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Blender 2.8 problem with textures and or materials
I've been learning blender for the past two weeks, yesterday I was playing with textures and materials, I tried a few like leather, cotton and stuff like that for the pants of the character I'm making, I did not like the outcome so I deleted everything and saved the proyect. Today I watched a few videos to understand more how this works, proceeded to download a few fabric textures to try the same thing again but this time with more knowledge, to find out that something is messing with the textures of my character. I created a new proyect and added the textures to the default cube to see if I was doing the right thing and it worked perfectly. I can't get rid of the colors/textures/materials I have on my character, any ideas on how to do that?
Thanks in advance.
P.S I have attached a couple of photos in case it helps.
This is how my character looks like with the texture:

This is how it should look like:

It's hard to tell without seeing your setup. Have you selected the character in object mode, and then hit the minus button next to the box containing the material slots?

what do you need to see? all i want is remove all textures, colors or materials from my character. Already removed all the materials https://i.imgur.com/IN1uPQ1.png

Yeah, it's very strange that your model is showing colors that "aren't there". Only thing I can think to try is to select your whole character, copy it (ctrl+c), start a new project, delete the default cube, and paste (ctrl+v) your character in. That should clear it of any errant data connected to the old project, and perhaps show you if something is wrong with the settings in the previous problem that may be causing this.

Hi again Christopher ty for your answer, that was one of the first things I tried, did not work though, the problem is that yesterday I was playing around with blender and I'm not sure what the problem is anymore, I'm starting to think that maybe is a texture painting problem but idk

I probably did, but my first thought was that the problem was related to texture or material because sometimes I see  missing textures and materials warnings. Thanks again for the answer

Done I hope this helps ty so much for your time

Hey, I downloaded your file, opened it, changed nothing but switch back and forth between the render settings and render engines (both cycles and eevee) and what I saw was always this. Is this what you see, or different?   - https://ibb.co/SRyn8ZD

yes that's what I see, the problem comes when I add a texture to it, thats when I see the weird blue color, I think it might have a bugged texture or something like that. Idk if you can see it the way I do because u dont have the textures I have but Ill upload the blender file with the texture, the mouth and the nose looks  the way it should https://imgur.com/ZMIuKYK and here is the file

I had to UV unwrap again, but after I added a brick (image) PBR material, I was able to get this - https://ibb.co/R9P7vtQ. FYI, the unwrap was a quick and dirty "smart unwrap" - that's why the texture isn't aligned very well. But before I unwrapped, I used a generated texture coordinate and a checker texture, and got this - https://ibb.co/gdPNBbh. Don't know if that helps any - it's the best I can do for now.

So are you saying that to fix the problem I have to add texture via UV unwrap? I think with the checker texture u have the same problem I have but not with the other one

Yeah, as far as I can tell it only has one UV map associated with it and it looks like this - https://ibb.co/j6fPgFN. The checker texture is procedurally generated so it doesn't need UV's. I think it should be straighter than that though, but I'm not sure.

forgive me Christopher my knowledge about blender its still  bad, Is that good? The thing I dont understand is why the mouth and the nose works fine, i think i might painted the whole model but those spots where the texture works just fine

Yeah, I guess you could call it "bad" - bad for texturing with images at least. When properly unwrapped, it should look more like this (but better because as I said I did a "quick and dirty" unwrap using "smart uv project" - an automatic unwrapping function that doesn't always look so good) - https://ibb.co/Qnvys3k. If you want more info on unwrapping, I've always found this guide helpful - https://artisticrender.com/the-definitive-tutorial-to-uv-mapping-in-blender/

What a bummer, I was thinking about start over again but believe or not this took me a lot of days to do, I was hoping to find a fix for this because I'm kinda close to my goal. Thanks again for your time Christopher I'll try to keep digging for a solution :)


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How to fix these weird shadowy sun rays on the spoon?
I'm quite new to modelling, and I got this pesky problem on the spoon, or maybe I shouldn't care about it? Anyways, at the bottom (same from above) we can see those rays that don't look nice, I tried lifting the faces to even it out, but no luck. Any suggestions?

Heres now I usually go about solving this issue:
I start with a UV sphere with subsurf, and it has some wrinkles:

Heres what the geometry looks like:

Now, i add in a smaller loop cut close to the center of the circle, making sure to position it to maintain the curvature of the sphere:

Now, my wrinkles are gone, or at least imperceptible from this distance:

I hope this helps!

ah man I totally forgot about the loop cuts, but I've already did the subdivision surface modifier, so I guess I'll keep this in mind the next time I see it. Thanks.

Looks like you started modeling from a UV sphere, and that part used to be either the bottom or top of it, and a bunch of triangles meet there in one vertex. Or, there's an n-gon there. (guessing)
You could try to remesh the object by going into the Properties Panel > Object data Properties > Remesh, set your desired voxel size and click Remesh. It should create a nice quads only mesh for you.

Thanks for the help, turns out it only needed a simple loop cut.

source: Stack Exchange

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

sort: votes


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How can I apply a different material during / after using "Solidify" modifier?
I'm trying to turn this apple into a walking character, I have solidified the whole apple, including all 4 peels. Since the solidified mesh can't be edited, I tried to extrude the cut pieces, but it didn't work for me. There's more explanation below this image. Also, I have posted last image as a desired result.

     .
As you can see, after I applied the solidify modifier, it added the thickness just what I wanted (it has weird bumps, but I think I'll fix it), but I can't edit the newly generated layer since it isn't part of the mesh. This way it looks distorted and the cut piece should have that juicy yellowy part beneath the skin. Also, the inside of the apple should be filled with the edible part too, seeds aren't necessary, though I'd love to learn how to add them too.

      How I want it to look like:

https://blender.stackexchange.com/questions/67842/how-to-apply-uv-mapping-post-modifier might be relevant

Your question is not clear enough, but if you want to keep the Solidify modifier (and not Apply it) and give the inner faces a different material, you need to go in the Solidify modifier and use the Material Index Offset, left value to set the color of the outer surface, right value for the color of the inner faces, 0 will mean it will use the first material of your material stack, 1 for the second material of your material stack, and so on.

Yeah, that's basically what I meant, I'm still new to these things so sometimes I don't know how to ask. Anyways, it worked! - https://imgur.com/a/SBQhYZg. Dunno if rigging those solidified objects (apple peels) for animation will have any undesired effect, but I'll try that soon, thanks!

For recent version of blender, same can be done with similar manner.
User the Rim < Materials < Solidify to select the material for the Thickened edge.

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


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Putting an image texture onto a selfmade object
So what my new Problem is, is that im trying to add the texture u can see on the left side on the picture here:

to ma knife, and the first row should go from top to bottom on the left side, the other one from top to bottom on the right side. If i add that image texture now, it looks completely muddled up.
Can somebody arrange the picture to fit the knife?
Heres the Download link for the Texture and the Blender Knife...
https://drive.google.com/open?id=1qK4hvAY_Ivl-L5L4dlWAW2mz8pjgnP4Q
Thats how i want it to look like:

Hello and welcome "Can somebody arrange the picture to fit the knife?" This site is more of a learning tool than a "fix it for me" forum. Could you rephrase the question so that it focuses on solving the issue rather than have someone do it for you? Also have a look at other questions about texturing on the site, this is a very basic question that has been tackled many time before

i need an example file to find it out on my own... so any help would be appreciated. Ill just need that one time.

Hello :). There are many, many issues with the model. I'll adress them in a full answer, including tips on a proper image texturing.

as long as its understandable imma try and redo it  then ;)

Thre's no need for so much seams.
A very simple UV map is enough.

(Repair the mesh - more steps below) :)
Add just a few seams where needed
Use the UV editor to position the UV map
Set image texture to Clip - so it's not repeated across the model.

Using just one material is very limiting, but sometimes needed.
Use more materials if you want different color on your mesh.
Example of a proper UV unwrap

How to repair the mesh:

Apply object scale and rotation through Object > Apply > All transforms
Remove stray and connect unconnected vertices/faces/edges
Make the mesh manifold (watertight)
Correct face orientation through Mesh > Normals > Recalculate outside
Delete the old UV map entirely

Here is a repaired .blend for inspiration.
Yours might look a bit different, but that doesn't really matter :).

thank you. the problem now is that u removed the holes :/

the original shape is now gone...

Sure, it's just for inspiration :). It will work the same with holes in the knife.

i dont really understand how to use that uv mapping. im a complete beginner.

In that case, perhaps start with some simple beginner tutorials on YT :). These things are way easier to explain through moving images. Good luck.


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Texture Painting not working on some parts
Sup. I made a Knife Model recently, and tried to texture paint on it. The Problem is, that there are Parts where it works and parts where it doesnt, and only changes the solid color if I paint somewhere. If I open it as OBJ there is a different part which is just black and cant change the color. Is there a way to "rasterize" the object as in Photoshop, so i can paint all over it? And yes, its a single mesh i guess...
Try Texturing all over it please: https://drive.google.com/file/d/1AOTmQfrKYmQ0X-Pz1rQ9HU_E_SLflNA1/view?usp=sharing

Its because your mesh is not unwrapped correctly. Check out this link to know how to unwrap a mesh -->  Painting a dog with texture paint, TOTAL NOOB

I've tried unwrapping your mesh but the sword shell mesh was not good, its mesh was overlapping. So i've just unwrapped blade and handle.

1st mark the seam using Ctrl+E and then U and Select Unwrap.

This is how a mesh is unwrapped. It should not be overlapped, unless you want same texture on it.

I'm not a teacher but here are some Remarks after seeing the mesh :
Try making different objects in this case eg., sword,shell,handle etc.,then and after its texturing is done (or) applying the materials, join the objects into single object using Ctrl+J. Don't make everything in same object from the start.
Hope your problem is solved.

damn thats a great tutorial, would u be down to send me the file?

hope u saved it :O

https://blend-exchange.giantcowfilms.com/b/Q7X8XS5d/

but unwrapped only for blade and handle as shell was overlapping..


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glTF 2.0 Validation error: ACCESSOR_VECTOR3_NON_UNIT
I’m getting an error from a .glb file that was exported from Blender using the Khronos glTF Validator. I’ve been searching online for the past couple of days, but can’t find any information describing what this error is all about and how I might resolve it. I’m fairly new to 3D modeling so any help to point me in the right direction would be greatly appreciated. Here is a snippet from the validation report:
{
“code”: “ACCESSOR_VECTOR3_NON_UNIT”,
“message”: “Vector3 at accessor indices 4830…4832 is not of unit length: 0.”,
“severity”: 0,
“pointer”: “/meshes/0/primitives/4/attributes/NORMAL”
}

What I need to know is, what is the error referring to, and how can I find the source of the problem inside Blender so that I can correct it?

Looks like Blender produces a file that doesn't fulfill the specification. Please report this on Blender's bug tracker (Help > Report a Bug in Blender) and attach the project that produces the problematic file when exported. Try to keep the project as small as possible.

This question should not have been closed, as it has a simple answer within Blender:  In Edit Mode, select all, and go to the menus, Mesh -> Clean Up -> Degenerate Dissolve

Specifically, these are zero-length normal vectors, produced by degenerate geometry, which is invalid in glTF.

@emackey Thanks, I went through several of the "clean" options, Degenerate Disolve, Merge by Distance, Delete Loose, before posting this question, and none worked. I eventually discovered an export warning after launching Blender from the command line:  WARNING: Could not calculate tangents. Please try to triangulate the mesh first. I added a Triangulate modier to the mesh and that did the trick.


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Using object's printed name in script
I am trying to write a script that will end up baking materials from a high poly object to a low poly object. The problem i am having is that i will never know the object names beforehand, as my script is importing obj's from a folder into blender then duplicating them and applying a decimate filter to them. So far i have all of that functioning correctly, but i'm stuck on the final part of selecting the low poly at the target object of the bake.
>>> bpy.ops.object.select_by_type(type='MESH')
{'FINISHED'}

>>>
>>> for obj in bpy.context.scene.objects:
...     if obj.name.endswith("001"):
...         print(ob.name)
...         bpy.context.view_layer.objects.active = ob
...
Hat 1.001

>>>

I have the script printing out the name of the object that has a name ending in 001 since i know that my low poly duplicate will always end with that. My problem is that i need to take that printed name and apply it to the next command like this example
bpy.context.scene.targetobj = "Hat 1.001"

I can't figure out how to take the name that gets printed out and apply it like in that example. Thanks in advance.

If you just need the name of the object as a string, then store it in a variable. I'm not sure bpy.context.scene.targetobj exists though.
for obj in bpy.context.scene.objects:
    if obj.name.endswith("001"):
        # store the name into a variable
        object_name = obj.name
        # use the variable
        bpy.context.scene.targetobj = object_name

Worked perfectly and I even found a few other spots I could use the name variable, thank you so much!

Use a pointer property
Can set up a pointer to any blender ID type objects, in this case bpy.types.Object instances of which can be found in bpy.data.objects collection.
Assign the property to class
import bpy
from bpy.types import Object, Scene
from bpy.props import PointerProperty

Scene.target_obj = PointerProperty(type=Object)

Test.
>>> C.object
bpy.data.objects['Cube']

>>> bpy.ops.object.duplicate()
{'FINISHED'}

>>> C.object
bpy.data.objects['Cube.001']

>>> C.scene.target_obj = C.object
>>> C.object.name = "Foo"
>>> C.scene.target_obj
bpy.data.objects['Foo']


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Trouble with getting correct context
I am brand new to both blender and python, so i apologize in advance if i'm missing something simple, but i'm having trouble with my script. The purpose of my script is to hopefully delete the default cube in the scene, scan a folder for an obj file, import that obj and then make a duplicate of the imported obj and apply a decimate modifier to it.
import os
import bpy

decimate = 0.02
resolution = '4k'

bpy.ops.object.select_by_type(type='MESH')
bpy.ops.object.delete(use_global=False)

full_path_to_directory = os.path.join('C:\\', 'Users', 'brand', 'Desktop', 'New folder (2)')
file_list = os.listdir(full_path_to_directory)
obj_list = [item for item in file_list if item[-3:] == 'obj']

for item in obj_list:
    full_path_to_file = os.path.join(full_path_to_directory, item)
    bpy.ops.import_scene.obj(filepath=full_path_to_file)
    bpy.ops.object.duplicate()
    bpy.context.active_object

for ob in bpy.context.selected_editable_objects:
    ob.active_material_index = 0
    for i in range(len(ob.material_slots)):
        bpy.ops.object.material_slot_remove({'object': ob})
        bpy.ops.object.modifier_add(type='DECIMATE')
        bpy.context.object.modifiers["Decimate"].ratio = decimate
        bpy.ops.object.modifier_apply(apply_as='DATA', modifier="Decimate")

bpy.context.scene.render.engine = 'CYCLES'
bpy.context.scene.selected_col = True
bpy.context.scene.selected_rough = True
bpy.context.scene.selected_normal = True
bpy.context.scene.texture_res = resolution
bpy.context.scene.restoreOrigUVmap = False
bpy.context.scene.newUVoption = True

When i run the script, i get this error
Traceback (most recent call last):
  File "\Text", line 24, in <module>
  File "C:\Program Files\Blender Foundation\Blender 2.81\2.81\scripts\modules\bpy\ops.py", line 201, in __call__
    ret = op_call(self.idname_py(), None, kw)
RuntimeError: Operator bpy.ops.object.modifier_add.poll() failed, context is incorrect

However, if i delete the section that handles importing the obj from a folder and i simply apply the script to the default cube, everything works correctly and i get a duplicate with a decimate filter applied correctly. I have tried a few different ways of trying to fix this issue but i just cant seem to wrap my head around it, any help would be greatly appreciated. Thanks.

Add modifier using API, override the modifier apply.
Would use
m =  ob.modifiers.new(name="Foo", type='DECIMATE')
m.ratio = decimate

to add a modifier, and override the context of modifier apply operator, just as you have done for material link remove.
bpy.ops.object.modifier_apply({"object" : ob}, apply_as='DATA', modifier=m.name)

Questionable whether you want to add and apply modifier for each material slot, check your indenting
Alternatively can deselect all,  set as active and select the active object in loop.  To set the context to each individual object. Suggest is the Equivalent of you "simply applying script to default cube"
Eg for 2.8
bpy.ops.object.select_all(action='DESELECT')
ob.select_set(True)
context.view_layer.objects.active = ob

to give the loop object context.
However would recommend using as few operators as possible...  see Python performance with Blender operators
Note incorrect context is a common cause of problems
https://blender.stackexchange.com/search?q=context+incorrect

I'm sorry to do this, but could i bother you with another question regarding this? In my script i'd like to get it to bake the materials from the high poly mesh down to the decimated low poly which requires me to have the original high poly mesh active and the low poly duplicate as the active object, but i can't seem to make that work. Sorry for continuing this, and thank you so much for your previous answer, it worked perfectly and actually helped me better understand how things work. Thanks again.

Can select as many objects as you like by setting select. Equiv of context.selected_objects Can only have one active object.


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Converting edges to curves and then beveling them causing weird geometry
I made a cube and then added edge loop, deleted faces and unrequired edges and got this
Afterword I converted it to curve so I can bevel it but I am not getting proper results on 2 ends

Is there a way to solve this or an efficient way to make a wooden fence like this?
Thanks in advance. I am fairly new to blender so this could be a dumb question.

The problem has a similar source as this one: Curve to mesh bulges at intersection, although there it is about GeoNodes. The issue is the same: too low resolution on the curves. They have endpoints and only point inbetween building a 90° angle. In this point the tangent is 45°, so the profile does not have the same height and width in vertical and horizontal direction as the endpoints. You either need more points towards the corner or set the curve to 2D, but this flattens it on Z.

Or you could have separated the edges before converting them into curves, then you would have only straight curves without any angle where this happens. Or you do not convert the mesh at all and use a Skin modifier.


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Can not find Transform -> affect only origins anywhere?
I cannot find the affect only origin for transformation anywhere check the image below -

I am using blender version - 2.93.6

You are probably in Edit mode, you need to switch to Object mode:

Thanks a lot , I am new to blender and didn't notice i was in edit mode , i even watched 30 min of videos and read manual on how to change origin but couldn't find the option.


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Animation render screen is black for the first few seconds
Half of the screen is black in the render for the first 3 seconds.

Here is the link for the animation, its only 4mb.

Here is the link to the blender file . Thanks in advance.

Does this answer your question? Number 6

It looks like it's caused by the object called Plane, your camera is at the middle of it:

Yes I added it just for reference and thanks a lot !!!


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What base color should I set when making emission or transmission effect in Principled BSDF?
It seems like base color will have some effect on the material, even I aim to make an emission or transmission effect.
I would like to know the physically proper way to set up my material.  According to Blender's official manual, base color represents diffuse or metal surface color. Hence, I think I should avoid using base color when making emission or transmission effects.
Is leaving base color black a proper way? Or should I do some specific setting?

Hello ! If you're not going to use the principled capabilities, you might as well use an Emission, Glossy, Glass, Refraction or Translucent shader

The base color affects light reflected by the surface.  If you want untinted transmission, set the base color to an RGB value of (1.0, 1.0, 1.0).  Any other value will tint the result, like tinted glass. This works precisely the way that photographic filters affect the light passing through them.
Because it only affects light reflected by the surface, the base color does not affect emission directly.  If you make the emission strength high enough compared to other light sources, you will see nothing but that color.  If you make the strength lower, you will see a combination of reflected light plus emission.


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Render a Panorama with Room Outlines with panorama camera
I have a simple room, a camera inside and a Panorama-Camera for creating a 360° Panorama Render. That works fine.
I want to have only the outlines of the room-walls (and later stuff like a table inside) rendered like comic-style. I tried different technics like freestile and Line Art, but they have limitations and none of them works in panorama-camera only in perspective and eevee randerer.
is there any solution for this problem in Panorama-Camera?

are you really sure that freestyle line art doesn't work in panorma-camera? i didn't try out but i cannot believe...

yes, its written in the manual of blender


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Water Volume Density Changes 3D View Port
I am trying to make a liquid in blender, and when setting the volume density it changes the color of my view port entirely.

Hi there :) Can you share your .blend file. Thanks

@Nxdhin2005 How do I share it via the comments?

Upload it either in the ggogle drive here-https://blend-exchange.giantcowfilms.com/. Just edit your question and add the file

It says the file can't be bigger than 30MB. @Nxdhin2005

Then try uploading in Google drive and create a sharable link...I guess it is a bug. Not sure though

I forgot mediafire was a thing, and I don't know how to use google drive uploads since I never used google drive. Here is the link: https://www.mediafire.com/file/mcm1wv01s1dqwc1/Cup.blend/file

I don't experience any issue while using your file even i added in a volume absorption node in the materials preview mode . It is a bug... In the rendered view however I guess you wont have such problems. Materials preview mode has many bugs in certain hardwares. For example see this qn- https://blender.stackexchange.com/questions/186618/why-dont-my-materials-reflect-hdr-images?noredirect=1#comment312757_186618

You can complain your issue at- https://developer.blender.org .Also try using the latest version of blender.

I am using the steam version, and it doesn't show that it has any updates. Also I will be sure to report the problem there if it isn't already.


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Animate armature from 3d joint locations
I have a simple human armature that I am trying to animate based on real-world 3d coordinates. These are coordinates of 21 distinct joints in (x, y, z) format. Based on the way that I generated my data, I cannot guarantee that the bones are globally the same length, but I assume that it will be close. To combat this, I produced an armature that has a parented joint structure, but where the bones are disconnected. It looks like this:

I want to set the bone head and tail position of every bone in my armature, and then animate it from the data that I have using the python API.
I have a super simple script that I am working from to read in my data and assign the proper objects. I was attempting to assign positions to head and tail, but I see that the pose_bones are read-only for those objects. Thus, I created a few extra bones and just set .location to see if I could get my bones to move. My script translates all of my bones, but every frame appears identical (not to mention extremely disconnected) - even though my data is not constant in every frame.
Here is that script:
with open('frames.json') as f:
    frame_data = json.load(f)

# frame_data is a dictionary of dictionaries that looks like this:
# {'frame_0' : {'joint_name': (x, y, z), ... }, ..., 'frame_n': {} }

rig = bpy.data.objects['metarig']

for frame_num, joints in frame_data.items():
    bpy.context.scene.frame_set(int(frame_num))
    for joint_name, joint_positions in joints.items():
        if "hand" not in joint_name:
            rig.pose.bones[joint_name].location = joint_positions
    rig.keyframe_insert(data_path="location", index=-1)

I assume that I am accessing the wrong object to update positions, or that I have to switch back and forth between edit mode and pose mode in every frame, but I am not sure where to turn.
When I run my code, I get some craziness that looks like this:

I am suspecting that the giant gaps are because I am not updating the head and tail positions. How does one do that explicitly? And is there any reason in particular why every frame is identical?
I am completely new to blender, and this is the first time that I have ever done a project with the software, so I apologize if my question is a little elementary.

I'm working on this exact question.
I have thought about calculating the translation and rotation matrices between each frame and then applying that transform in POSE mode. Doesn't work out exactly since I haven't figured out how to get the inverse homogenous rotation matrix.. Some things I've come to realize. You need to be in POSE mode to edit the pose, EDIT mode to edit head and tail (which is relevant to your joints), and OBJECT mode for keyframes (I think, not sure on the last one.) Location is also different from head and tail So far the bpy.struct for PoseBone has been really

possibily this is due to the way bone are encoded in the input file. The way blender defines bones is not (always) the way other software does it.


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the convex and concave lines on the PDF
I am trying to make a paper template to make a 3D paper model. when I export the model with the paper model add-on it only shows solid black lines, I can't tell which needs to be folded in or out. even when I specify to have anything but solid lines, like a dotted or dashed line, the PDF still only has solid black lines. if anyone knows how to specify on which way to fold the crease and to have it shown on the PDF it would be much appreciated.


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Connect points of motion tracks with (smoothed) lines
I am tracking motions with blender, and adding motion trails to tracked objects. With hq slow motion footage, just attaching an empty vert with a particle effect to my track works very well. However, when the frame rate is not very high, the tracker will be quite far apart frame to frame and I end up with what looks like a dotted line because the emitter jumps from one tracker location to the next. I would like to bridge the gap either with more particles or just a line.
How can I distribute more particles between the current and previous/next tracker location? Maybe I have to convert the track into a path or a line (I can't figure out how)? Basically what i want to achieve is a smooth gap-less motion trail even when the tracked object moves quite a bit between frames. Grateful for any advice, thank you.

Thanks. I think this is a good and practical solution for shorter paths, however mine was a bit too long and complex to manually add and shape a beveled curve on top of it.

Thanks for your reply.  I've only recently pulled that link down but it's back again as a new one.  Take a look, you might be surprised how effective it is.
New link -
https://www.dropbox.com/s/qi2r3adoz661noq/Trail.gif?dl=0

You can do this with Animall (Addon, has lots of presets), but I always found it a bit wonky and it's not really migrated to 2.8 yet.
With a little more effort you can use Animation Nodes for that, in the end you have way more control over the behaviour of your path. Here's a screenshot of my Nodetree, note that the dotted line is just the visualized motion path of the empty, the selected curve is the actual offset. I moved it to the side, so you can distinguish between them.

You can probably clean the tree, or not use a loop, but this way works. Note that if you have more than just location keyframes on your object, the list indices might change.

Thanks! I'm still working on it and generally understand what you're doing here.
I managed to recreate your node tree, and now I'm trying to use it properly.
Things that I'm still unsure about:
Is it correct that this 'program' runs in advance to set up the path for the lines or particles? (as opposed to extending the curve frame by frame as the img sequence plays).
Your example would be able to set up a 25 frame animation? (25 iterations)
Is it correct that the Empty object that is the input should be a child of my tracker?
I'm not able to manipulate a bezier curve (output) yet.

It took me a while, but I found a solution based on this. I struggle with nodes, so I sort of translated this network into a python script. It took me a while to properly create the keyframes and connect my objects to what the node network is doing. But in the end I think I ended up with pretty much the script version of this.

Tracking information creates a constraint.
To convert constraints into keyframes, open the constraint section of the properties window and press Constraint to f-Curve

The tracking information will be converted to keyframes, the curves for those keyframes can be displayed and manipulated on the Graph Editor.

There are a few built in tools to clean up curves in the key menu of the Graph Editor.
Here's the same motion path after applying the "Clean Keyframes" function:

Thanks, this was definitely a missing step in my failed attempts!


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How to convert from vertex_color to material and export FBX file
I have some problem with my blender code export to fbx file. I set color by vertex_color and set mode is Vertex_paint. But when I export this object to fbx file and open in Unity it is not include color. I think the reason might be dont set color for material of object. So could you help me to convert ?
This is my code. Thank you so much for your help
import math

# mesh arrays
verts = []
faces = []

# mesh variables
numX = 10
numY = 10

# wave variables
freq = 1
amp = 1
scale = 1

#fill verts array
for i in range (0, numX):
    for j in range(0,numY):
        x = scale * i
        y = scale * j
        z = scale*((amp*math.cos(i*freq))+(amp*math.sin(j*freq)))
        vert = (x,y,z)
        verts.append(vert)

#fill faces array
count = 0
for i in range (0, numY *(numX-1)):
    if count < numY-1:
        A = i
        B = i+1
        C = (i+numY)+1
        D = (i+numY)
        face = (A,B,C,D)
        faces.append(face)
        count = count + 1
    else:
        count = 0

#create mesh and object
mesh = bpy.data.meshes.new("wave")
object = bpy.data.objects.new("wave",mesh)
#set mesh location
object.location = bpy.context.scene.cursor.location
bpy.context.collection.objects.link(object)

#create mesh from python data
mesh.from_pydata(verts,[],faces)
mesh.update(calc_edges=True)

vert_list = mesh.vertices
color_map_collection = mesh.vertex_colors
if len(color_map_collection) == 0:
    color_map_collection.new()
else:
    color_map_collection.active

color_map = color_map_collection['Col']
i = 0

for poly in mesh.polygons:
    for idx in poly.loop_indices:
        loop = mesh.loops[idx]
        v = loop.vertex_index
        final = (0.1,0.5,0.2,1)
        color_map.data[i].color = final
        i += 1

bpy.context.view_layer.objects.active = object
bpy.ops.object.mode_set(mode='VERTEX_PAINT', toggle=False)

Do the colors look like you'd expect in blender?
Unity doesn't read vertex color by default, you have to enable it. Also when you build, you need to enable vertex color under the mesh optmization options.
Other than that I never had troubles with vertex color and fbx.

HI @FrederikSteinmetz absolutely, I would like to make the color look like blender in Unity. Thank you for your reply. Btw if you have any document or example about how to enable vertex color under the mesh optimization options in blender/ even Unity, please share for me. Honestly, I pretty fresh in this field. Thank you

before I do this, do you have a shader that handles vert. col. in Unity?

Your mean is vertex and faces define? Sorry for my silly question. Because I am not clearly understand "shader".

You won't see any vertex colors in Unity, unless you have a shader (material) that can read them.

Actually, this is my matter, my code just work with vertex colors and I dont know how to add vertex colors into material ( sorry if something wrong). So I run within above code and in VERTEX PAINT mode I can see color perfectly. But when I export it to FBX and import those FBX file into Unity, the color can not appearance.

How are you checking if the colors get imported in Unity? What do you want to do with them?

So I just import it into Unity and my expectation is look the object with full color. But I can not. I just read FBX file in Unity without any set up.

Unity is a game engine, not a vertex editing engine. While you can build or download tools to edit meshes inside of Unity, I'd advise you to stick to Blender for that. Unity displays everything similar to Eevee. If you assign a default material to an object in Eevee it also won't show vertex colors, unless you tell your material to read them. In Blender, you need a built-in node for that, in Unity you need a shader that can read and display them.
https://forum.unity.com/threads/finding-and-using-a-vertex-colors-shader.236366/
Unity will also omit any vertex color information in the build, unless you tell it to keep them.

This option is in the Player Settings.

Thank you for your support, I actually import fbx within color into Unity

if it helped yout, would you mind accepting my answer?


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Sprinkles are turning out different in rendering than they are in the view-port?

I'm just learning Blender, so bear with me if this solution is simple. The first image (the screenshot, through the camera) is what I want, but when I click to render the actual sprinkles on the donut become super small.

Any chance you use Compositor, and is there a node(s) affecting the sprinkles particle system? That's what's likely to affect your render.

All I'm using is the denoise node in the compositing tab.

Try to plug the viewer node into a node before the denoise node, then tell me how is it

I think I figured it out, the scale function in the particle properties had a keyframe, I think it was animating itself from a smaller to a larger size but I couldn't tell because I would only render one image. I just turned the keyframes off and now the sprinkles seem to be fine.


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Blender Is Not Rendering, Why?
I'm trying to render an animation, the problem is Blender is not rendering anything. The CPU is not working at all, what to do?
Here's the file that I'm trying to render: This.

Please don't make the question depend exclusively on others downloading your file and reverse-engineer what you did. Edit your question and explain clearly what you've done, add images of your render and output settings.

You don't have a file format to output. You have a location but there is no output format. You need to choose .jpeg, .jpeg movie, MMPEG.... however you want you output to be.
It's in the output tab right above colors under "File Format" underneath where you select your output folder.
What version are using and which render are you trying to use: Blender, Cycles, Evee, Workbench..

I've set the file format, the output folder, encoding...etc. My Blender is 2.83 LTS and the render engine is Evee.

You can try to change your output folder, and below that three lines down change your "FILE FORMAT" so Blender knows how to output.
Other then that I think it's trying to render your "FIRST MONITOR" which is nothing. All your information is on the second monitor. I can get it to "render" but there's nothing to render.
What I don't understand is why it's all black. Unless this is just Blenders way of saying I have nothing to render. It's actually popular in game programming IDE'S.
Unfortunately, I'll have to take a closer look a bit later. Good luck mean time.


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blender closes on startup
I'm using an i9 desktop computer and a graphic card of Intel® UHD Graphics 630 with a Quadro rtx 4000. Currently I'm using blender 2.83 but anytime I try opening it, it shows me a black screen an it immediately closes. it doesn't open, please what do I do.
many thanks

Do other versions of blender open?

yes, blender 2.67 below which are really older version. I recently tried to get others ones to work but it keeps doing the same thing.

If all drivers are up to date, this could be an issue similar to T72098. If you're using Windows try to use the workaround described in this ticket.

Start blender from a terminal.  And see if any errors show up.
https://docs.blender.org/manual/en/2.79/render/workflows/command_line.html
Platforms
How to actually execute Blender from the command line depends on the platform and where you have installed Blender. Here are basic instructions for the different platforms.
Linux
Open a terminal, then go to the directory where Blender is installed, and run Blender like this:
cd <blender installation directory>
./blender

If you have Blender installed in your PATH (usually when Blender is installed through a distribution package), you can simply run:
blender

macOS
Open the terminal application, go to the directory where Blender is installed, and run the executable within the app bundle, with commands like this:
cd /Applications/Blender
./blender.app/Contents/MacOS/blender

If you need to do this often, you can make an alias so that typing just blender in the terminal works. For that you can run a command like this in the terminal (with the appropriate path).
echo "alias blender=/Applications/Blender/blender.app/Contents/MacOS/blender" >> ~/.bash_profile

If you then open a new terminal, the following command will work:
blender
MS-Windows
Open the Command Prompt, go to the directory where Blender is installed, and then run Blender:
cd c:\<blender installation directory>
blender

You can also add the Blender folder to your system PATH so that do you do not have to cd to it each time.
You can also try to reset user preferences (this will reset blender to stock)
https://www.katsbits.com/codex/userpref/

thanks rick, I just tried it. it told me Failed to set 48000hz, got 44100hz instead,  Error : EXCEPTION_ACCESS_VIOLATION Address : 0x0000000000000000. please how can I fix it

@TamiloreJoseph  Ok try the answers in this link start with the second answer first.
https://blender.stackexchange.com/questions/77857/error-al-lib-updatedeviceparams-failed-to-set-44100hz-got-48000hz-instead-wh#
And be sure to save the settings then reboot your machine.

thanks, it doesn't work either, I've tried it

Mine was actually the opposite , in the comment it was failed to set at 44100hz, got 48000hz instead. the only version that works is from 2.67 below

You may want to file a bug with the developers they are really good a narrowing it down. https://developer.blender.org/

@TamiloreJoseph -- don't forget to check the check-mark on Rick's answer if it helped you.   Some of us humbly work towards more "reputation points"!  It also helps others to find "accepted answers" that then help in solving their similar problem.


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Some objects not showing in object mode
I am a newbie in Blender 2.8. Some of my objects stopped to show up when I switch to "Object mode". What is going on? Thanks for a great forum.

Hello, this is not part of the question but you are definitely not showing screenshots from the 2.8+ versions.

Sorry. 2.79 :-)

You are using a boolean Intersect with another object. My best guess is that there actually is no intersection between these objects and the resulting geometry is empty. :) Try deactivating this modifier and see if the geometry appears

Not a bad guess at all! You solved it. Thanks a lot!!!


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Choppy video even with 'Lossless' settings?
I'm using Blender 2.82's Video Editing pane to create a video from a series of images (also generated in Blender).
No matter what settings I use, I am unable to create a consistently fluid video. Although some sections are smooth, there will always be bits that are choppy (seemingly at random times).
Image sequence:

5000 images
PNG format, generated by Blender
Dimensions: 1920 x 1080
Size: ~3.68 MB each
Bit depth 25
Compression: 15%

Output settings:

Frame Rate: 24 fps
File Format: FFmpeg video
Container: Matroska
Video Codec: H.264
Output quality: Perceptually lossless
Encoding Speed: Slowest

What's more, despite the choppiness, the output file is huge (2 GB for a 3:22 minute video).
Any advice on generating a smooth video? What would be an expected file size? Thanks.

Does the image sequence look correct in the preview before exporting? Or if you use encode the image sequence directly to video with ffmpeg? https://stackoverflow.com/questions/24961127/how-to-create-a-video-from-images-with-ffmpeg https://superuser.com/questions/624567/how-to-create-a-video-from-images-using-ffmpeg#12160155


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Subdivision sharpening random edges
Transitioning from Maya to Blender, I'm working on a mesh in Blender 2.8 and when I apply a subdivision modifier all goes well except for one section, which seems to have frustratingly weird, sharpened edges. All vertexes and edges are merged properly, and the mesh is all in quads, what is going on here and how can I get it to smooth properly like everything else?
I attempted "merge by distance" just in case but this doesn't affect it at all.
Thanks in advance for the assistance!

Check if your normals are correct...

This looks like double vertices issue. In opposition to Maya you actually need to select all vertices in order for "merge by distance"to work. Alternatively you could try "Clear Custom Split Normals" operator.

Recalculated normals and it was fixed. Thank you!


text:
alt+rightmouse shortcut
hope you are all well during this difficult times.
I just downloaded version 2.82a for Linux, and I was trying to follow a tutorial on how to make a photo realistic ring.
Mind you I never used Blender before,so I'm a complete novice, but since I am stuck at home as my workplace is closed, I thought I'd give it a go.
I managed to do the first ring, but as I was trying to do the second one,the guy was saying to use alt+rightmouse to select the section to extrude.
He was using an older version 2.76b, and I cannot find the same function on the newer version.
I have checked preference-keymap-select using right, saved it restart the software but is still not working.
Anyone know the right shortcut, or can point me in the right direction?
I have attached a screenshot of the point where I am stuck
Please bear with me if this is a silly question
Thanks

Hello :). This seems to be an ongoing issue with Linux https://blender.stackexchange.com/q/60961

Thanks.
Was so focused to find a solution in Blender that I didn't even think about changing the key function in Linux.
Disabled the key on Linux, as I don't used it anyway and now the shortcut  works in Blender :)

Happy to help, and welcome to Blender :).


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Issues with 2.82a Mantaflow Fluid - Am I the only one?
I've been working with the new Mantaflow Fluid Simulator and have had some successes and a lot of FAILURE.  Thanks to the awesome tutorials by Blender Mania, CG Geek, Jonathan Kron, Blender Made Easy, I have been able to create some very nice Fluid animations.  (I also READ the on-line manual at Blender.org).  Here are the issues I am having and would like to know if others are having them also (operator error or bugs?)

After successfully creating a very simple simulation (1 cube as the flow, 1 cube as the Domain) I decide I want to change the size of the domain.  I scale it up, Free the Data - re-Bake - No particles.  No matter what I do now, I cannot make the particles reappear.
If I DELETE the Domain Cube, recreate it, RE-Bake, the particles reappear but remain INSIDE the Flow Cube (geometry)
Delete the Flow Cube, re-create it, rebake, all works again.
Scale up the Domain - Works (second domain cube)

Next Issue...

I create a beautiful Fluid Animation with water materials, Spray, Foam, Bubbles, particles, Environment, effectors, etc. Save the Blend file.  When I reopen, nothing works.  Animation wont play, Rebake does not work, and the Domain is filled with a haze.


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How to make this petal shape a mesh?

I am trying to make the petals in this image I made in illustrator in Blender but making it into a mesh that I can solidify so it looks like a 3d ring of petals that come out. How do I make this shape in Blender by itself?
whenever I import it as a svg just hte flower poath it creaste a hollow design. I am clearly very new to all this would like some help please!

Fill those petals in illustrator and after you fill that in illustrator application you will be able to fill that


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Made a mistake weight painting now i cant reset weight values of bones to the automatic ones
Im new in blender and i was tryign to rig arms for my 3d project but they would deform a lot. I tried a lot of things, one of them changing weight painting from the automatic one. But now i realized i made a mistake there and i want to reset the values to the original ones.
I searched in this page for a solution, i tried selecting the bones, typing spacebar, search weight from bones -> automatic but blender would lag and after that say that that it was not possible to do that.
i ve been a lot of days stressed trying to find a solution i would appreciate if someone could answer

You can remove all the vertex groups from the object then try automatic weight.
You can select a vertex group and press the "-" button or press the "special button" (marked red) and select "delete all groups".

Please explain how to remove vertex groups from a mesh ideally with an illustration of the procedure


text:
Create a plane from contour lines
I'm new to Blender and am experimenting using it to design a landscaping project. I have a DXF file with contour lines for the land and have managed to import these into Blender. My aim is to have a full surface that reflects the site, and where I can start manipulating the slope and adding shapes onto it.
I now have a series of lines with heights, but that are not connected to each other and don't have an edge around them. After a long time trying to just join the edges using a combination of selecting them and choosing "Connect vertex path" or "Merge vertices > at center" (when connect didn't work) I thought maybe I'd be able to create a plane from it. However this only created small patches of planes so I'm guessing I've done something wrong. I was thinking as a next option I could just create a plane of the same size underneath it and manually drag each point up to match a point on one of the contour lines. This would probably take quite a while - is there any better option out there?

Hello :). This is called Point Cloud Skinning. Here are some threads covering this: https://blender.stackexchange.com/q/167866/, https://blender.stackexchange.com/q/7028/, https://blender.stackexchange.com/q/111141/

Apart from the point cloud skinning (which is not built into Blender well), have you tried simply selecting all [A], making a face [F] and triangulating [Ctrl T] ?

@Leander I tried creating a face, but it doesn't work well as it results in just a few spots with faces (like in the image I posted). I was trying to use the point cloud skinning but I'm using 2.82 and I don't see the "Point cloud skinning" option in the scene panel as I would expect from the documentation for the add-on. Maybe it's not compatible with this version?

I tried shrinkwrap the method suggested here and it seems to work pretty well. Thanks @JachymMichal !


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object with low vertex bend like having high vertex
this is a leg of a fox in mcprep add-on
it dont have many vertex as you can see. when i move one or some vertex, it didnt work like normal but act like this. i want to know how to make an object/model like this one then i can later make other things similar.
Any idea ?

Looks like a subsurf modifier.

ah, thanks ! thats it. in wireframe view it have more edge.

Note that the pink edges have a "crease" value of 1. That means the geometry will try to get as close to the actual unsubdivided mesh as possible. To tweak the crease value, select at least 2 connected vertices and go to the right panel > Item > Transform and tweak the mean crease

@Gorgious wow, thank you so much ! I've learned a lot today.


text:
bump-mapping or something else?
Maybe you guys can point me in the right direction. I want to create glass vase and have on it something like on the picture below (random pushed dots?) but I cant do this in Solidworks. So I was thinking to export stl file to Blender and do this in it. What is the best way to do it? Will appreciate any help. Thanks

Does this help ? https://blender.stackexchange.com/questions/58493/how-to-create-procedurally-generated-surface-bubbles-on-a-liquid

I will check it out. Thanks

Do you need to 3D print this? .i.e. Do you want the displacement in the geometry, as well as the render?


text:
Snap bone back to an offset relative to another bone
I am creating a reload animation for a rifle where the left-hand needs to move to grab the magazine and replace it. I currently have the magazine set up with a child of constraint on the left hand so the mag will follow the left hand when it needs to. However, I need a way to snap the hand back to the holding position on the rifle after the reload has ended. Copying the keyframes on the left hand when the rifle was being held doesn't allow me to snap the hand back to the holding position if the rifle isn't in the exact same location/rotation as it was at the copy. Is there a way to dynamically do this?
This is the resting position I would like the hand to return to    (relative to the rifle location/rotation).

This is when I would like to snap the hand back to the resting position shown above considering the rifle's new location/rotation.

Consider adding another Child Of constraint, but put this one on the hand itself, and for the target, make an empty or bone that has been placed near the hand rest position (and which is also parented to the gun). Keyframe the influence slider for this "hand rest" Child Of constraint so that the slider is in the fully off position when the hand is currently reloading, and then keyframe the same slider so that it is fully on when the hand needs to be at full rest under the gun. The influence slider will interpolate smoothly when keyframed, so the hand will gradually become more and more the child of the empty or bone under the gun as time progresses. If this looks wonky animation-wise, you could leave the influence off until you have keyframed the arm manually returning to the gun, at least until the hand is very near to the gun. Then you could keyframe the Child Of constraint influence slider to be fully on only at that point. You will still get the advantage of knowing for sure that the hand will end up in the final rest position, where it belongs.

I'm assuming that the hand is leading an IK chain. If so you can use shift S to put an empty in the exact loc of the hand in fig.1, copy the hand bone rotation, set the empty as child of the gun, then set a copy transform bone constraint on the hand, pointing at the empty. In this setup you can animate the influence slider of the constraint, so that when the influence is 1.0 the hand is on the gun, when the influence is 0.0 the hand is free to move.

I've tried this and the Child Of constraint method, but I am getting some odd rotation with both methods when the hand constraint influence is on. The rotation on the empty matches the rotation of the bone in its posed state. Do you happen to have any idea why? The location matches, it's just the rotation. I am using quaternion if that's relevant.

Lots of orientation weirdness can occur, and is hard to diagnose blind. Share your file? https://blend-exchange.com/


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Copy Transform Constraint Wrong Rotation
I have created an empty to hold the relation of the resting position of a bone to a weapon. I am setting a copy transform constraint on the hand IK with this empty as the target. The constraint matches the location of the empty correctly, but I am getting odd rotation.
This is the hand IK (with mesh hidden) and empty. The empty is parented to the weapon.*

This is the resting position that I am trying to achieve with the empty and copy transform constraint. This is so I can set the hand to the resting position relative to the weapon.

This is the result I get when adding the constraint with the empty as the target. Not what I want.

I have tried matching the rotation of the empty to the rotation of the hand_ik in pose mode, but that gets me the results shown above. My best guess is this has to do with how quaternions work, but I don't know how to go about fixing it. How can I set the empty rotation in such a way that the hand will have the correct resting rotation when I add the copy transform to the hand ik?

Try using a ChildOfConstraint, it would be easier to set and use than copy rotation constraint

As mentioned by Denis, a child-of constraint would be easier.  But it's still possible to answer your explicit question, "How can I set the empty rotation in such a way that the hand will have the correct resting rotation when I add the copy transform to the hand ik?"

Get the hand posed how you'd like, without the copy transforms constraint.

Give the empty a copy transforms constraint (world->world space) targeting the hand bone.

Apply visual transform on the empty (ctrl A menu in object mode for me) then delete its copy transforms constraint.  If necessary, register keyframes for the empty.

Now give the hand bone the copy transforms constraint targeting the empty.


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Smooth edge loops on sphere
I'm trying to model indented circles onto a sphere with clean topology. I think I have accomplished that, but I am struggling to maintain the smoothness of the sphere with the added edge loops. I can't remove these added ridges. I've tried to increase subsurf, subdivide, and manually add in edgeloops to even out the topology density, but this just exaggerated the effect. How can I maintain a smooth spherical look while still having a clean topology for these indents? I created the sphere by subdividing a cube several times, and then applying a subsurf.

You should try to avoid those extra edge loops. If your sphere has not enough vertices to allow you to create your holes then recreate a new sphere with more vertices, but it looks like you have enough. Also, before the hole extrusion, you can use a Shrinkwrap modifier with a second sphere as Object to make sure that the whole shape is still a sphere.

This looks like a job for the Cast modifier.
Add it to the end of your modifier stack, and set factor to 1.


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Geometry nodes, How to offset points on face along normal direction by random value?
Im trying to scatter Swords along of a giant monster and i had a rather good first time working with geometry nodes.
My question is: How do i offset the different points on my mesh that where generated by the "Distribute Points on Faces" Node along their normals by a random value each?
In this example i would like to have the swords be placed in different depths inside of the titan.

you can use this node setup:

to get this result:

Thank you very much Chris, this solved the problem. For anyone from the Future: I deleted the index node for a random displacement, as the index node somehow made the location offset unified.

You are welcome


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Making a cycloid in blender?
For a school project, I'm investigating the brachistochrone curve. As part of this, I want to make a 3D simulation of an object falling down a cycloid, but I'm not sure how I would actually go about making the cycloid?

Another way (though @MartyFotus has a more correct approach) is to use dynamic paint. With this, you can actually 'track' the point on the circle as it moves.

Somewhat related https://blender.stackexchange.com/questions/165190/how-to-do-trammel-of-archimedes-animation

You can enable the Add Mesh: Extra Objects add-on in your preferences.
This will allow you to add a Mesh -> Math Function -> X, Y, Z Surface.
You can then go to the Last Operation options panel and enter the necessary equations:

By playing with U min and U Max you can generate more or less of the cycloid.

If you want just the curve, then set Z to 0 rather than v.  Here's the curve for two  "humps"


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Connect mirrored object with a face
I'm trying to connect faces witch are mirrored and extruded to the middle. And when I try to fill it does not work

maybe you could delete the mirrored mesh and all these edges, then extrude the mesh, instead of trying to fill?

Thanks @moonboots that worked

Delete the mirrored mesh and all these edges, then extrude the mesh, instead of trying to fill.


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How do I keep materials when applying geometry nodes
I am fairly new to the Blender community and am struggling to achieve applying a geometry node set and keeping it's materials. I bought this modular building pack and am planning on expanding upon it by creating multiple new modules, but I need to "apply modifiers" in order to export so I can use these as assets in Unreal.
I think the issue is that the base mesh which is hosting the geometry nodes has one material, but I am hoping there is a way to keep all materials, as if I expand upon this file, there could potentially be hundreds.
Thanks in advanced!
b

Try to use 3.0.0 alpha. This problem has been fixed

Hi, thank you for your response. Unfortunately when I open this project in 3.0.0a it is missing modules, and when i go into the node editor to adjust the sliders, it immediately crashes. I don't know if this is a separate question or this could be addressed here. Thanks!


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Use blender particle system on terrain that has been displaced using displacement node. 2.8
I created a very substantial procedural system that creates everything procedurally. I went to add the rocks, grass, and leaves to the terrain using the particle system. But when I went to render, everything was beneath the terrain. I cannot use the displacement modifier, so do not suggest. I am using cycles on 2.8.


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Over coming a length restriction
I've been working on assets for a game and I've run into a bit of an issue. The game requires that all blender assets be below a specific x length. Changing the coding of the game is unfortunately not possible, would it be possible to overcome said restriction by manipulating the mesh in blender? Is it possible to make the mesh visible beyond said range without violating the restriction?

Hi Andres, could you provide more context and info on the restriction? May be describe the type of object or scene you're working with. Even better if you have some screenshot with examples of working and non working assets illustrating the length restriction. That would definitely increase the chance of getting an answer!

also this is more of a gamedev question since I dont think the solution will need some more blender knowledge


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Materials show up in material preview but not in render preview
I creating a project in cycles, but I am having trouble with the materials. The materials show up fine in the material preview, but when I switch to render preview, some materials turn pink. How do I fix this? Thanks in advance!
 material view  render view

Are you using an HDRI image texture for your lighting in a world shader?

Pink usually means that image texture path is lost (it requires re-linking). It might also be caused by wrong or missing Texture Coordinates mapping (material nodes)...


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How do I delete a shader node (From Script)?
I am writing an addon and I need to delete an image texture node from the active material. I know that the python for deleting the node from the editor is bpy.ops.node.delete(), but I don't know how to make this work from the script. I might sound dumb asking this, but I am a beginner to writing addons.
Thanks in advance!

Hi  @andesign , please check the checkmark left to lemon's answer if it helped you - and i think it did. Thanks.

You can do something like this:
import bpy

#Get the material you want (replace the name below)
mat = bpy.data.materials['Material']

#Get the node in its node tree (replace the name below)
node_to_delete =  mat.node_tree.nodes['Principled BSDF']

#Remove it
mat.node_tree.nodes.remove( node_to_delete )


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Automatically cut plane by alpha channel
I have a png logo I have imported using the import images as planes addon. This means that when I enter rendered view, the plane is transparent in the places where opacity is 0. Can I take this information and cut the plane by the alpha channel? I know I can do this same thing manually with the knife tool but I am wondering if there is a faster way to do it.
Thanks in advance!

https://blender.stackexchange.com/a/173458/92768

https://blender.stackexchange.com/questions/74332/carve-alpha-channel-from-plane?rq=1


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Why does my hair particles grow on the other side of the vertex grouped mesh?
I added hair particle system on my mesh using vertex groups but it seems it applies on the other side of the mesh rather than the area where I specified with vertex group.

As you can see it followed the vertex group but its on the other side of the mesh.
I'm aiming for a velcro type of hair particles on the vertex grouped area but I don't why the particles system is acting this way.
I'm using blender 3.0.0

Maybe try to flip the normals? Select all in Edit mode and Alt N > Flip Normals

Are you using a solidify modifier?

@mqbakamqbaka No I'm not using solidify modifier

@moonboots It worked!
Thank you, I didn't the normals were flipped.

Flip the normals: Select all in Edit mode and AltN > Flip Normals.


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Final render isn't showing composite background color
I'm following Blender Guru's donut tutorial and this is my first go at 3D rendering. I have a problem I can't seem to solve. I created a background color for my donut in compositing, and I can see it on the viewer that it looks great, but when I render it, the color does not show up. The background just shows nothing (checkered background).

Not sure, but try unchecking the Alpha checkbox on the Composite node

Make sure that in Output Properties > Post Processing > Pipeline the option Compositing is enabled. If that's the case but the Image Editor still shows only a transparent background as Render Result, make sure the layer selection is set to Composite and not View Layer.

By the way, if you have a render layer with transparent background, it's not necessary to plug the Alpha output into the Fac input of the Alpha Over node, it uses the transparency of the render layer naturally.
The Fac input can be used as a mix factor, so for example if you set it to 0.5 instead of 1, the image on top is semi-transparent where the original is opaque. Or if you have a different image or mask or whatever you want to use to control the mixing, you can plug it in there, too.
But note: whatever you plug in there is working as a mix factor, it's not replacing the original Alpha of the image.

That did the trick! Thanks!!


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How to add driver expression result from previous frame to current frames expression (way to compound expression output?)
I am new to blender and I cant seem to filter through all the resources to find an answer to my question.

How can I create a driver expression that adds the result from last frame to the result of this frame?
I have a very complex formula I have created but realized it is useless unless its result can be added to itself every new frame. Is there a way to accomplish this? I cant find a way to compound the answer each new frame.
As a simplified example, lets say the expression is var + 2. Lets say var = 1 and will never change just for this example. Each frame, the output will always be 2. If I could add the value of the last frame to the current frame, each frame the value would increase by 2 every new frame. Like a summation of the values it puts out each frame from all the frames before.
I hope I didn't over explain it!
I am hoping there is some sort of python expression or input variable I can add that is the result of the expression from the previous frame. I am brand new to learning python and I am no where near understanding how to accomplish this with a separate script.
Any help is greatly appreciated!

You can write a 'driver function' that could store the value from the previous frame and use that when calculating the value in the current frame. See https://blender.stackexchange.com/a/108484/29586 for an example that does similar to 'queue up' the location of an object to replay it back delayed by a number of frames to demonstrate what's possible. I don't have the time to write a full answer or locate a more appropriate answer for your specific problem (it's far more complicated than you'll need) but I hope that helps get you in the right direction.

A "vanilla" (restricted access) driver is stateless in a sense that each frame can be calculated independently. For your idea of a driver to work, it would have to access a value on a previous frame (and so jumping to the 100th frame would require calculating all 99 previous frames).
I might have stumbled in the past on a way to create a circular dependence (that Blender avoids, as normally it hangs the program), where I would get a feedback loop by feeding the output to the input. I think it was just constraints without drivers, tried now and couldn't get a feedback loop like that for drivers. Even if I did, controlling it would be hard - even if it updated only once per frame, changing a frame wouldn't read the value from a previous frame, but a value of a previously selected frame (e.g. when moving the slider backwards it would read the next frame).
There might be hacks using solutions that store iterative state like physics simulations or dynamic paint, but I don't think it's worth it to bother, so you need to use a Python script:
import bpy
from bpy import context as C, data as D

start_frame = 1  # when to start
end_frame = 250  # when to end
starting_value = 1
cache = {start_frame-1: starting_value}
formula = lambda x: x+0.01

def frame_change_pre(scene, depsgraph=None):
    frame = C.scene.frame_current
    if frame < start_frame:
        return
    if frame > end_frame:
        return

    cube = D.objects['Cube']

    cached_value = cache.get(frame)
    if cached_value is not None:
        # you don't need to do this if the calculation isn't CPU intensive
        cube.rotation_euler.z = cached_value
        return
    prev_value = cache.get(frame-1)

    if prev_value is None:
        return  # don't compute if a frame was skipped

    cache[frame] = formula(prev_value)
    cube.rotation_euler.z = cache[frame]

listeners = bpy.app.handlers.frame_change_pre
listeners.clear()  # remove old handlers before adding updated versions
listeners.append(frame_change_pre)
C.scene.frame_current = start_frame

I believe the #frame wildcard can be used in expressions like this. Maybe multiplying your formula by #frame will work?
The #frame wildcard simply returns the frame number. So on frame 1 it's 1, on frame 2 it's 2 and so on.


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How to animate a character made by two objects? (noob question)
I don't like bothering with my questions and I'm sure there's some tutorial about this there but since English is not my main language I'm not sure which words I should search to find it so I hope you'll be patient with me. I'm sorry.
So the thing is that I had made a character and this character had some kind of eyes in his face as an individual object. Just moment ago I was learning how to make an armature and animate him when I realised that, obviously, my character's eyes weren't moving as the rest of the body. Then in order to solve this I set parent to character's body but it didn't work.
So my question is: How can I merge two objets in order to animate them as a single character?
Thank you so much.

There is no need to parent your eyes to your body nor to join your objects. The only thing you have to do is to parent the eyes to their corresponding bones.
First select the eye objects, then the armature, then ⎈ CtrlP → Set parent to armature deform with empty groups.
Then with the eyes selected, switch to edit mode. For each eye, select its mesh, and in the Properties Editor → Mesh Data tab → Vertex Groups panel, select the bone weight you want to assign that eye to, and hit the Assign button.

in your second step, if you go to pose mode after the selection and pick a bone, you can parent the eye to a specific bone and not have to set up a vertex group for it.

It was easier than I thought. Thank you 2!


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With an accurate model of an ancient site, how can I import an accurate night sky star map (ex. 3300 BC, 12 midnight) to relate to its features?
I have an accurate Blender model of an ancient site that has features likely oriented to specific star patterns ( maybe sunrise as well ) around 3300 BC. I'm trying to import a night sky into Blender that can help test alignment of the model with the star patterns and be used to produce a video explaining the orientations. Ideally a rendering applied to the inside of a sphere, so the camera can be placed anywhere within the model to examine star alignments. The star map application would have to be accurate, can backdate and can paint the 3D interior accurately enough that angles to various stars from a fixed point in the model would be correct.
If Blender isn't the right tool for this, suggestions would be welcome.

Are you asking about how to put any star map into a Blender scene so to have it as the sky background, or are you asking how to get accurate star maps for specific dates?

It would be a combination of an accurate star map for a specific date, imported into a Blender scene so that a model of an ancient architecture can be aligned to it to show alignments of physical structures to the stars around 3300 BC.

What I'm asking is: are you looking for a star map or do you have no idea how to put it in the background of a Blender scene? Because only the latter is a suitable question for this site. Looking for star maps is offtopic since it has nothing to do with how to use Blender.


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Thin words without scaling
I have a multiple part piece it is a word that fits inside an outline of that word .  The problem is the letters are too tight to fit inside the outline.  If I scale it then it doesn't fit, i just want to reduce the outside of the letters without scaling it.  ie removing the tiniest percentage from the outline of the letter.  How can I do this?  Thank you.

Try the Offset Edges tool from the "Edit Mesh Tools" addon that comes with Blender, you just need to activate it. It will make crossing geo so there will be some clean up

You might try making the text regular size, then using the bevel option in the font datablock to fatten the outline.

The word you're looking for is "shrink", and Blender has the exact tool - "Shrink/Fatten" (Alt+S).

Note that this won't work on flat text, as it moves verts along the normals. For the same reason, make sure to only select the sides to avoid deforming it in the wrong direction.
Hold Alt or tick "Offset Even" above the viewport to ensure consistent thickness.


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I can't find "Node Viewer" in 3.3
I have the Node wrangler addon enabled, but when I use "shift + ctrl + left mouse", the  node viewer not appear, but connects in a straight line, but by pressing "shift + ctrl + right mouse" the node mix appears....
I have searched all the sites with the same problem, but no one has written any solutions that
(https://www.youtube.com/watch?v=DEgzuMmJtu8&t=8s) I tried to make a tree based on this video, but I need a node viewer there, do I need to install an old version of the blender for this thing??? wt

Node Viewer used to be just a simple Emission shader named "Node Viewer" by the Node Wrangler add-on. Since current version displays a texture plugged in straight to Output as emission, it is no longer needed. If you need an emission shader, you can find it in Add -> Shader menu:

You can change the name displayed on the top of any node by changing its label:


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I am not able to see the entire grid in object or edit mode in the view port?
I see a grey area in my view port but before I was able to see entire grid with axis? How to get back the original view port look? I am attaching a snapshot of the problem. I have used ctrl + alt+ Q just to show the problem from different angles

Hello and welcome. can you share your blend file https://blend-exchange.com

It looks like a Clipping problem, what does it give if you open the N panel > View > View and tweak the Clip Start and End values?

Thanks guys for trying to help. I just restarted my blender and it worked. It was weird!!

Thanks guys for trying to help. I just restarted my blender and it worked. It was weird!!


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Why pressing alt+1 for changing view axis works only in edit mode?
I don't have a numpad so I changed view axis to alt + number.

In my version of Blender nothing happens when using ALT + ordinary 1 key

@MarkusvonBroady Did you change the keymap for it to do something?

@GordonBrinkmann Vanilla Blender, Alt + 1 on Windows does nothing for me. By ordinary 1 key I mean NOT numpad key.

@MarkusvonBroady But you did read the title and the question, didn't you? ;) He changed the keymap from Numpad 1 to Alt + 1 because he has no numpad. Now Alt + 1 works like Numpad 1, but only in Edit Mode, not in Object Mode. The question he asks is: why doesn't it work in Object Mode, since the keymap can only be changed in general, not separately for both modes, and since Numpad 1 works in both, he assumed the changed Alt + 1 should do the same.

@GordonBrinkmann Hmmmmm.... I'm going to go with "He edited the question within the 5 minutes of posting it" :D That's definitely what happened!

@MarkusvonBroady lol definitely! :D

I only have one explanation, most likely Alt+1 is bound in some other way so that it cannot be used in Object Mode.
But I have to admit I checked for other key bindings of Alt+1 and changing them to something different (although they didn't seem to do anything when I tried) still didn't help making it work in Object Mode.
However, an indication that my suspicion is true: when I changed Numpad 1 to something completely different which I assumed to have no other function in Blender - in this case I used Shift+Ctrl+Alt+] or something like that - then it suddenly worked in Edit Mode and Object Mode.
So I guess you just have to find some other shortcut that suits you better and works in both modes.

Yeah, I changed it to just numbers and still it works only in edit mode. WEIRD :D

@ArtoMikaelMuukka Not weird. Just numbers have assignments in Object Mode, so I guess it's the same reason as for Alt+1. I'm afraid you might have to come up with something more odd or complex, as the simple shortcuts are most likely all occupied.


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how to change user preference in blender version 2.81
i just downloaded blender 2.81. I'm very new to blender. I'm using blender on a laptop and I know that some settings are different if you don't have a mouse (which I don't.) I've learnt online that you're supposed to change the user preferences. From what I've read, you should type %appdata% in the windows search box and find the app data file (which I did), and i did find the user preference window  (userpref.blend) thing. Problem is, I don't know how to change the user preference after I've gotten into the window. Can someone kindly tell me what I should do next? thanks!

The preferences can be edited within Blender. For 2.8x they are located in Edit > Preferences. More information can be found in the manual.

Note also that the settings to modify the input peripherals' behaviour are in "Navigation" and "Keymap" Tabs

thank you very much!

Since you're working on a laptop you likely want to enable the Emulate 3 Button Mouse option in the Input tab, which allows you to rotate the 3D View through Alt+RMB. Please be aware that this changes the shortcuts for other commands that use the Alt key, for instance the edge loop selection.

@bug if this answer solved your problem, please consider accepting it by clicking on the checkmark.


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Merge Grid Lines into single Mesh
I created this grid for use in a game. Users will use the grid as a guide to add road.
I created the mesh by drawing a rectangular plane and performing several arrays. Then I applied the "wireframe" modifier to create lines.
I now want to merge all the lines/planes together to create single mesh. How is this possible?
Ideally, I'm trying to reduce file size as I just need the lines visible.

Does this answer your question? Merge multiple meshes into one single mesh?

Could just go Add > Mesh > Grid .. Wire Frame modifier... apply if you want...


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Grease Pencil Render border missing
When I started drawing/ animating each frame there was a border that showed where the rendered view would end. Recently it disappeared and I am wondering how to get it back.

I think you are talking about the camera view - Numpad 0  (if you have a camera)


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Dotted lines and crosshairs in imported .dae
I'm pretty new to blender, so it might be a stupid question but I can't find a solution/explanation for this online.
I imported a character file from a game into blender, in the .dae format, since the original file was a animation before I converted into .dae, I would assume it came with the first frame pose, anyways... there are this dotted lines and crosshairs around the whole model, I would assume that they are the bones (because they are conveniently placed where the bones should be), and I should be able to change the character pose using them, but I can't find a way to move them with the model, it only moves the crossair that I clicked. What do I need to do?

Relationship lines https://blender.stackexchange.com/questions/33242/what-are-these-block-dotted-lines and empties (at joint locations) rather than bones.  IIRC there could be an option between armature (bones) and empties in importer.

@batFINGER How do you do that?

@RayMairlot Yes, but why are they there if they're not moving the model?


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Joining faces in a model
I recently started dabbling into 3d printing. I extracted a model from a old game, but I noticed that the faces of the model are not 'glued' to each other, they are basically standalone faces near other faces to make the model, how can I make the model a solid or how to join 2 faces to do it to the whole model manually?

Select all vertices, right click and then select merge, merge by distance, which should do just as you want.

Hope this helped!

I'll try that! Thank you!


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Manifold problems
I am doing a model to 3d print, I finished it, but when I put it on the slicing program, the model shows all sorts of bugs.
After a search, I found that this is a Manifold problem, and then I made my way into the 3d Print Toolbox in Blender, but after I click the "Make Manifold" in the Clean Up section, almost the entire model disappears.
How can I fix it?
Heres the model:
https://mega.nz/file/ps5VVY7a#hE5nJfmL2FNVv0XUvkA4b8wY9mN78vFlhAtcA7HVnjY

Select your object. Go into Edit Mode. Select everything. Press P and choose By Loose Parts.
You will see that your model is made up of five separate meshes, and that would be problematic to print.
Two of these meshes seem to be floating around and not part of anything; it seems safe to delete them.
The other two are cubes in the dashboard area. If you need them, i think you need to manually make them part of the main mesh by deleting geometry around the cubes and connect the cubes to the rest using F. You'll want to be careful not to create non-manifold geometry while doing this. For example, when you are done each cube should have 5 faces, and not 6 where one face is hidden on the inside.
This might also help:
What is non-manifold geometry?
I'm not sure but I suspect you might run into more problems trying to print this model, but i guess you can start by solving this issue. In any case, good luck.
EDIT:
As I suspected your model had a lot of issues that needed to be resolved before it can be 3D printed. I've looked a bit closer and for instance, next to the gear stick there are a lot of faces sticking into the floor. It makes me wonder how this model was created, and if it were possible to resolve these issues at that first step.
In any case, Select Non Manifold might help if you want to visualize and learn about the issues of this model, or any other model for that mater.

Thanks, I'll try that!

Yeah... I can't fix it

I was afraid of that. That's to bad. I edited my answer; hope it helps a little bit.

I found my way into that option yesterday, but I have no Idea how to proceed from there.

I think the model has a lot of problems, and i think it will take a lot of time and some skill to solve them all. If i had this problem i would look into getting a better model to begin with. And if that wasn't an option, i would (because i have some 3D drawing experience) re-draw it from scratch sacrificing a lot of detail, and maybe copy and integrate some parts into the new model. I'm afraid there isn't an easy fix for this model as it is now. In any case, if you do any further work on this project, i wish you good luck with it.


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Mesh hair does not properly follow head

Hello, this is a problem I have had since I've started using Blender (2.82). The model was imported from Makehuman. If I use hair from Makehuman, no problems. If I create a hair mesh, it never follows the head properly. I have tried every form of parenting. Messed around with weight paints, constraints and vertex groups. Watched tons of tutorials, read dozens of posts and "Blender for Dummies". Nothing works. (the braid doesn't follow the braid bones properly either.)
I have created several different meshes with different Makehuman rig types but the result was always the same. It shouldn't be this difficult to do something so basic as sticking hair on a head. I can't help thinking that I'm missing something obvious but I don't know what it is. I would have uploaded the file but I didn't see where to do that. Any help would be appreciated. Thank you.

I have since discovered a two step method that seems to work. (Whether it's the best method is another matter.) I parent the hair mesh to the armature with empty groups. Select the model mesh, then shift select the hair mesh. Go into weight paint mode and transfer weights, selection: by name. Wa-La. It works, but then the hair mesh picks up all of the model's vertex groups.

and you'll find that in most of these groups the weight of all vertices is zero (e.g., feet and lower extremities).  One could write a python script to find and delete these... alas there's no built-in command to clean this up.


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Blender 2.8 dosen't recognizing my graphics card
I have GeForce GT610. I saw the settings of Nvdia control panel and add Blender for CUDA support but Blender 2.8 is not recognized my graphics card.

The essence of the link mentioned by @RobertGützkow is that the Geforce GT610 mentioned, based on the list here: CUDA version has CUDA 2.1 compute compatibility. So sadly not the needed 3.0+ for Blenders CUDA functionality.

But you can still use blender 2.7x or 2.6x and do a lot of things...

Cycles in Blender 2.8x requires a CUDA compute capability of 3.0 or higher. The Nvidia GeForce GT 610 has a CUDA compute capability of 2.1 which is below the minimum requirements for GPU rendering. This is documented in Blender's manual.

CUDA
CUDA requires graphics cards with compute capability 3.0 and higher. To make sure your GPU is supported, see the list of Nvidia graphics cards with the compute capabilities and supported graphics cards. CUDA GPU rendering is supported on Windows, macOS, and Linux.


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Adding given number of objects to an area using Python
I have an area (the large cylinder) where I want to be able to quickly add a varying amount of small cylinders to. Is there a way in Python I can do this by giving the dimensions of the cylinder and then the number of them across the space?

Would you consider using paricles?

I am a blender beginner so open to all suggestions!

Do you have advice for using particles?

Coming up .. unless someone else answers that way before me.

The devil might be in the detail.. but here's a base case of using a Particle System to scatter objects on a given area.

Create / Duplicate a face representing the area you want scattered with the objects
Create the object you want to be scattered.
In its Particle Settings tab, set the face to be a particle emitter.

There are lots of settings for particle emission, but most of them are self-explanatory, maybe after a bit of trial and error. Here are my settings for this example, trying to keep everything simple to begin with, everything else at default:

All the particles are emitted on frame 1, and have a lifetime of 1, so you have to be there on the timeline to see them.

This is the rotation setting that works for me, with my scattered object ('Cylinder') created with its local Z along its length.
Depending on what you want, at any stage, the particles can be made into real instances of the scattered object by hitting Convert in the emitter's Particle Settings modifier (in its modifier stack)
Be aware that if you copy the emitter, it will share the particle system with the original. As with other kinds of shared Data-Blocks in Blender, you can make it unique to the user by clicking the digit indicating the number of users under the list of Particle Settings at the top of its Particle Settings tab


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Removing internal mesh to make object hollow
I followed steps to make an ellipse with multiple regular holes using cylinders (picture on left). How do I remove the internal cylinders from the ellipse (picture on right)?
I ideally want to end up with the ellipse hollow with a 1cm lining
.

If you model the cylinders as a separate object, you can use a boolean modifier on the sphere/ellipse to 'subtract' the cylinders. Then, if you turn off the cylinders (you don't have to delete them), you'll have the sphere/ellipse with holes where the cylinders should be.

I don't know any better way to do it than the following (and I assume this is all one object, with all the vertices merged. If not, there's a simpler option):
Go into Edit Mode for the egg-shaped object and also activate Face Select mode. Alt + select any face of any cylinder where it meets the egg's outer shell. This will select all faces in that cylinder, or at least, all of the faces which would make up a face loop that is  nearest the shell. Now delete them (x, then from the Delete Menu, Faces). If any part of the cylinder remains, leave it. The important thing is that it's no longer directly touching the egg object.
Now repeat the above steps for the next cylinder (Alt + select the face loop which meets the outer shell, and delete that part which meets the shell). Continue until the outer-most face loops for all cylinders is deleted.
If your topology was such that the above process got rid of all inner parts, you're done. If not, continue below.
While still in Edit Mode, press p and from the Separate menu, choose Loose Parts.
Now go into Object Mode, select some part of the inner structure which remained after the previous steps (if you did everything right, it should select the interior as one whole piece. If it won't select, examine the mesh for signs of incomplete or botched separations), and delete it.
When this is all done, go into Object Mode and click on the Modifier tab of the Properties Panel. Choose to create a Solidify modifier on the egg shell object. Choose a thickness that suits you.


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Joining two cylinder at 45 degree angle
I'm trying to join these two cylinders together. I tried the pipe joint mesh but the diameter will not go small enough.
Equally, is there is a way to extrude the face of the top cylinder vertically downwards at an angle but that the face is level?
I am new to Blender so realise this seems very simple but any help would be appreciated!

you can activate the LoopTools addon if it's not already the case, then select the two edges and right click > LoopTools > Bridge

Or, Bridge Edge Loops, and its options?

yes, but it looks like it is not available in Vertex Selection mode (in my 2.8 version at least)? Not sure why...

thank you for all the advice!

it's not clear if you want a round transition between your 2 cylinders or you want to keep a sharp angle?

@moonboots  even from Vertex Mode, I just need to call up the ol'-fashioned Ctrl-E edge menu, in my 2.83 release.. I'm still missing a lot of the old standard shortcuts.. :)

oh ok so it's not just me  ;)

To make a pipe bend the quickest way is to use the Bridge tool: Select both the 2 rims vertices and right click (context menu) > LoopTools > Bridge (you may need to activate the LoopTools addon before), or in Edge Select mode, CtrlE > Bridge Edge Loops. Then in the Operator box, set the bend as you want.

If you want to create a pipe bend but want to keep a sharp edge, the new (2.8) Mirror modifier allows you to do it easily: Create your cylinder, create an empty, give your cylinder a Mirror modifier with the empty as Mirror Object, choose (in my case) Axis > X, Bisect > X, Flip > X, move and rotate the empty until the cylinder and its mirrored merge the way you want (keep pressing Ctrl during the rotation if you want it to be 10° by 10°).

The Shear tool also allows you to create sharp bends but it's not convenient if you want precise angles or if your object is not perpendicular to the axis.

Ah, thank you! Was the look I was hoping for!

Select the top loop of vertices on the bottom section and the bottom loop on the. Upper section,
Press F3 and type bridge edge loops and play with the offset.
Read How to bend a tube with consistent thickness?
Or enable the Mesh extra objects add-on.
Then you can create the object directly by adding add pipe joints and choose the shape kind. Of pipes you need

How to aproach the modeling of duct work, piping, wiring?

Yes, I tried this at first but then realised it has a minimum radius of 1cm and my design is smaller than that. But the bridge edge loops worked so all fixed!


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Creating new vertices where meshes join
When I join the the meshes, is there a way to create a new seam along where they join, to then remove the internal geometry and get an accurate volume estimation for the new mesh?
It's the diamond shape and the smaller cylinder. I can see a trace of where the two intersect but there doesn't seem to be an actual join as when I remove the lower vertices of the cylinder in the diamond after joining it removes the edges all the way up to the higher vertices.

Hope this is clear!

Hello :). You need to physically join the meshes (using Boolean or similar tool). So far, you only 'grouped' your meshes into one object.

Oh thank you! So simple, I knew there must have been an easy way to do this, google kept pointing me to complex solutions.


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GLTF animations distorted after export
When I export my character from Blender to GLTF and view the result in the GLTF viewer, the character looks distorted:

However, this only happens if the animation is not selected in the Action editor when I export. If the animation is selected, then the character looks normal:

This affects all animations in the GLTF file - only the animation that is currently selected in Blender when I do the export looks correct. Note that I tried several different GLTF viewers, so it’s not a problem with the viewer.
I thought perhaps the problem might be that some bones were not getting initialized in the animation, but that is not the case - every bone is keyframed at frame 0 with location, rotation and scale.

Suggest reporting a bug: https://github.com/KhronosGroup/glTF-Blender-IO/issues.

Yes, it's a bug. I've been working with the maintainer to resolve it. https://github.com/KhronosGroup/glTF-Blender-IO/issues/1539


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Is it possible to link values across multiple geometry nodes modifiers applied to the same object?
I have an object with multiple geometry nodes modifiers, each one with a separate node tree. I would like to have some of the input values to be always the same in all of them, as if they were linked, so I don't have to manually update each one of them after I change some of these values.
What I tried:

Controlling the values with an object info node with a controller object as input: it works but a separate controller object is needed for each one of my objects, and it would be too complex for what I'm trying to create.

Controlling the values with attributes: the attributes are automatically updated across all the node trees but I need the valued to be simple floats, so they can be used for example as info for a grid node.

I know an easy solution for this would be to have a single geometry nodes modifier with all the separate nodetrees inside so they share the same inputs, in fact it's the setup I'm using right now, but having the nodetrees in separate modifiers would help me organize things better for what I'm trying to achieve.

Let's make an example. So if you are using setup something like this, there Fac value drives amount of green cubes:

And you want to have Fac value to be the same across modifiers:

In this case, you should use drivers. Click RMB on one value, and select "Copy as new Driver" from context menu. Then Click RMB on other values and select "Paste Driver". Now value from first value will be transferred to the second.

Hey sorry for being late to the party, but I'm very interested in knowing how you set up a node system where a Fac input controls the amount of green cubes vs. purple cubes.  In particular I'm trying to figure that out right now.  Would you mind pointing me in the right direction?