

Your instanced particle needs the emitter object referenced in the Texture Coordinate node, and then check the From Instancer option.
This is Cycles where everything is handled by the underlying emitter's UV map.

It's doable in Eevee as well, but from what I'm experiencing right now the setup is not friendly, you'll have to use Object Coordinates and position it for the specific object you're making.

Awesome, that solved it. And I'm especially glad it works in Eevee.  I'm not sure I totally understand why, but when adjusting the mapping node to fit the texture for eevee rendering, the XY scale and translate values we respectively -.05?  In any case, thank you for your time, answering my question.


text:
alpha channel and RGB channel aren't separating correctly

i have a test image texture here,
i painted on it with random colors and erased alpha as you can see on the top left corner in the image editor.
in the shader editor [bottom left], when i connect the image to a viewer node or the principled shader i get the colors plus the alpha as shown in the left half of the whole image,
but on the right half when the alpha output is hooked to some node i get the right view of my image without the alpha.

I am very confused, why are you addind Alpha value to Math node?

What do you mean by "the RGB colors appear correctly"? On the right side there is no alpha information, it's completely opaque. So if you don't want any alpha transparency, why is there alpha information in the image?

sorry for the confusion , I'll edit the question to more clear

hope its clearer now

@gordon-brinkmann its the same image ,same result, the only difference is that the alpha output is busy with another node

Hmm if all else is exactly the same, this looks like a bug and should be reported to the bug tracker

@Gorgious I'm quite sure you're right, this is a bug.

EDIT: This answer was referring to the first wording of your question, where it sounded like you were taking the preview on the left with black areas as incorrect display, and the one on the right without black areas as incorrect display. Now it seems you're aware that the black areas have to be there - then it's simply a bug.
Old answer:
What you have done is setting the Blend type of the brush to Erase Alpha and painted some strokes - the ones appearing in black on the left image and transparent in the Image Editor window. This is because Erase Alpha paints black in the Alpha Channel, meaning the white parts where the image is opaque will be painted black, so the image is transparent in these areas.
The Image Editor displays transparency correctly. Your 3D Viewport however is set to Material Preview - in this mode transparency appears black, because the default setting of the preview cannot display transparency.
Somehow (and this might be a bug), plugging the Alpha output into some other input (doesn't have to be a Math node) makes the Material Preview ignore the alpha information. But this is actually not "correct" as you think, because there is an alpha mask which is now ignored.
You can tell that the behaviour of ignoring the alpha mask when plugging into some other node might be a bug, because deleting this other node doesn't bring back the alpha information, you have to re-plug the image into the viewer node.
This happens only in Material Preview mode, if you switch to Rendered View, the areas remain black - which is correct, since the texture is transparent there, the color informations of these areas are not visible. Because you don't have a Transparency BSDF mixed in with the alpha, the black areas stay opaque.

yes a a bug is more likely , i thought the alpha channel overlays as 4th layer , but like you said in the first answer, it just paint black .thanks.

@wafi Well, the colors are in the RGB channels, so painting in the alpha channel cannot overlay the colors. And it only paints black in the alpha channel, it actually paints transparent and would show underlying textures - but you have no underlying texture there.


text:
Blender face problem
I'm new to Blender and having problems creating a face from the following geometry:

As you can see, the face has been created (by clicking inside the thin region between the 2 geometry loops) but I only want the face to be the outer surround, not the interior (It's going to be the wooden surround for a snooker table)
All the geometry belongs to the same object so I'm guessing that the problem might be that the inner loop has a break in it somewhere. The trouble is that I can't find it. Is there a way to get Blender to highlight where the problem might be? Or am I missing something with faces? Maybe they can't be used to form a loop like this?
Thanks for any help.

Simon

select the face and X -> delete face?

Thanks for your input Lukas. I'd tried that but the problem was in then reselecting just the outer loop. K A Buhr nailed it in the post below. Your time was much appreciated though. - Simon

Blender doesn't allow a single face to have a hole like this.  (Technically, a face must consist of a single sequence of distinct edges connected end to end in a loop.  Your desired face has two such sequences, one for the inside and one for the outside.)
What you'll need to do is introduce some extra edges -- a minimum of two are required -- that connect the outer loop to the inner loop and then create multiple real faces to represent your single desired virtual face.
A fast way to do this (though it uses more interior edges than strictly necessary is):

Delete all the faces from your object.
Select all the remaining geometry (both the inner and outer edges),
Select Edge -> Bridge Edge Loops

This will add multiple edges between all the inner and outer vertices and fill them all with faces.
A slightly more tedious method that results in the minimum number of interior edges (two) is:

Delete all the faces from your object.
Select a pair of vertices, one on the inside loop and the other on the outside loop, ideally in close proximity to each other.  Use F to join them with an edge.
Select another pair of vertices somewhere else (e.g., on the opposite side of the shape) and join them with an edge the same way.
Use whatever method you can to select all the vertices for one of the two portions of the outer loop and the corresponding portion of the inner loop, selecting half your total shape.
Use F to create a face, filling half your desired face.
Repeat step 4 and 5 with the remaining vertices (plus the four shared vertices that are part of the added edges), to fill the rest of your desired face.

Many thanks. This solved my problem and the question is closed.


text:
2 same rigs, different poses, but animation acts weird when trying to merge all into 1 rig
This may be hard to explain, but I've had this problem for quite a long time now.
I have 2 rigs, and what do they have in common? They're the same exact rig, but here is where the problem lies. When I switch the run animation to the walk animation, the walk animation moves weirdly. This is because both rigs have a different rest pose. Here's another thing, they were exported from C4D. So, I am not sure if it's a setting that is affecting the armature settings. Also, the mesh is also affected with the armature to be shaped as the rest pose of the rigs, so there is no T-pose on those meshes on the rigs.
You can see on the forth photo that I am in edit mode, and that its rest pose.
I do have the rig with it's original T-pose, so I don't know that is needed for this case. But if anyone can help me find a solution to this, that would be great because I have other rigs that have the same problem.

UPDATE: IT WORKED! The new constraint method below turned out to work as intended than the Copy Global Transform! Just follow the instructions, after doing the script, export as FBX, re-import the FBX,find and link the animation that works perfectly on the rig that has the T-pose, delete the other rigs except the one with the T-Pose, delete the unwanted animations, repeat for other animations, and that's it!

If your 2 armatures have a different rest pose, you won't be able to swap the actions

I already know that. That doesn't answer my question...

You also say that the mesh is not aligned with the armature, but even if you fix that by changing the armature or the mesh default pose, it won't fix the fact that you can't swap the actions

A thing that you could do is changing the default mesh pose so that it matches the default rest pose of your armature

How can I do that if you say that?

You mean how to align the mesh with an armature rest pose? You can use the Pose brush in Sculpt mode for example

or you can use its current armature to align its shape to the other armature's rest pose, then apply the armature modifier

Here's the thing, the bones go in a different direction from the animation if I re-shape the position of the bones.

I'm not sure what you've tried, you have different problems here, you need to tell precisely which problem you want to fix, I may be wrong but I doubt iyou'll be able to swap the actions as the 2 armatures have a different rest pose and the actions are made for each armature

I recently tried using a script from here https://blender.stackexchange.com/questions/74672/two-armature-two-rest-pose-fixing-animations, but all it did was overwrite the other rig to be the same as the other rig, along with the animation being overwritten.

Please consider sharing your file so that we can try things out directly in your particular situation. Make a file with just the rigs and models (remove the textures for speedy download) and sent id on Blend-Exchange and [edit] your post to add the provided download link.

@L0Lock the download link is posted above

Two methods I know: Copy Global Transform addon, and Constraints.
Copy Global Transform
(doesn't seem to work in your case, but could in others)
If the armatures have the same bone names and dimensions, you could try using the Copy Global Transform addon.
It is shipped with Blender, you just need to enable it via the menu Edit > Preferences > Addons tab

The addon's UI will be located in the viewport > Sidebar > Animation tab > Global Transform panel

Then, select both rigs in object mode, ↹ Tab into pose mode, and select all the bones of one rig. Copy the pose. Then select the other rig's bones and paste using the addon's panel. Hopefully it pastes the pose correctly, and you can repeat for each frame.
Constraints
In the armature you want to copy the animation in, you could select each bone one by one in pose mode and add a Copy Transform constraint targeting the source armature's same bone.
Then, you can use Pose > Animation > Bake Action with visual keying and clear constraints ON:

Adding constraints to each bone can be time-consuming, so here's a script that does it for you.
Select the armature you want to copy the animation to, and ↹ Tab into Pose Mode. You just have to paste the following script in the Script editor, make sure to write the name of the armature you want to copy from in the ARMATURE_SOURCE variable lines 4 between the simple quotes at the end. Here I used 'Armature'.
Then run the script with ⎇ AltP.
import bpy

# Get references to the 'Armature' and 'TPose' armatures
ARMATURE_SOURCE = bpy.data.objects['Armature']
ARMATURE_TARGET = bpy.context.active_object

# Initialize a count for bones with no equivalents
no_equivalent_count = 0

# Loop through all bones in 'ARMATURE_TARGET' armature
for bone in ARMATURE_TARGET.pose.bones:
    # Check if there's a bone with the same name in 'ARMATURE_SOURCE'
    if bone.name in ARMATURE_SOURCE.pose.bones:
        # Remove all constraints from the bone to avoid redundance and potential issues:
        for constraint in bone.constraints:
            bone.constraints.remove(constraint)

        # Create a Copy Transforms constraint and set the target bone
        constraint = bone.constraints.new(type='COPY_TRANSFORMS')
        constraint.target = ARMATURE_SOURCE
        constraint.subtarget = bone.name  # Use the same bone name as the target
        print(f"Constrained '{bone.name}' to its equivalent in '{ARMATURE_SOURCE.name}'.")
    else:
        # If no equivalent bone is found, print a message and increment the count
        print(f"No equivalent bone found for '{bone.name}' in '{ARMATURE_SOURCE.name}'.")
        no_equivalent_count += 1

# Print the count of bones with no equivalents
if no_equivalent_count <= 1:
    print(f"Number of bones with no equivalents: {no_equivalent_count}")

This constraint method did the trick! Thanks @L0Lock!


text:
CGMatter Facial motion capture tutorial - script error
I am working on the facial animation following the cgmatters tutorial: https://youtu.be/uNK8S19OSmA
Everything works fine except script from the end of the video. I have more than 200 trackers so im getting python error. Code looks like this:
for value in range(1,iter):
if value == 1:
bonename = “Bone”
elif value > 1 and value < 11:
bonename = “Bone.00” + str(value-1)
elif value >= 11 and value < 100:
bonename = “Bone.0” + str(value-1)
elif value >= 100:
bonename = “Bone.” + str(value-1)
bone = bpy.data.objects[‘Armature’].data.bones.get(bonename)
bpy.data.objects[‘Armature’].data.bones[bonename].name = ‘Bone’ + str(value)

It should rename my 215 bones but im getting messege:
`"line 63, in
KeyError: ‘bpy_prop_collection[key]: key “Bone.99” not found’
full script:
#CGMatter Face Mocap Script
import bpy

iter = 1

#rename trackers
FaceTrackers = bpy.data.collections.new('FaceTrackers')
bpy.context.scene.collection.children.link(FaceTrackers)
for trackers in bpy.data.objects:
   if trackers.type != 'EMPTY':
       continue
   else:
       iter = iter + 1
       FaceTrackers.objects.link(trackers)
if FaceTrackers:
    for i, o in enumerate(FaceTrackers.objects):
        o.name = "Tracker%d" % (i+1)

#face mesh setup
bpy.context.scene.frame_set(1)
for obj in bpy.context.selected_objects:
    obj.name = "Head"
    obj.data.name = "Head"
bpy.ops.object.transform_apply()

#trackers with depth
for value in range(1,iter):
    selectname = "Tracker" + str(value)
    ob = bpy.data.objects[selectname]
    bpy.context.view_layer.objects.active = ob
    bpy.context.object.constraints["Follow Track"].depth_object = bpy.data.objects["Head"]

#add armatures to trackers
for value in range(1,iter):
    selectname = "Tracker" + str(value)
    ob = bpy.data.objects[selectname]
    bpy.context.view_layer.objects.active = ob
    bpy.ops.object.armature_add(enter_editmode=False, location=ob.matrix_world.translation)

#select armatures
for bones in bpy.data.objects:
   if bones.type != 'ARMATURE':
       continue
   else:
       bones.select_set(state=True)

#join armatures in correct order
bpy.context.view_layer.objects.active = ob = bpy.data.objects['Armature']
bpy.ops.object.join()
bpy.ops.object.transform_apply()

#rename bones in armature
for value in range(1,iter):
    if value == 1:
        bonename = "Bone"
    elif value > 1 and value < 11:
        bonename = "Bone.00" + str(value-1)
    elif value >= 11 and value < 100:
        bonename = "Bone.0" + str(value-1)
    elif value >= 100:
        bonename = "Bone." + str(value-1)
    bone = bpy.data.objects['Armature'].data.bones.get(bonename)
    bpy.data.objects['Armature'].data.bones[bonename].name = 'Bone' + str(value)

#parent face to bones
bpy.data.objects['Head'].select_set(True)
bpy.data.objects['Armature'].select_set(True)
bpy.ops.object.parent_set(type='ARMATURE_AUTO')

#parent bones to trackers
bpy.ops.object.posemode_toggle()
for value in range(1,iter):
    trackname = "Tracker" + str(value)
    bonename = "Bone" + str(value)
    bone = bpy.data.objects['Armature'].data.bones.get(bonename)
    bpy.data.objects['Armature'].data.bones.active = bone
    bpy.ops.pose.constraint_add(type='COPY_LOCATION')
    bpy.context.object.pose.bones[bonename].constraints["Copy Location"].use_z = False
    bpy.context.object.pose.bones[bonename].constraints["Copy Location"].target = bpy.data.objects[trackname]
    bone.select = False
`

I have also attached blend file:
https://drive.google.com/file/d/17lD4iZkZZH5eJbxSrWrC3aMeLDhYtLkK/view?usp=sharing

Hi. Please post the full script and ideally your blend. Looks like your bones are not named properly. Also at a first glance: the script from the tutorial: https://youtu.be/uNK8S19OSmA?t=1413 looks pretty bad, a lot of data is hardcoded for whatever reason... which can cause the error as well.

hi! thanks! i have edited the post

A quick and dirty fix: https://pasteall.org/L38c/raw Please test and let us know whether it works or not. I will revise the script if I have the time, doesn't look like python rather bad javascript code to me.


text:
material not appearing transparent. what is my mistake?

now looking like this

my settings

supposted to look like this

Can you post a link to the "chiffon.png" texture itself? If the .PNG uses alpha transparency to achieve its effect, you may need to use the "Alpha" output socket instead of the "Color" output socket on the Texture Node for some of the transparency blending, but this would just be a guess without seeing the .PNG file.

I just added png

I just tested it out, and your node setup works perfectly on my end. I get a sheer, blue chiffon when I render, which is transparent between the "threads". I did notice that your Viewport Shading is set to "Material" instead of "Render", and I don't think the transparency will show up in "Material" view. Does this issue still occur when you render?


text:
Two origin points for simple deform

I want to bend a beam keeping the endpoints rooted on the x-axis but curving upward on z-axis. I tried to set two origin points on each end of the beam but was unsuccessful. Is there an alternative way around it? Unsuccessful in animating it as well.

hello, could you please show a picture of what you're trying to achieve?

please show us at least a screenshot with "what you have" and "what you want to have"

The first picture is the original layout. The second is what I am getting and the third one is how I want it to be.

@Edgel3D thanks for the videos. They are exactly what I need. But I am still looking for the process to follow to do the needful. Can you help me out with that?

I'll put an answer together.  Any particular method you favour? (so I don't have to do all 3) The curve is the easiest, but it won't stretch the beam, and one end gets dragged back the more you bend it.  The Laplacian would be the hardest to explain for the inexperienced but it does anchor the ends firmly and allows the beam's mid-section to stretch no matter how far it's pulled up.

@Edgel3D: I think Laplacian would be the best for my project. Thanks in advance :)

A metal or wooden beam is to be stretched up in an arc with it's ends firmly clamped.
(Blend file below)

Notes -
A lot of problems can be avoided when using the Laplacian modifier by ensuring the mesh object(s) it's going to be used on and those associated with it, are all scaled to 1. (CTL-A)
Similarly, hooks used to deform it should also have a scale of 1 "applied". (CTL-A)
Additionally, ensure there is plenty of mesh subdivision in those areas to be deformed and even more in those that are to be anchored.  They may not anchor properly if there aren't.
.
The principle difference between 'Laplacian Deform' and the Curve modifier, is that with the former, nominated areas of mesh can be included in a vertex group, and those areas clamped at a location no matter what's happening to the rest if it.
Those areas not exempt (clamped) can be deformed smoothly and independently.
.
If the clamped ends are moving a little, it means you haven't enough subdivision at those ends.
The 'Repeat' slot may help but usually it's a matter of subdivision..
-===============-
Procedure -
Lay the beam (a stretched cube?) flat along the X axis.
In ORTHO WIREFRAME view, view from the front (numpad END key) and in Edit mode, box select only the horizontal edges and subdivide generously.  If you need more than 100 subdivisions, subdivide once at first with keyboard 'W' so you have a new vertical edge highlited at the center.  Deselect that with 'A'.
In Edit mode It should look like a loaf of bread sliced at the middle.
Re-box-select the HORIZONTAL edges in each half but NOT the vertical slice at center.
Subdivide this time with a figure of say 64.  This will give you 128 subdivisions in all which is usually enough for smooth curvature.
.
Now for those clamped ends - but first, save the file.  You may need to come back to this point.
Select those vertices that are to be exempt (the anchored sections) and include those in a new 'Vertex Group', thus -

As you need to pull the beam up at it's center you will need to exclude the section you want to grab also.
With the ends still highlited, box select the center vertices you want for the 'handle' so you have the clamped ends plus the center vertices all highlited.
Press 'Assign' once more to include all those selected.
(you can check this by pressing A, then in the Vertex panel, press "Select".  Only those vertices assigned will highlite again)

.
The ends may well want to move a little with the current subdivision, so the assigned (horizontal) edges ends ----> at the ends only <---- can be further subdivded x 4.

In Object mode, select the beam and give it a 'Laplacian Deform' modifier.
In it's  "Anchors Vertex Group" slot, select the Vertex Group just created and press the 'Bind' button.
When it changes to 'Unbind' is means that binding is complete.
The beam is now under control of the Laplacian Modifier.
In order to pull the center vertices up, a Hook is required so it can be animated with ordinary keyframes.
In Edit mode, select all vertices in the created Vertex Group and then deselect those at the ends so only the center group is highlited.  It's done this way because the hook MUST ONLY operate on those center vertices that are included in the vertex group.  (If you've selected extras, you can end up with odd effects)

Use CTL-H to add a (New) Hook Object.  An empty will appear.
Goto Object mode, select the Hook Empty and resize (scale) as required.  The beam's center will be throttled but that's fixed by using CTL-A and selecting  "Scale".
The beam should return to it's former self.
Go to the Modifier list and push the Hook modifier panel up so it's above the Laplacian entry. (use the triangular buttons)
.
In object mode, select the hook and drag it up and down.  The beam should curve smoothly with it's ends clamped to the ground.
-=================-
It may eventuate at some future time that the beam or any 'lapped' object for that matter needs to be attached to a moving vehicle, or simply at rest at some odd angle, possibly making it harder to setup the modifier and Hook.
The solutuion is to do as above, and once complete, give the whole thing a common parent.
i.e. the beam and hook become children of the master parent.

With that established, disable selection of the beam and hook in the Outliner, so you can only drag the parent around.  That parent can be a child of a vehicle etc.
The assembly will follow as one unit , along with it's local animation, clamped ends and all.

Thank you sooooo much!

You're welcome @Shal - any problems, leave a comment here


text:
lighting issues
I'm using a camera to take images in Blender, but the lighting in the scene doesn't remain consistent with the sun light I set up.  It changes based on where the camera is located so that areas that shouldn't be lit are.
eg:

Moving the camera forwards:

moving the camera to the another side of the building

How can I fix this lighting so that it uses my sun light, and just lights from one direction, regardless of the viewport or camera angle?
Please ask me if I've not been clear enough to clarify. I'm not sure how else to communicate this.
Here's a link to my blend:
https://drive.google.com/file/d/160TOtAbp_f4_WpkmAm3NanIdaYd7dAnF/view?usp=sharing
My shaders outside the grass are set up with some varient of this:

Are you using camera coordinates or any extremely strong normal maps in these shader node graphs?

Sorry for taking so long. I have used a colour ramp to get a flat shading, using a constant ramp.

This is interesting, but not something I've seen before.  If you can [edit] your post with more information maybe someone can help.

Sure Ill add in some shader nodes and the blend file

If anybody wants more info please ask me some questions, im not really sure what additional information I could provide.

You are using a large sphere around your scene to cast the sky color, and this shadow on the ground is the sphere's shadow.  It is, for some reason, only visible a certain distance out from the camera.
In any case, you can select the 'Sky' sphere, go to the material settings and set the Shadow Mode to None and the issue is solved.

Thank you Allen!

No problem :) It's a really interesting aesthetic


text:
How to stop my transparency shader changing its visibility based on the observation angle
I'm trying to add a semi transparent colour over an eye socket in my anime style model. I hocked up a transparent bsdf to a mix shader with a value connected to the fac input. In the preview render the sphere has a hole in the bottom and as a result causes my mesh to only display correctly at select angles. How can I fix this?

Probably, use alpha hash instead of alpha blend.  It's probably unsure of whether to draw this in front of or behind another alpha mesh.  But, possibly, it has to do with z-fighting between two meshes in the same or nearly the same position.

I already tried that, it greats this horrible grainy textured shadow, I need it clean. There's nothing near the shade mesh, other than at the edges in the socket rim.

You can use more samples to improve the look of alpha hashed.  Otherwise, you can figure out what alpha blend texture it's competing with, and change that other one.  Or, you can composite between multiple renders.

Compositing across multiple renders would be easier, I'm just not sure why its happening, the other shader is just a png with no transparency at all.

Sweet turned of the alpha on the other shader works perfectly. Its such a shame that's going to limit what I can do in future.


text:
How to maintain image transparency in the video editor
I have a render I've made of a model in blender and it has a transparent background, I've saved it as a PNG (which should keep the transparency) and imported it into the video editor. Once its imported it has a black background and the only way to change the transparency seems to be the opacity, but I don't want the whole image to be transparent. I've tried changing the film settings to allow for transparency but that hasn't made a noticeable difference.

How can I get the transparent parts of my image to be transparent again?
edit:

Would you mind showing the whole program window so that we can see at least a few settings?

Its currently at the default settings for the video editor when its selected from the blender launch window. The only things Ive changed is properties > render > film >transparency on.

btw its version 4.0.2

The Film > Transparent makes the scene background transparent for scene rendering, it has nothing to do with rendering image strips in the Video Sequence Editor. Please show the whole editor window, especially the Preview window and the Output Properties for the video file. Or upload your scene here: https://blend-exchange.com (best with the image sequence packed inside the file) and follow the instructions there to edit it into your question so we can examine the file ourselves.

@GordonBrinkmann updated post with image as requested

The Video Sequence Editor settings look okay. The first image shows the Render Result with transparency... have you checked the rendered files if they actually have transparency? Because the transparency shown in the Render Result is how it was rendered, not how it was saved. If you have saved the PNGs for example as Color > RGB instead of RGBA, the transparent background will be black because you saved the image without alpha transparency.

@GordonBrinkmann OMG, thank you, yep I saved it wrong.

By the way, if you are not going to overlay this sequence inside Blender on some background showing through the transparent parts, rendering it like this as a video will get you a black background as well, because the default encoding settings are saving a video file that does not support transparency (see the missing RGBA in the output properties). Only the Video Codec "QT rle / QT Animation" and one or two others support transparency.

Have you enabled the Use Alpha option under the Image or Movie strip properties in the Video Editor? This should preserve the transparency of your PNG image during the import process.

The previous commenter already helped me fix the issue, my png didn't have an alpha channel to read


text:
Mesh is invinsible after exporting model to Substance Painter
Earlier today I tried to export my model to Substance Painter, after doing that I realized that a part of my model is invisible in the program.

After searching the web for a bit I found out that negative scale can make mesh invisible, and after checking my scale I found it that it is indeed negative in that specific part of the model.

Now, the problem is that if I change the scale the whole mesh is getting messed up. Is it possible to change the scale without messing the object or fiddling with it too much afterwards?
Blend file:

Edit
Upon further inspection, I also noticed that from different angles some parts are visible from the back but not from the front, it looks like a normal issue but as you can see from the blend files all the faces are facing the right direction

Hello, have you tried applying the scale ? Object > Apply > Scale

Relevant - https://blender.stackexchange.com/q/7298/110840

You should also check Face Orientation view as part of inspecting a model.

@AllenSimpson I've checked the face Orientation and it is fine, I'll check the post you've sent and the Scale thingy in a moment

@Gorgious well it seems that Scale didn't change anything after exporting

I just checked your model and you do have face orientation problems, the red area should be blue. In edit mode and with all selected go to Mesh > Normal > Recalculate outside.

After that, everything is fine

I just found out about it myself and was about to post an answer about it, but you were quicker ;)
Your reward is my thanks ( and accepted answer of course )


text:
Deleting a face leaves weird ghost edges
After removing a face from a box 2 ghost edges were left behind. I can't select them nor delete them using x -> edges.

as you can see, when I select those 2 vertices the edge between them isn't being select like it doesn't exist. How do I remove it?
Thanks!
Blend file: Sorry for my amateur modeling skills, that's my first model ever and I'm not following a tutorial :3

Hi, and welcome to our stack exchange.
Do you have any modifiers on the object?  In edit mode, in some configurations you can see the modified object under the unmodified one that you're editing.  I also suggest posting your blend file to help someone answer your question faster.

Hello! I don't have any modifiers on the object. I'll post my blend file in a second @jwrush

Your model is fine, and impressive if your very first one.  Good luck and have fun with modeling!

What looks like one point is actually several, all on top of each other:

This is actually a pretty common problem that happens while modeling in Blender. You can fix it by selecting all of the points on the mesh (hitting "A") and then selecting Merge By Distance from the Clean Up Menu.

You'll then be able to select and delete the edge you want to get rid of:

Well it deleted 46 vertices 0_0
How come that those vertices appeared?

Really hard to know, could be any number of things that happend, but I often find in my own case that it's from copying parts of meshes in the wrong way or even just sloppy key strokes.  If you find them on the center of the mesh (not the case here) it's usually because of mirror modifier.

Extruding and then canceling movement with right click is a common cause.


text:
How to bend connection between 2 curves?
I want to draw lines on the surface of an object and then connect them. I am doing this by drawing curves. When I connect the curves the connection between them has sharp edges, which I don't want. I need something as the draw tubes in this video: https://www.youtube.com/watch?v=SgkzU8vhCj0. How do I create  rounded edges (indicated in red) as in following figure:

You may have your handles type set as vector. Try selecting the points you want (or the whole curve) then press V and select Aligned.

@ChristopherBennett this does not lead to the edges being rounded


text:
Normal map cannot be baked properly
I am trying to bake normal map but this does not work.
The half of map is broken.
Please help me.

How does the UV map look like?

I added UV map. Thank you.

hello, maybe share your file? https://pasteall.org/blend/

sorry I tried to share my file in different ways but it didn't work somehow.


text:
Combine objects and remove interior faces?
I want to start off by saying I am in no way a blender genius. I have about a year of diddle dawdling myself around and following a couple of tutorials. Today, me my ADHD self and I, decided to recreate my logo in 3D! Yay! And I got pretty far. I designed the shapes, lighting is a B, but I got a somewhat decent result for my purpose of staring at it when I am bored. But then... ADHD me wanted more. I needed more! I wanted frosted glass instead of black nothingness for the features! This is not a biggie as I have followed a couple of tutorials for this but then I cam across this problem.

Now I don't know about you, but whenever I see glass, it does not have funky planes visible! I made the general long line first and then the 'teeth' of the mouth, then I shift clicked them all and used
ctrl + J
to join them. The problem with this is the shapes didn't become one solid object, they became a bunch of intersecting 3D items that look terrible with 3D. This is in edit mode (yes I know my modelling skills are not up to par, I am a self taught teen leave me alone):

How can I combine the shapes in a way that deletes the interior faces and makes the intersections create vertices? Thank you all who can help or point out my stupidity.
EDIT:
While waiting, I started to mess around with object modifiers as I realized they work with joined objects. I used the remesh mod to generally fix the inside, but now the object is kind of squiggly. This  is a work around for now, but any real answers are appreciated.

Could try using booleans

Could you elaborate?

Sorry, I was thinking that if you were to separate all the parts of the mesh with P, then you could use the boolean modifiers union mode to better connect them. Or you could also use loop cuts to create support geometry and merge the intersections together.

The best way to get rid of those inside faces, is to manually delete them...
Go to wireframe, and when u start doing it, make sure you're not deleting faces u want to stay... But in case u delete something by accident, select the vertices of the hole/empty face, and click F to fill it with a new face :)
Now, for merging faces together, u need to merge the vertices. U can do this by selecting both vertices u wanna connect, then press on your keyboard Alt+M, then click "At Center"
If u don't understand much of what I'm talking about, then search up for some tutorials about merging faces/objects and topology in YouTube
Hope it helps ^^

Note that you can select all interor faces in a mesh by going Select > Select all by trait > Interior faces


text:
Blender sculpt symmetry is asymmetric! [issue]
Symmetry is not working in sculpt mode: when I point the brush to a random polygon, you can see one of the blue dots is outside the mesh, like the symmetry axis is offset. You can see the issue in the image below... thanks a lot for your help!

hello, symmetry will use the origin of the object as the center, is it correctly placed?

I center the pivot point but the same issue is occurring again (added an image on the initial post)

maybe share your file: https://pasteall.org/blend/

https://pasteall.org/blend/78386c998ab542adbf57f832ffbf1931

Select the local orientation to check the origin's orientation:

As you see it is tilted, i.e. not aligned with the global orientation, so the symmetry won't happen as you expect, you need to apply the rotation (CtrlA):

How come mine isn't? https://ibb.co/vQfLX3g

BTW ok now it works! Thanks a lot

you need to display the local orientation, in your image you display the global orientation


text:
Transform specific vertices of primitive mesh/extra object using geometry nodes?
I just started learning geometry nodes, and I have a question about manipulating specific vertices for meshes other than the original object that the geometry nodes modifier has been applied to.
Here's a node setup where I'm able to alter the X position of vertices on a plane object

From what I understand, this works because I created two vertex groups that become attributes that I can reference in the modifier.
However, am I still able to make specific-vertex adjustments to geometry that is not a part of the original object's mesh, such as a primitive or a separate object in the outliner?

Perhaps you're looking for "Named Attribute" node.

EDIT:
I managed to achieve this effect by using the index nodes.

However, I still there's still probably a better way to specify a group of vertices using attributes
EDIT #2:
The named attribute node can retrieve attributes from other objects. I think this is the best way to do it. Thanks Markus


text:
How to make liquid simulation splash
For too diddly-darn long I've been trying to create a specific scene in blender involving a large splash as a car enters the water. It's never resulted in a particularly satisfying splash and today I began anew with a fresh file and stripped back the scene to the root of the problem.
https://pasteall.org/blend/0e21c3293c184588aba5f9507cc4b5b6

I have a still source of water and an effector (invisible but very similar shape to the car) dipping into it as shown. However it seems only to push the water rather than making a large splash. It just doesn't look right. I haven't made any adjustments to the fluid simulation except for decreasing it's viscosity. Can someone explain why the water behaves so weirdly and what I can do to produce a more realistic splash?
Regards, Confused User

It would be easier if you could upload the blend file.

Looks like you have viscosity turned on …

there are also some values like Resolution, Particle Radius and Sampling that may play with the water thickness... As Mqbaka says, please share your file: https://pasteall.org/blend/

My Blender file is 29mb so pasteall and blend exchange don't allow me to upload the file. I don't know how to reply to specific comments so I hope you see this. Again, no settings on the water have been changed except viscosity 0 and I use a simple effector keyframed to dip into the water as shown. I am inclined to believe that a higher resolution division would help as mine is currently set to 32, but my computer is just a crappy lil laptop and I don't think it can run it.

I have since removed the fancy car model and uploaded the file

@Confused_User I saw your edit of my answer. You're welcome :-)

There are a few options to create big splashes.
1. in the Physic Properties settings of the Liquid Domain is an option called Fluid > [X] Liquid > [X] Fractional Obstacles. When it's enabled obstacles will create much more splashes.
2. you are dipping the car into the water ;-) There won't be big splashes. You need to throw the car into the water. Change the keyframes so the car will drop from about 20m height within the first 20 frames. It needs some speed. Rigid Body physics also works.
3. the higher the Fluid > Settings > Resolution Division value is the more liquid the fluid will be. But this also increases simulation baking time and the number of vertices. This value depends on the size of the liquid domain.
In the example, the dummy car is scaled down to 0.5 to make the splashes look bigger (just a test). If you have a car in real-world size, it might be better to leave the car alone and double the size of the liquid domain and the liquid source and adjust the Resolution Division value. Don't forget to apply the Scale to the objects with Ctrl+A in Object mode.
Increasing the FLIP Ratio might be another option (not tested). The default value is 0.970, and the max is 1.0. Not sure if it has a big impact.
Examples for different Resolution Division values

96 Resolution Division, several minutes baking, 170k vertices, lag in viewport (2 frames/sec playback speed in solid mode)

48 Resolution Division, a few minutes baking, 41k vertices

32 Resolution Division, quick baking, 17k vertices, low splash and it goes in opposite direction

animation with 40 Resolution Division


text:
Texture runs completely off the mesh and looks different to material preview
I downloaded a simple wood texture and am trying to apply it to this bowling lane. I got node wrangle to set up the nodes for me, and then did a UV wrap projected from top view. In material preview it looks completely fine, but for some reason rendered view makes it looks atrocious

I did admittedly do some meddling with the mesh earlier in the setup. I had the lane you see there split into two pieces then re-joined. I don't know if this would affect it though, and I had no idea the texture could run off the mesh or look different to material preview
https://www.cgbookcase.com/textures/parquet-flooring-07/
Any help is greatly appreciated

@moonboots That should read pack your images! File > External Data > Pack Resources. :^)

oops sorry yes, could you please pack your image and share your file: blend-exchange.com

@Confused_User A texture cannot show up in "empty space" without a mesh. It just looks like that in Rendered view because the outline of the selected object shows the object as it is without some modifier that becomes visible in render and produces this outstretched version of the object. There is a modifier on the "Lane" object, which one is it? You're not showing that in the screenshot.

If I see the material correctly, you have some displacement there. This for example is something that changes the geometry in rendered view but shows the outline of the unchanged geometry.

@GordonBrinkmann There was an array modifier on the lane but even when I remove it the texture runs off the mesh. It also has a rigid body simulation passive on it, but that shouldn't change anything

@moonboots oops, yep, sorry, uploaded the file now. I forgot to pack the image so I'll just provide a link to the textures

It doesn't look like you've shared the good file, there are just 2 planes that don't have any material

@moonboots It is there, but it's in a different scene sorry

You're using a Displacement node, it displaces the topology and can only be seen in Renedered preview, unplug it, or in the Material > Settings > Surface > Displacement, choose Bump Only, or if you want it to work properly, apply the scale and subdivide your object :


text:
missing some shadow in render result
I found out my render result and viewport rendering preview are different, my render result missing some shadow. I've checked and ensure the missing shadow is caused by viewport shading. Please help me QQ thank you
here is the picture with viewport preview and render result

Hello, maybe help with some screenshots, specifications (Eevee? Cycles?) even maybe share your file (or a part of it): https://pasteall.org/blend/

hi, I just upload it :D I forgot it

could ypu please share your file?

here is the file link, sorry I don't know how to upload a file in here
https://drive.google.com/file/d/1IqP2FLanIFoK19vrMkwtG5i7noqmgK9d/view?usp=sharing

no problem but your way of sharing the file works too ;)


text:
applying "clamp to" and "limit location" constrains to the same object don't work correctly
I'm trying to animate the lock mechanism. So I need each pin to follow the key relief. For this challenge, I made a curve path and give my pin "clamp to" constrain. It follows the path perfectly when I move the key, but it moves not only on the Z-axis. So I add "limit location" constrain to limit X and Y-axis movement. After that pin stays at Z-axis but does not follow the curve exactly. the same story if I copy X and Y coordinate from a static object by "copy location" constrain. I made simplify scene for a better explanation. See gif for more detail.
Thanks for any advice.

Thank you all for your advice, they are extremely helpful. "Shrinkwrap" constrain on project mode from Nathan's suggestion works pretty fine if the key angle is not really extreme.
Chris's solution is kind of working, but the key movement is not linear, so it was tricky to make movement for the rest of the pin, and baking animation as an action doesn't help as well.
I get a better understanding of constraints thanks to Markus von Broady, now everything is clear. GIF below shows the difference between "Shrinkwrap" (on the right) and baked animation ((on the left))

A constraint simply clamps the location to a valid value, so the cone is still being moved as on the first GIF but then is moved horizontally to where it's constrained.

Use a shrinkwrap constraint on project mode to do what you want instead.  If you need to make a mesh out of the "key" silhouette to do that, you can always make it a non-rendering mesh.

Maybe your shrinkwrap problem is caused just by the curve going below the original cone position? That is, move the cone lower.

Fake it 'til you make it ;)
So here is my solution proposal:

just use the object constraint follow path and let the key follow it (Blender does this work for you) - this you see on the left side

you can hide all objects on the left side, this is just where the data comes from

copy your pin and give it an object constraint copy z location to the animated pin

copy your path and give it an object constraint copy x inverted location

move the path to the right location

enjoy the result and have fun!

There is a hacky method here to achieve linear horizontal motion: Have the hidden curve x driven by an expression that uses hidden pin's x divided by curve's width, and current frame, to calculate how much that pin is behind/ahead. Due to circular reference in dependency (the pin's location relies on the curve, the curve's location relies on pin), the curve's location will update 1 frame later, avoiding feedback loop.

Your shrinkwrap constraint fails because the original position of the cone is already too far in regards to the target - just move it in the direction opposite to the projection direction:


text:
how to fix light leak from objects?

I'm not trolling!I'm really a beginner, the project im current working got a light problem,the light just leak from the glass hood in Eevee,but in another angle,which you can see it from chart 2,the ship hull is still intact,how do i make it completely clamp to each other?(the method i used is create a glass hood separately,then boolean it from the hull,but after i did that the hull is leaking light and the other side still intact)
EDIT:i found the problem is coming from the BG, the BG is a single frame pic, texture coordinated with window with emission, could be emission caused this problem? or the coordinate cant calculate correctly image in view?

maybe try to enable the Shadows > Contact Shadows of your light?

thx, it didn't work but after using your method I found the source of the problem, would you mind checking out my edited answer?

I didn't solve the problem, but I switch to the cycles. the problem source is the glass shader, I can't really fix the problem, but I'm pretty sure because of the glass shader setting.


text:
Grease pencil / 2D drawing in cycles?
I made an animation that is supposed to be rendered in cycles.
Now i'll like to add some 2D animation, impact smoke and such.
But i can see grease pencil doesn't render in Cycles.
Is there any work around this?
I seen you can turn it into a curve, and make it thicker.
But then i have no fill color, and it's a very slow workflow.
I could also make the animation in procreate, but i'm not sure if i can get it into Blender with a transparent background.
But it would just be much easier if i could draw an animation directly in blender and render it in Cycles.
I also thought about adding the 2D animation after, but some of the drawings is behind the 3D objects. So it would really be a pain to draw around or mask path of the objects.
EDIT:
It seems to be the Denoiser that is the problem. So either i'll have to do without it, or try to find some kind of workaround.
So any suggestions would be appreciated.
Link to my Denoise setup
https://i.sstatic.net/9YByN.jpg
I'm kinda inspired by the "Just a dash" intro.

This is a mesh + a Grease pencil object, rendered in Cycles.

Oh you are completely right, thank you, my bad for not checking in default. I figured out it's because i use Denoise, so either i'll have to do it without Denoise, or there is a workaround, any suggestions? https://imgur.com/a/eNSd10i


text:
how do I cut an image into a cube?
 how do engrave this image of a shogi game board onto the face of the cube, for context this is for a model I'm planning on 3d printing (just incase that changes anything)

Hi and welcome. Please provide at least a sketch of what you'd like to do, unclear what you mean by "cut an image into a cube", billions of options IMHO. Please use the [edit] link at the
bottom of your question (https://i.sstatic.net/lXFuK.png) and add
more information about your actual goal.

You could do it with some extrusions

You can add the displace modifier to your cube, and click the New button.
Then click on this button:

This will take you to the Textures Tab.
There, click Open and then select your image.
Now, go to the Edit Mode and subdivide your cube many times.
Then, select all the vertices of the face of the cube where you want the image to be, something like this:

Now, go to the Object Data Properties tab and click the + option in Vertex Groups:

Now, click on the Assign button.
Go back to the Modifiers tab and then click on the box next to the Vertex Group and select Group.
After going back to the Object Mode, the image will appear on the face of the cube.
Note that you can change the height of the image by changing the value of Strength in the modifier properties.
My example:
Image:

Result:

thx for all the help mate i had some issues with getting the right amount of sub divides that would let me get all the cubes and numbers looking good but not have blender crash>.< also my cube now has rounded corners so that's a pretty nice edition lol. Have a good one

You are welcome! :)


text:
Lost texture on a linked object far from the origin file
I've modeled a file of a little city with many object linked into it. Some linked model lose its texture when far from the world origin (if I move the object near the origin the texture reappears)
i've tried to duplicate/relink o re-insert the object but the problem still remain
is there some settings that I have to modify to solve this little problem? why could it happens?

thank you very much for the help!

How far are we talking ?

10 km more or less

How is the material setup in the base file ?

the material in the base file is quite simple, I don't know how to upload here some imagese but i uploaded them in this link. The strange thing is that, the same mesh, with the same materials in different files has the same behaviour in the "global file". in the we transfer link you can find the material setting and a tiny screen of the problem with the black rectangle - https://we.tl/t-jCQoeRBXky                                  thank you for the interest!


text:
My model used to work so fine, but now only its bones move, not the mesh itself with it!
Here's a image to show u what actually my problem is:

Didn't change any settings, except the textures.
I got the same model in another blend file that works so pretty fine but this one not! i really really need this to work!
Do ya know any way on how to fix it folks? :(

Hello, we can't see any image

hhh.. damn my internet connection, it's like i'm in a desert. I'm gonna fix that now

it's pretty incomprehensible, maybe pack the image and share your file

Dude i'm telling what the problem is, actually i'd recorded a clip of that to show everything i mean, but i couldn't share or upload it somewhere, if ya want, i might be able send it to ur Email. But the whole case: is that when i switch to the posr mode, and try to move a bone assigned to my model, it moves but the mesh of the model doesn't.

Don't really know why but pretty much restarting the whole system made it work :/
it's done.


text:
Why is there this ringed artifact in the render?
This is in Cycles, sample count doesn't seem to affect anything.
I have 2 volume cubes, the rings only appear when both are enabled.

It only appears in the render, not the viewport. There is nothing in the compositor.

One of the volume cubes has variable density with a gradient texture and curves.

I tried all combinations of volume sampling and interpolation - no differences. I also experimented with the step rate and still nothing.
Blend File

Please provide blend file

The blend file is included now


text:
Modify a 3D Model of a Turnstile
I'm completely new to Blender. I have a DAE file which has 4 access turnstiles and I want to delete one of them to create a 3 access turnstile. I'm using this in Sweet Home 3D.
I have imported the DAE file into Blender and have deleted one of the turnstiles. I have selected all of the objects and selected export as Collada. When I then import the file back into Sweet Home 3D it only has one object. I'm obviously doing this process wrong.

The easiest solution I would suspect is that in the export dialogue box you have Selection Only enabled. If you can't see that on the right side of the box, hit N to bring up the side bar menu.

The  'Selection Only' enabled is not ticked?


text:
Geometry Nodes: Place different objects dependend on location with vertex color
I edited my question to hopefully make it more clear and easy to answer:
What is my goal? I want something similar to this in blender: https://www.youtube.com/watch?v=RfyXNhOnQQg&t=3m2s
My starting point is a plane where I delete faces based on vertex color to "paint" geometry. So far so good.
Then I select the faces in the corner and edge of the plane, so give them a different material.

But now here is my problem: I want every face at edge and corner have a different material, based at which direction is outside. For example for the orange corner, the outside is +Y/-X. But how do I get this attribute and select with it?

If it's not possible with this method, I'm open for other ideas. My goal is just to automatically place a fitting texture to corners and edges to save a lot of time in contrast by placing every cube/texture by hand.
Thanks in advance for every help!

Are your corner tiles rotations of one another, or separate entities?

Best case separate entities, but rotation could work too.

Possibly related: how can I make instances responsible to each-other

@MarkusvonBroady thanks, will look into it!

Here is my attempt:

Inside node group:

The idea is to look at 4 edges of faces and set a color based on there this edge is located around face center.

thanks a lot, looks convenient. Unfortunately I couldn't get it to work if I put my vertex paint method in front to delete faces depending on where I paint. Seems that the indices get messed up.

you should plug mesh data into node groups after removing vertices

Ah, I had something else wrong, works now! I think that answers my initial question. But maybe I can get it a bit further: Is it also possible to select the inner corner faces (black marked)? https://imgur.com/a/qYq2exN

@Trick it's feasible, but more complicated. It should get vertices of 4 corners and check how many face corners are connected to each vertex. If it is 4,4,4,3 it should be that face.

I understand the logic behind that and tried it several ways, but I have no idea how to archieve that so that I can isolate the wanted faces. The whole attribute and index thing is not very intuitive for me.

you can use separate geometry node to separate faces by compare node result. You can ask another question if you faced problems with that


text:
Light bouncing (Unity)
I am trying to make a cube/cuboid emit light. Now I am succesful in making it luminous (lighting up without the help of other lights), but it is not lighting up other things.

I have noticed switching the render engine to Cycles instead of Eevee fixes the problem, but the other problem is I am not trying to render it, but import it to Unity, which is not for rendering.
Also, rendering it Unity provides no color:

What should I do to make it light other things?
btw yes, i am making mettaton from undertale

First of all you are correct that eevee and cycles will give you different results. Cycles with 0 settings from you will do most of the work for you and it will look good but Eevee is realtime render and as such it has lower performance with shadows and light... such as this is normal and if you want to see light glowing you can only check "BLOOM" in render settings... If you want to see it in Unity, did you already tried to export it to unity and see if it works or not? because this is simply Eevee real time render issue

@MikoCG I have tried to import it into Unity and it is not colouring any of the emmiting parts.


text:
Unable to bake normalmap without artifacts
I've got 2 human male meshes from an asset-webside. Those are low-Poly and high-poly versions of a human.
I tried to bake the normals for the low poly version multiple times with different approaches but got some weird resulst every time (Image as reference).

So far i tried:

Different normal Map Sizes
Many different ray distances
Using a cage (minor improvement)
Unwrapping the UV's in different shapes
Using different materials
Changing the sizes of the meshes or normals (ALT+S)
Subdividing the low-poly version for more polies
Shrinkwrap the to models to fit each other

At this point i don't have anymore ideas what setting i could change to make this work and couldn't find anymore tips on similar topics.
Maybe i'm just missing some small detail or doing some rookie mistake.
I'll include two blend files. One is the file at the very beginning and the second one is my result at the end.

https://easyupload.io/m/h0jl79

If anybody got anymore ideas i would really appreciate your help!
UPDATE : Images

This is the base white material i'm using the whole time.

The same Error with a different material.

Hello, your links say that the file has been deleted, maybe use https://pasteall.org/blend/ But are you sure your original object normals are correctly oriented?

Hi, thanks for the advise for the download. I tried that with no improvements unfortunately.

The scale is very small (0.01), first apply for both the 2 objects, then give a bit of Extrusion (I've tried 0.03), no need for Maximum Ray Distance. Also, use an 32-Bit Float image:

First of thanks for the tip! It worked for me the first time i tried it. Unfortunately i didn't save the result image. I've been trying to recreate that image with the same steps but without any sucess. The normal map itself looks quite good to be hones but in the Viewport it's only working parcialy. Some areas look great but others are just painted even brighter then before?

could you please share your current file?

Of course : https://easyupload.io/gaxl34.

choose an Extrusion value of about 0.025 which seems like the best you can get, then you'll probably need to give it some correction in Paint mode, either in the 3D view or in the Image Editor

(which means use the eyedropper to get the blue color and paint over the bad colors)

Or another solution is to find the Extrusion value that will work for the bad parts, then mix 2 normal maps

Thank you for your solutions! I tried painting over the areas but it didn't fix the problem with the white spots. Like half of the meshes is this white tone and even after painting over those parts it stays the same. But the "deformation" of the meshe by the normal map changes as desired.

mmh I didn't see any white spot so I'm not sure what's happening in your case

I posted two picutres in the originals post from my viewport to clarify the issue.

ooh ok, I thought you were talking about the normal map colors. So you need to enable the 32-Bit Float option when you create your image, then select it in the Image Texture and bake again

The 32-Bit fixed it! Thank you so much :)


text:
Property Menu Dissapeared
While I was making my object, I accidently closed the property menu on the bottom right of the screen. I want to know how to get it back. Im also a beginner at blender and the "How can I reset my menu?" question won't help.

Im not really sure, it seems as it is from an older version of blender.

It's still the same and worth reading.

If you didn't know, I'm a beginner at Blender and maybe you should simplify it, instead of just thinking I know a lot.

If you don't know, we all try to help in our spare time. It's not my job to 'simplify' anything for you. Recommend edit your question and explain what exactly "won't work" and what you have tried so far.

Hover over the bottom right hand corner of your asset list (above your version number) and your cursor will turn to a cross

Once it has changed to this cross, click and drag upwards to open a new panel. You will probably get another panel with your assets listed. Click on the drop down tab highlighted below:

Now select properties

This will open a new properties panel in the same place as before


text:
Procedural material texture scaling
Hello everyone people!
I have the following question.
I got a .blend with a ready-made material that I found on Blendswap. This material allows procedural concrete to be applied on random surfaces (this is important because in my current project UV Maps is not an option at all). The material looks very good, but I would like to enlarge the spots of this... uhh... "dirt" let's say (circled red on the picture).
But whatever I try to do with the scaling (circled blue in the Shader editor and green on Right bar), there is no way to get "dirt" grow larger than on a pic. There's some kind of limit, which seems to be about 0.001 or less, that does not allow dirty areas to be larger. If you pass through it, the "dirt" just disappears.
Do you have any idea how to make this "dirt" take up, for example, 90% of the surface or more?
Attaching a file with the material, would be really thankful to hear any ideas.
Blend file on the link: https://drive.google.com/file/d/1a24zb4Bt_qgs2XMxQbHy9p38c-lwPJPY/view?usp=sharing

UPD: Marty Fouts' suggestion below works fine, but still not able to pass throug 35% rough and 65% regular surface, the maximum amount of rough area I managed to max out is on the screen. So any ideas to get at lest 50/50?

That "dirt" is the rough area of the concrete generated by this part of the node group:

The way they interact, you have to adjust the color ramp labeled Huge Wear Mask as well as the Detail and Dimension of both textures.

Yeah, works fine, thanks! But this still isn't the result I'd like to see. There's also some kind of limit not letting tough areas to take up the whole surface. I've tried to max it out and the best proportion I got is probably 35% rough 65% regular surface. Any ideas how to get 50/50 at lest? I'll post a screenshot with my next answer, don't see if I'm able to attach images to comments.

Edited the OP instead* as moderator advises me.


text:
I get white squares in my final render (cycles)
Weird whiter parts are appearing on my final render

My render settings are
https://i.sstatic.net/x5nqQ.jpg

Hello :). This can sometimes happen with tile denoising enabled. Solution is to Denoise in Compositor. Please add an image of your render settings, otherwise it's just guessing.

https://imgur.com/a/abcHsd4

@VaffelLord don't post additional information in the comments, instead [edit] your original  question and add it there

Hey :). It might be a bug related to combined GPU+CPU rendering. It was mentioned a few times before - Why are these tiles appearing in my final rendered image?

Beat me to it ;-) Suspected GPU issue. Try rendering with just CPU and see if that helps.

Hey :), when i turned my Ryzen 2600x off in optix the problem dissapeared thanks Jachym Michal


text:
How do I fix the edges that runs around my cube from becoming really long when scaling on an axis?
I'm really new to blender, and I thought I'd make a cube for my game that has glow in the middle and edges running around it. I extruded faces inward to make the edges, but when I scale the cube in any axis the edges of the cube that face that axis becomes really long and it doesn't look good at all. Any way I can fix this? I looked around and couldn't find any solution, therefor I'm asking here. Thank you in advance!

Here's the file

hello, how did you make your edges? maybe pack the images (if there are) and share your file? https://pasteall.org/blend/

@moonboots I made the edges by extruding the faces of the cube inwards. I attached the file to the original question (I think) Have no idea how to attatch files really to this site really

If you want to stretch the cube without deforming the edges, you need to modify the mesh itself in Edit mode, because if you stretch it in Object mode will also change the edges width, so switch to Edit mode, press AltZ to have transparency, select the vertices of one side, and move them along the axis you want:

oooh. Thank you very much! :)


text:
Connecting node trees using blender api
I am terribly confused why this is not working. I have followed similar examples and failed (i.e. Blender scripting connect nodes)
bpy.context.active_object.active_material.node_tree.links.new(bpy.data.materials["Material.001"].node_tree.nodes["Principled BSDF"].inputs[0], bpy.data.materials["Material.001"].node_tree.nodes["ShaderNodeTexCoord"].outputs[0])
If my code is too difficult to decipher, here's a summary: I am just trying to link the Texture Coordinate node output to the Base Color input of the Principled BSDF.
I wrote out the whole line above without using any variables in the aid of clarity/searchability.
Thank you all!

Your last part includes .from_node. which is not correct offhand.

Thanks for this, I have tried without as well. Same result. I will edit the question above for clarity.

did you select an object when running your script?

what is the error of python?

Re clarity and search ability, not convinced it has have achieved either.

make sure your name is set to right value, not just the label.
"

If the active objects active material is not material "Material.001" then code in question won't work... could be another guess-timate.

Nobody with little python experience would code it in that way - so I totally agree with you


text:
Blend shapes, but for textures/decals...?
I'm trying to understand how to rig a very simple figure/head with blend shapes to use through a animation framework in unity. Now I made the head so low poly that the actual facial features would mostly have to be textures sliding around. So I think I should understand and learn to use decals, but I suspect those might not be covered by blend shapes.
Can I use blend shapes for UV maps and/or decals or do I need to make a bunch of loop cuts in my low poly model as a workaround so I can use them?

Edit: I understand the term blend shapes as a collection of distortion maps which can be combined, each weighted by a factor, to quickly produce complex distortions in a mesh. The term distortion map was made up by me to describe a mapping of vectors for each vertex in a mesh, describing the offset from its original position. This appears to be mostly used for facial and similar animations, where one tries to simulate organic shapes with many points which all move differently based on the surrounding points.

Hello, what do you mean by blend shapes? Maybe show some screenshots? Do you want to use image textures? In that case check this answer: https://blender.stackexchange.com/questions/181389/how-can-i-animate-a-2d-face-rig-on-any-3d-object

I tried to explain my understanding of them.
I found something similar to your link, but it does not allow me smooth transition between states or partial positions.


text:
One mesh multiple UV Baking
So i've managed to join the mesh into a single object before rigging. Before doing so i follow this tutorial so that i the textures can be retained even so when it has distinct uv maps {https://youtu.be/Ohg98v0H534?si=NStUAX6htyYhFL7U} i followed this. On this tuts the tutor also showed the overlapping uv island if we edit select all the faces.
Now i want to follow this tutorial https://www.youtube.com/watch?v=WNAQgQGRmgQ&t=9s&ab_channel=PixelicaCG but i can't seem to resolve how to do that with one mesh that has multiple uvmaps with the same name.
When i tried to pack uv island manually just like the video said on the bake uv maps, the texture moved on my model.
I don't really know the intricacies behind uvmap tab in blender, how do i bake all of the texture into a single for say diffuse map on this particular issue.
https://drive.google.com/drive/folders/1n0rDFoNlvtjlWzuslymM4MG37alDH1Wt?usp=drive_link here's the attachmen
Added image attachments

notice that the uvmap name is joined and there are corresponding texture for parts that can be selected by press l hover

here we can see the uv map also have the same naming with its texture and uv islands
PROBLEM:

just like the tuts i arrange the uv island by selecting bake uv map and the arranging but what it did also change how the texture is presented on my model

Thank you for your help!

You have better chances of getting a answers if all of the information is visible in this page, instead of asking users to visit links just to understand your question. Please use the [edit] link at the bottom of your question (https://i.sstatic.net/vHwEx.png) and use the tools on the site to upload images directly. See: How to upload an image to a post?.

You need to add a UVMap node to you shader which lets you select which map to use. Add that one on your "Bake To" object with the Joined uv set selected, plug that into the texture you're baking to.


text:
How to model a satellite MLI blanket? (as a mesh)
I am trying to model a satellite MLI blanket, like these ones:

I have to say that I am not interested at all about the colour, or the glossiness, only the geometry. I am really trying to obtain a correct mesh.
EDIT: Thanks to @Duarte Farrajota Ramos, here is my new attempt. First I tried to work on the same mesh:

Then, inside the Cloth modifier, I have chosen the Silk preset, have put Pressure to 0.1, added my Group to the Pin Group inside the Shape submenu, where I have set the Shrinking Factor to -0.12. Still, there is an absolutely perfect symmetry on the object, which I am trying to avoid. I don't know how to avoid that, or what I am missing, as @Duarte Farrajota Ramos in his answer succeeded to obtain something more "random":

NB: For information, here is my Modifier menu:

I don’t think you want pressure, I think you want the pins to pull in a bit so the fabric has just a tiny bit of slack that adds wrinkles.

Have a look at sculpting with cloth simlation: https://www.youtube.com/watch?v=Y5J5os8P4jg

@TheLabCat How can I do that? I tried but didn't get a correct result. I cannot use sculpting, because I will need to automate the method using Python's Blender API after.

Make your mesh high poly enough, that there is enough detail for the cloth simulation to operate on, but low enough that you can still model your shapes confortably. Subdivide after the fact with a Subdiv modifier if necessary.
Your topology should also be more or less uniform. Avoid faces with large size differences, prefer quad dominant topology, and make faces approximately square shape in aspect ratio.

Select all edges, borders and zones where the MLI blanket is attached or fitting tightly around the hard surface underneath it, and add it to a new vertex group.

Add a cloth simulation to the object. Turn on Pressure under Physical Properties, and add a value anywhere around 10 to 20, depending on your mesh density. Under Shape add the previously created vertex group to the Pin Group property.
The key factor is now to use a negative Shrink Factor with a low value of around $-0.01$ to $-0.05$. You may  also want to lower or entirely disable Gravity under Field Weights.

These values will vary depending on the size, density of your mesh topology and level of subdivision, adjust to you specific case.

To get bigger coarser wrinkles, use a lower detail mesh with sparser subdivision.

This is really excellent, thank you. My only problem is that my rendering is symmetrical (I've put a picture on my first post), but yours looks more random. Do you have an idea why?

Probably cause by wrong modifier order, no? You might have a Mirror modifier after the simulation, rather than before.

This is something else.. I haven't used a Mirror modifier.


text:
Create topography from vertices
I'm very new to Blender and recently I have been trying to model topography I have gathered from USGS lidar surveys. From the data that I have gathered, I have created a series of vertices that represent the topography. The vertices look great in blender but as of right now I do not know how to connect the vertices together to make faces.
This is the code I am using to get each of the coordinates (vertices):
csvfile = open("path/topopoints.csv")

inFile = csv.reader(csvfile, delimiter=',')

vertices = [(float(r[0]), float(r[1]), float(r[2])) for r in inFile]

name = "grid"
mesh = bpy.data.meshes.new( name ) #Create the mesh (inner data)
obj = bpy.data.objects.new( name, mesh ) #Create an object
faces = []
polygons = []
obj.data.from_pydata( vertices, faces, polygons )

bpy.context.collection.objects.link( obj ) #Link the object to the scene

This works well and puts the vertices in the correct position, but I am trying to figure out how to generate the faces (or polygons) required to connect all the vertices of my mesh (To make it look like topography).
Any help would be greatly appreciated and if you have any questions or comments I will be sure to respond quickly.
EDIT:
Here is how my scene currently looks.

Above image shows starting vertices at bottom right.

What order are they in? Look at the vertex indices, If it's a grid see https://blender.stackexchange.com/questions/230534/fastest-way-to-skin-a-grid  could look at reading with https://blender.stackexchange.com/questions/190977/how-to-load-npy-file-into-blender

They are ordered by ascending x value

All of them? In grid example shown ordered by y then x (y going bottom to top, x going left to right) do you get a grid of verts?

Related https://blender.stackexchange.com/questions/223764/numpy-lidar-point-cloud-to-mesh-how-to-separate-polygons

For example, the first few rows of my list of vertices looks like this: [(0,5,4),(1,5,8),(3,6,2),(5,2,1)]

Also, I looked through the resources you linked and I'm not sure that they can be used to solve my specific question. Link 1 would be useful if my data were in grid form but I don't believe it is.

THat really does not help.  Can turn on show vertex index in viewport overlays. With your mesh in edit mode select a region of verts (around index zero would be good) and [edit] into question as a  screen shot image.

Ok. I updated. You can see on the far right we have indices 0 ,1, and 2 amongst other indices displayed.

Consider top ortho view.

I added a new image that hopefully displays this

Which USGS program are you talking about.  this one?  If you're gathering 3DEP data, you'll need to use USGS (or other) tools to massage it into DEM format.  Otherwise, you've probably got a point cloud and need a way to analyse it.

I'm using Open Topography and I initially got my results as a .las file, however I can also get my results into .dem format if you think we might be able to do more with that.

The BlenderGIS addon among others does a good job of using DEM as height maps to make topography.  Unless you want the topographic lines, then you need some kind of marching cubes approach.


text:
I have made this counter in geo nodes that counts up 1 on each frame. How can I make it count back down to 1 once it gets to 10?
I'm trying to figure out how to make the number count to ten then go back down to 1.

If you are using Simulation zone just to get this result you can achieve it without using it. The node set up is similar just uses the Scene Time node to get the frame number:

Dooooh! :) I got locked into the question ...

Still a very valid answer :)

here I am using #frame

This should do it:

it's set up to give you  1  on frame 1, and cycle back and forth between 1 and 10 thereafter.

This is more idiomatic than R. Betts' answer:

With an added benefit that it won't start malfunctioning after 16777216 frames (which I imagine you will never reach for multiple reasons, two of which are that it would take too much time to render that many frames, and that if you tried, Blender would probably crash before you reached that frame…)
However if your question isn't some simplified example of an actual problem, the real solution is to replace the entire simulation zone in Robin's answer with Scene Time: Frame node.
Also for a very similar reason to the 16777216 frames thing mentioned above, my setup can stop reversing if the counter exceeds that value (if the max value is higher).

Mind blown, but the range is from 1 to 10 and back to 1. No zeroes :)

Hehe....  I must visit the country where this is an idiom....... are Blender floats 32 bit?

Idiomatic, because it literally works (is implemented) as OP described it (except with the off-by-one error mentioned by Rumen, I'll leave correcting it as an exercise to the reader). @RobinBetts yes, not everywhere, but almost everywhere, including geonodes, it's "single precision" float32.

@MNB. Ahh. OK ..that's something I didn't appreciate. Thanks!


text:
Why is my texture stretched?

Why is my texture stretched on the front leg? I tried applying scale but no change. I wish I could supply more info but I'm not sure what would help since I'm very new at this.
(update) managed to find doubled vertices along one of the seams which cleared up some stretching. tried to minimise the amount of cuts but still have issues. adding the file, really appreciate if you have a look.

well answer is quite simple, your cuts are not 100% right, I cant see your whole mesh, your file would help, or at least your UV map, but what happened that bend are of that place wasn't able to unfold as squares and it stretched itself... do you have bevel on the edges?

ok. nope no bevel nut i have a sub surf mod.

top face of that leg is part of the leg or cut with seam?

It would help to see at least a screen shot of your UV editor window with everything in the chair selected in the edit window.  Better would be if you could include your blend file: (How to add a blend file)

managed to find doubled vertices along one of the seams which cleared up some stretching. tried to minimise the amount of cuts but still have issues. adding the file, really appreciate if you have a look.

Some distortions are caused by the Subdivision modifier. We can see this if we disable the Display modifier in edit mode option.

In the Subdivision Modifier menu it helps if you change the UV Smooth type from Keep Boundaries to Keep Corners.

You may also find that now if you UV > Unwrap the "leg" object again you will get better results if you change the Unwrap Method from Angle to Conformal.

Awesome! thanks!! still got some stretching on the top of the leg close to back. But i think i can fix that with an extra edge loop

I have edited my answer to suggest that you also try now re-unwrapping the leg and this time change the unwrap method to Conformal.


text:
Positive "Instance scale" value returned for instanced objects with actually negative scale applied
I noticed something weird that nobody seems to have reported yet (but I am still using Blender 3.3.12, checked that the result was identical with 3.4.1 but can’t run newer versions on my current config): it looks like (at least these version of) Blender can’t return reliable results when you want to check the scale of an instance after you applied to it a negative scale in order to mirror it. The 3 attached screenshots show that

if I apply a scale [-1, 1, 1] without any rotation [0°, 0°, 0°], the spreadsheet
returns a scale [1, 1, 1] and a rotation [0, -0, π],
if I revert the scale to default [1, 1, 1] and apply a rotation [0°, 0°, -180°], the spreadsheet returns exactly the same scale and rotation values than with the previous setting whereas we can check in the 3D Viewport that the transformation is obviously not equivalent to the previous one.

If I add two nodes Instance Scale and Instance Rotation linked to two respective Store Named Attribute, they will also return the same wrong values than the spreadsheet.

I reproduce your disturbing results with Blender 3.6.5, starting from a fresh file also (scaling along X by -1 shows as rotation of 180° around Z axis in Spreadsheet).

Also a full "point symmetry", that is negative scale on all 3 axes [-1, -1, -1] shows as a simple rotation of 180° around Y axis

This issue has already been reported before. See:

Geometry-node object-info rotation&scale outputs values are False if scale is negative

Geometry nodes. Objects with negative scale have positive scale as instances

As you see, task is marked by solved, but 2 weeks ago. Fix is not in  official versions yet.
You can see fix in alpha version of 4.1 you can grab it from daily builds to check:

Unfortunately, it is not implemented for 3.3.15

was simply wondering if the current alpha version of 4.1 could
possibly be not totally fixed yet and returning a wrong mix between
two possible ways in terms of Rotation + Scale to describe a same
transformation matrix.

I made some tests, and it looks to me that it is fixed. The reason why it looks weird is that all transforms are applied to a transform matrix, and in spreadsheet you will see a decomposed version from this matrix. In this case rotation 180 on Y and scale (-1,1,-1) will result in the same transform matrix, that's decomposed in the same way:

Which was the transformation used while capturing your screenshot? If it was the point symmetry that I mentioned above, the scale [-1, -1, -1] is right but there should not be any rotation (I recently discovered using the "Matrix World" add-on, that the point symmetry can be obtained either by a negative scale on all 3 axes  [-1, -1, -1] without any rotation, or by a negative scale only on Z axis [1, 1, -1] combined with a half turn around Z axis [0, 0, π], both possibilities lead to the same transformation matrix but your screenshot looks like a wrong mix of them).

Of course thanks anyway, this information answers to my question even if I can’t run the 4.1 alpha version since my system don’t have the required GLIBC_2.28 ; I was simply wondering if the current alpha version of 4.1 could possibly be not totally fixed yet and returning a wrong mix between two possible ways in terms of Rotation + Scale to describe a same transformation matrix.


text:
Trim curve based on radius of control points using geometry nodes
I am trying to trim straight curves (actually converted from mesh edges) so that each endpoint is trimmed by half the value of its radius — so that if I succeeded, the new trimmed endpoints would be at the limits of cubes placed at the old untrimmed endpoints, each cube having the size of the radius of one of the old endpoints (somewhat like if the cubes were used to cut the curve using a boolean modifier). Unfortunately I haven’t found yet how to achieve that, the example file shows one of my various attempts.

On this screenshot the left cube size is 1, the right cube size 0.5, the curve left control point has a radius of 1, the right control point has a radius of 0.5. So I would expect the curve left end to be trimmed by 0.5 and the right end by 0.25.

That is a simplification to isolate my issue to submit here, but actually in various abstract geometric artworks I am currently designing https://skfb.ly/oMEUU lots of cube and curves are generated from the points and edges of a mesh, by a far more complicated geometry nodes setting with a variable radius field in order to create tubes of square section with cubes at intersections and turns.

If you just trim the curve to meet the end of the cube exactly, the meeting faces will not be the same size... is that OK?

I know, this is another issue that I also wanted to solve but I wanted to simplify my question before submitting it. I expected that if someone found the solution to store the initial values of the end points radiuses and use them for trimming, maybe I could also use them for a "Set Radius" node inserted after the "Trim Curve" node.

If you wanted a match anyway, it might be simpler to construct the cubes from the trimmed ends by duplication and extrusion?

In this particular case, I would not use the Trim Curve node if I were you, for two reasons:

When trimming, the values for the radii are interpolated, so you end up with incorrect values for Curve to Mesh.
You cannot create sections with it, you can only move the end points.

Therefore, I would suggest the following solution:

First split the edges so that you get individual segments. Before that, you capture the index of the points so that you can restore the radii after splitting.
Then simply move the respective end points along the tangents (or in the opposite direction) by the required value. In this way, you should be able to achieve the desired result even with continuous lines.
(Blender 4.0+)

Thank you very much! I had guessed that my problem had something to do with Blender interpolating, along the curve between control points, not only the value of the radius but the values of named attributes that I tried to use in other attempts and you are absolutely right that the use of "Trim Curve" had to be dropped. My config is quite outdated and I still use Blender LTS 3.3.12 but I could apply your technique to my simplified example > https://i.sstatic.net/bhCEi.png

Beyond the "Offset endpoints" section, the rest of your solution, splitting edges and instancing cubes, is almost what I already did in my more complex design but didn’t include in my example. If you are curious to see the solution in use, here it is > https://blend-exchange.com/b/2exsDjSG/

@robinfredericf Very nice patterns, I love it, well done!

Replacing the Grid + Mesh to Curve with a Quadrilateral is also very useful, not only it saves one node but also it generates tubes with already correctly oriented normals — with my initial setting I had to add a Flip Faces after my Curve to Mesh.


text:
Wrong bounding box dimensions for a Mesh Line node since Blender 4.0
Wondering why some 3d abstract patterns I did some months ago https://skfb.ly/oQuX7 (on my previous old computer where I used to stick to Blender 3.3) appear different in Blender 4.2, I managed to isolate the problem and it turns out that since version 4.0, Blender gives wrong bounding box dimensions to a mesh line generated by geometry nodes https://docs.blender.org/manual/en/latest/modeling/geometry_nodes/mesh/primitives/mesh_line.html (as long as the Geometry Nodes modifier is not applied)
Correct bounding box in Blender 3.3.21:

Wrong bounding box in Blender 4.2.2:

Both the bounding box optionally displayed in the 3D Viewport https://docs.blender.org/manual/en/latest/scene_layout/object/properties/display.html#bpy-types-object-display-bounds-type, and the rectangular cuboid generated if we add a "Bounding Box" node, appear in Blender 4+ larger that they should be: actually they show the dimensions that would be correct if the Mesh Line node "Count" option was set to one unit higher (in my example file it would be 5 vertices instead of 4)
I wonder if there is some justification to that or if it is simply a bug that should be solved in the future. For the time being a possible workaround is to add a "Split Edge" and "Merge by Distance" nodes after the "Mesh Line" node.

It does look like a bug. Instead of spliting the edges and merging the points, you can place a set position node with no values. It should be less slow.

Thanks for this tip and also for having quickly reported the bug yourself https://projects.blender.org/blender/blender/issues/129388