text:
Particles do not render
I'm emitting grass (2 meshes into a Collection) on a mesh. Everything works fine in the EEVEE realtime preview but those particles are not visible/rendered in the final EEVEE render.
I'm using Blender 2.91.2
2 pictures : First one is the Preview, second one is the render.

Blend file : https://drive.google.com/file/d/1Vcl6Lz52V2MnKmsSOT3L_kBaE1icoxaG/view?usp=sharing

Can you also add screenshots of it

hello please share your file (at least the part that is emitting particles with its particle object): https://pasteall.org/blend/

Hello @moonboots, Link to Blend file added.

you need to reactivate the visibility of your grass object in the Outliner, I don't know if there's a way to hide the original objects though

I don't think the problem is the visibility of of my objects, in the following test scene, everything works fine with visibility deactivated : https://drive.google.com/file/d/14DdgTWquVcIuF87bxLyRouk2XxVGpABm/view?usp=sharing.  Am I wrong ?

yes but if you put it into a collection, and deactivate the cube visibility in this collection, the cube won't be visible either

I'm not sure it's the way it's supposed to work though, it may need a report

Thanks for your help.


text:
Capturing Spline Factor Attribute for Linear Interpolation on Geometry

I am attempting to perform linear interpolation using the spline factor, transitioning from yellow altitude to green altitude. However, when I try to capture the factor attribute, I consistently receive a value of 0 for my mix factor. Can anyone provide guidance on how to successfully achieve this interpolation? Your assistance is greatly appreciated. Thanks in advance.

if you exchange min + max and use a sample nearest/index node like this, you get this:

Hope that helps.

source: Stack Exchange

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

sort: votes


text:
Need some guidance on creating this photon torpedo
Need some help to make a photon torpedo from Star Trek, as the one attached.
I know how to make the sphere object titillate and change colors.
I tried doing an emitter and attaching picture to make the beams but it looked choppy.
How can I make and make and animate the "beams" that surround the torpedo?

You can always use compositing. Getting the torpedo on its own layer with any occluders as masks shouldn’t be too hard. You can use a glare node to get some beams probably, and with some animation for frame number usage, it could work.

seems more a work for a post-prod soft like After Effects

Is this for Eevee or Cycles?

@Blunder I am open to doing it in either. Whichever gets the best look. I realize there is some compositing work, I am just not sure how to go about it. Especially with the beams/rays.

The beam effect of the "photon torpedo" (or "magic missile"/"wisp") can be created on the base of a fake light cone, that is turned into a "billboard" which always points to the camera. A Displacement modifier animates the beams.
Example animation (Cycles, 10 samples):

Known issues:

In Eevee, it works in a dark environment when you set Settings > Blend Mode to Alpha Blend on the Material Properties tab. Depending on the shader for the halo effect and in a bright environment/room try Alpha Hashed. But this will cause a lot of noise in Eevee. Probably because Eevee can't handle transparent emissions not very well. Increasing the sample count to 256 and the Denoise node in Compositor helps a bit.
the photon does not work well as a particle instance (rendered as a whole collection) because all Displacement modifiers use the same Empty. So the beams look all the same for a given frame. To randomize this more a Geometry Nodes modifier might be a good choice (not tested).

The photon model is a half-sphere with "a tail" of 2 cones. Select the bottom vertices of the inner cone and outer cone and add each group to a vertex group (Displaced in the example). Use this group for the Displacement modifiers. The built-in Clouds texture was used for the modifiers. The Displacement modifier of the outer cone has a very low Strength (0.1). The inner cone has a high Strength value (2.8, see screenshot).
A moving Empty object generates the noise/animation for the modifiers.

Make both cones a child of the photon sphere. Then add a Damp Track object constraint to it and select the camera as the Target. Try -Z or Z for the Track Axis to make it always point to the camera. Depending on the size of the halo effect, it may look better one way or another.

The inner cone has a Subdivision Surface modifier to smooth the result of the displacement. (The Solidify modifier was just a test.)
Shader (Cone Inner, Beams):

Shader (Cone Outer, Halo):

Shader (Photon, center):

I feel like I am almost there, however, I think I am missing a detail/step on how to get the right position of the materials. I uploaded a screenshot of what I have.

I can upload an example if you want to have a look. I've tested a Geometry Nodes modifier as a replacement for the Displacement modifier. It works partly. You can have unique torpedos but the Damp Track constraint is messed up. Maybe the torpedos need to be fired with GN, too.

Id greatly appreciate it if you could! Or if it is possible here to upload the blend file, I would look to take a look at it and compare/learn.

Do you think I could get that torpedo model but in orange like normal ones. I'm making a game it would be helpful. Thanks discord is iroge #0502

Oh sorry, I forgot to upload the blend file :-/ I think I still have it somewhere and can add it...

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


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Creating a Single Image Texture Bake From A Complex Object - Broken Textures Result in 2.9
I'm very very hilariously new to Blender but am trying to suss out a specific project.  I have a complex object created from several different objects, each of which has its own texture image, each texture image made up of 3-5 layered textures, that I want to combine into a single texture image so I can import it into Tabletop Simulator.
I've spent several days stumbling from tutorial to tutorial to tutorial but I cannot for the life of me figure out what I'm doing wrong.
This is the model with the final surface texture I want to bake:

This is the tutorial I've had the most success with:
Blender 2.8 Bake multiple textures into one
Here's my bake result:

Which looks broken in my shading tab.

Yet somehow even worse in TTS.

I've tried baking just the Diffuse, as well as changing the Max Ray Distance from 0 to .5, and this is the best result I've gotten yet.  What am I doing wrong?

How does it look in rendered view before baking?

I don't know, none of the tutorials ever mentioned that

Rendering image via f12 results in a blank image

Am I supposed to be rendering first?

No, you don't have to render first, but it can be a good way to check for problems. You can check in the viewport by clicking the rightmost sphere in the upper right of the 3D view. Also, there is a lot of magenta which is usually caused by a missing texture.

have you tried checking face's normals? if they are inverted, on TTS they might not appear correctly. It is usually an easy fix.

Hi, thanks for the post. This site is not a regular forum, answers should be substantial and thoroughly explain the solution and required workflow. One liners and short tips rarely make for a good answer. If you can [edit] your post and provide some more details about the procedure and why it works feel free to restore it, otherwise it may be deleted or converted into a comment. Perhaps add a few images illustrating the workflow and final results. See How do I write a good answer?


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Why is Cycles causing this distortion in displacement of a cco node?
This is a very simple two object seen.  I'm using CCO textures setup per there instruction.
In eevee, it looks normal.  In cycles it looks normal in preview view, but in rendered view it looks distorted.  This happens in both 2.8 and 2.9.  The only thing that seam to fix it is detaching the displacement node.  It only seams to happen with this seen, or at least it hasn't been so bad as to engulf the other objects.
Thanks for the help. I think I did what you suggested. Even if I didn't it still looks better. I think. If nothing else I now know what to play with.

One solution is like you said to disconnect te dislacement node. The other better solution is that you mix your displacement node with your normal map. Add a bump node and set the distance to somewhere around 0.01. Once that is done, connect your displacement image texture (Without the displacement node in between) to the height input of the bump node. Connect the normal map with the normal input in the bump node and connect the bump node to the normal input in the Principled BSDF. The way you did it heavily displaces the whole mesh.
Extras: You can try to decrease the scale of the displacement map the way you connected to about 0.001 or something as an experiment.


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Cell Fracture Add-On Automatically Decimates Base Mesh
Wondering if anyone here can offer some advice on the Cell Fracture add-on.
I am trying to fracture some very high-poly triangulated 3D scans but it seems that the Cell Fracture add-on takes it upon itself to simplify the base mesh on it's own and the resulting fractured objects are very low res.
I looked into this and I see that about 2 years ago, the bundled Cell Fracture add-on had a lot more options than what are available now in 2.91. Specially, it appears that there was once a 'Simplify Base Mesh' option in the Cell Fracture setup (along with numerous other options) but they are no longer present in the add-on.
Even though it would appear that the 'Simplify Base Mesh" option has been removed, is it plausible that the add-on is applying this feature during the fracture process?
I would like to avoid Cell Fracture from simplifying my mesh.  I am also curious about why the current version of Cell Fracture has fewer options available than it appears to have in previous versions.
Example:
My original mesh before fracturing:

The result. A decimated/simplified low-poly mesh:

Current Cell Fracture options (v 2.91):

Previous Cell Fracture options (v 2.8 - notice the 'simplify base mesh option, and others):

(as seen in this youtube vid: https://www.youtube.com/watch?v=5guh5naT-XM)
Any advice would be greatly appreciated!
Thanks

Sorry for the late reply, but I have been running into this problem as well and managed to find a solution. I have a pretty high poly vase model I wanted fracture:

I run into the same problem you did, where the Cell Fracture add-on was decimating my model. It took me a while to figure out what was going on.

The answer to the problem lies in the settings menu for the add-on. I found it while fiddling around with the add-on and trying everything to try and fix the issue. Note that this is the newest version, and there is no checkmark that disables model simplification. However, by checking "Debug-Boolean", the add-on, for some reason, will not simply your model. The other settings did not matter and you can still adjust them to your preference.

As you can see, there is a nicely fractured vase that is free of decimating. The debug option does come with the drawback that you have to apply the Boolean modifier on each generated piece if you want to manipulate them, as high geometry boolean interactions are very slow.
I don't know if the debug option was intended to disable simplifying, but it does, and it works. I don't understand why they removed the disable simplifying option from the newest build, but I hope it can be added back. Anyways, best of luck on your work!

Thanks for looking into this. You arrived at the exact same solution as I did.  I should have come back to edit this thread sooner.  Your method of using the debug boolean seems to solve the issue and you're correct, it's quite a pain as each modifier has to be manually applied.  It's certainly a good enough work around for now.  I hope that they will take a look at this in a future update.


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Let reflections and shadows continue over edges
I've been trying to get this to work for a few days, but I can't seem to find out how. I want to have an object with two colours (materials) reflect light seamlessly. These objects are generated procedurally, so manually integrating these colour changes in the uv map is not a solution (there are about 4000 repetitions).
Blender does the following:

Expected normal behaviour: entire step reflects light

Unwanted behaviour: the light and shadow breaks at the edges

What it looks like without added edges

What it looks like with the added edges
How can I force the light to be reflected normally across the edges?
Edit:
PGmath suggested recalculating normals and auto smoothing. Recalculating normals had no effect, auto smoothing has the following effect:

The material looks completely matte now
I have tried using ALT+N > Merge with auto-smooth, which has a better result, but still not as desired:

It looks like you have some smooth shading artifacts, try turning on auto smooth.  Its hard to tell but you may also have some inverted normals on you model so I would also try recalculating the normals (Ctrl+N).

Thanks for you comment PGmath, I have updated the post with new images

have you tried using generated projection for the image?

My guess is that the result is "correct" once you applied auto smooth.  Smooth shading bends the normals on flat faces to make them appear curved, so now that the faces are correctly reflecting glossy rays as a flat surface, they look matte because there isn't enough in the environment to make nice looking glossy reflections.  If you plan to fill in the rest of the scene and make this indoors I suggest doing that first, otherwise you can use an HDR panoramic environment texture to make some nice looking reflections.

I think you may be right, PGmath, when I place the first stairs (that I thought looked right) in an HDR environment, it has really odd reflections, the one with your adjustments has proper reflections. It still has some odd stuff going on around the corners, but maybe I can live with that.


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Blender 2.91.2 Mantaflow fire + smoke simulation doesnt fully render in Eeevee (very little smoke and no fire at all) vs in solid object
I tried cleaning cache and changing its location to somewhere else, tried modular and all baking, still same result.
I tried changing to cycles but same result.
If needed, I am using AMD R9 380 4GB.
View in solid object.

Rendered image.

My domain settings.

My domain material shading.

SOLVED USING 2.93 ALPHA (RESULT):

You cannot use a Principled BSDF shader for the volume, it's a surface shader. You should use the Principled Volume shader. That's the quick explanation. Creating fire is a wide field, but to manage the first steps I would really suggest you watch any tutorial on how to create fire with Mantaflow, at least one because it looks like you need to first learn the basics. Not meaning to be rude, but fire is such a complex thing.

Yes, I removed the surface node now and only connected it to volume, the screenshot is the wrong one, sorry.

Could you please replace the incorrect screenshot with one of how it is currently configured?  It does look like you have not configured the volume shader properly.

Updated! This should be correct. Both flow and domain used the same shading.

Problem solved! Seems like it's the problem with 2.91.2 itself. Tested using 2.93 Alpha and it works well. Had to change blackbody intensity in shading editor of the domain and everything works well so far. Updated pictures in post.


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How to get an Operator update (not re-create) an object/mesh when changing parameters
I'm having a problem updating a mesh after initial creation. I like to create a mesh in one step and update it's vertices afterwards, without completely recreating the mesh.
After several iterations I trimmed the code down to a minimum (below) and it doesn't seem to work...
I'm setting a custom property ("update") to the active object and print "create", if the "update" property exists I print "update". The code does not seem to take the update-branch and the property does not seem to be set. If I de-select the object and execute the Operator again, the property is set.
What am I missing? Do I need to update the object? Is there another way of doing this?
def execute(self, context):

        print(context.active_object.data.keys())

        currentObject = context.active_object

        if ('mesh_update' in currentObject.data.keys()):
            print("update")
        else:
            currentObject.data["update"] = True
            print("create")

        return {'FINISHED'}

Additional information
The operator is called from "add object" menu (the one using shift + a).
I also tried an operator property, a group property for objects in general and some other possibilities for days now.
The operator property does not work because this setting has to be object (or mesh?) specific and this setting would be carried to the next object the operator gets applied to. Pre defined object properties have the same effect as the dynamic one in the example code above.
Update #1
I handled my problem in a different way now by using a local variable inside the operator to switch between the "create" and "update" stages. This eliminates some other issues and is easier to work with. I had my code working this way some iterations ago while searching for a solution.
This leads to maybe the base problem I am trying so solve here: my active object changes between those stages! I explicitly set my newly created object to be the active one but as soon as hitting FINISHED and the operator's execute method starting over again (with the new stage "update"!) the active object changes.
updateMesh = False

def execute(self, context):
        use_enter_edit_mode = context.preferences.edit.use_enter_edit_mode
        context.preferences.edit.use_enter_edit_mode = False

        if context.mode == "EDIT_MESH":
            bpy.ops.object.mode_set(mode='OBJECT')

        currentObject = context.active_object
        # THE "OLD"/INITIALLY ACTIVE OBJECT IS PRINTED HERE ON THE VERY FIRST RUN
        print(currentObject)

        if self.updateMesh == True:
            # ERROR
            # THE "OLD"/INITIALLY ACTIVE OBJECT IS PRINTED HERE
            # NOT THE NEW ONE FROM BELOW
            print("update " + currentObject.name)
        else:
            self.updateMesh = True
            # A NEW OBJECT IS CREATED HERE, LINKED TO VIEW LAYER
            # AND SET AS ACTIVE VIEW LAYER OBJECT
            # OUTPUTS THE NEW OBJECT
            print("create " + currentObject.name)

        if use_enter_edit_mode:
            bpy.ops.object.mode_set(mode = 'EDIT')
        # restore pre operator state
        context.preferences.edit.use_enter_edit_mode = use_enter_edit_mode

        return {'FINISHED'}

Update #2
Here is a complete working example. Setup is like this:

execute the script below
Window > Toggle System Console
create an object (Monkey/Suzanne for example)
while object selected press SHIFT + A
select Mesh > Object Update Test (car icon...)
edit parameter (Dummy Property)

What it does:

Suzanne is the active object
an object "NewObject" is created and set active
changing the property "Dummy Property" removes "NewObject" and sets Suzanne active again

What it SHOULD do:

keep the object and show "update NewObject" when changing the property

import bpy
import bmesh

from bpy.utils import ( register_class, unregister_class )
from bpy.props import ( BoolProperty, FloatProperty )
from bpy.types import Operator
from mathutils import Vector

class ObjectUpdateOperator(Operator):
    bl_idname = "mesh.objectupdatetest"
    bl_label = "Object Update Test"
    bl_options = {'REGISTER', 'UNDO'} #, 'PRESET'}

    dummyProp : FloatProperty(
        name = "Dummy Property",
        default = 0.2,
        min = 0.0001,
        max = 10000.0,
        precision = 4,
        step = 4,
        )

    def draw(self, context):
        layout = self.layout
        box = layout.box()
        box.label(text="Basic Parameters")
        box.prop(self, 'dummyProp')

    @classmethod
    def poll(cls, context):
        return context.scene is not None

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

    updateMesh = False

    def execute(self, context):
        use_enter_edit_mode = context.preferences.edit.use_enter_edit_mode
        context.preferences.edit.use_enter_edit_mode = False

        if context.mode == "EDIT_MESH":
            bpy.ops.object.mode_set(mode='OBJECT')

        currentObject = context.active_object

        # problematic part...
        if self.updateMesh == True: # update object/mesh
            print("update " + currentObject.name)

        else: # create object/mesh
            print("create")
            print("active object: " + currentObject.name)
            new_mesh = bpy.data.meshes.new("NewMesh")
            new_verts = [
                Vector((-1, 1, 0)),
                Vector((1, 1, 0)),
                Vector((1, -1, 0)),
                Vector((-1, -1, 0)),
            ]

            new_faces = [[0, 1, 2, 3]]
            new_mesh.from_pydata(new_verts, [], new_faces)
            new_object = bpy.data.objects.new(name="NewObject", object_data=new_mesh)
            view_layer = context.view_layer
            view_layer.active_layer_collection.collection.objects.link(new_object)
            view_layer.objects.active = None
            new_object.select_set(True)
            view_layer.objects.active = new_object
            print("NEW active object: " + context.active_object.name)
            self.updateMesh = True

        if use_enter_edit_mode:
            bpy.ops.object.mode_set(mode = 'EDIT')
        # restore pre operator state
        context.preferences.edit.use_enter_edit_mode = use_enter_edit_mode

        return {'FINISHED'}

def menu_item(self, context):
    # we need at minimum one object selected!
    if len(context.selected_objects) == 0:
        return

    layout = self.layout
    layout.operator("mesh.objectupdatetest", text="Object Update Test", icon="AUTO")

# register and unregister
classes = (
    ObjectUpdateOperator,
)

def register():
    for cls in classes:
        register_class(cls)
    # add menu to shift-a add object menu
    bpy.types.VIEW3D_MT_mesh_add.append(menu_item)

def unregister():
    for cls in reversed(classes):
        unregister_class(cls)
    # remove menu item
    bpy.types.VIEW3D_MT_mesh_add.remove(menu_item)

if __name__ == "__main__":
    register()
```

A parametric approach is good ol' chestnut. Once a primitive is created only the name is an indicator of origins. (if not changed as well)  Possible dupe https://blender.stackexchange.com/questions/101141/parametric-primitives-through-python-script ??

Thanks for looking into this. I think the problem is more fundamental. Something seems to block the properties from updating if I set them by code.
If I set a property of an object it even shows up correctly inside the "Item" panel under "Properties" but if I try to access this property it seems like it has not been set!
If I deselect the object and run the code/operator again the property gets recognized.

IMO issue commented is  same as here https://blender.stackexchange.com/questions/181649/replicate-value-stored-in-object-into-properties-of-new-one  The execute is undoing redoing as settings are changing.

Thank you, batFINGER, for those suggestions. Maybe I only don't understand what is done in those posts but I didn't get my problem fixed.

@batFINGER I've updated me description and code above. Please see the code comments.

@batFINGER I've added a working example to copy&paste in combination with a detailed description. There must be something I don't understand about how blender is handling things...

I have absolutely no clue what I am missing... either it is a bug in Blender or I don't understand the whole mechanism of Blender (and python?).

No it's not a bug in blender it's how blender operators work.. As a little test hit G and move the cube, in rotation properties change a setting, then in the Move operators  redo panel change an operator property, the rotation will be reverted to what it was. ie the state when blender was invoked.  IMO you are going to go around in a circle trying to change this behaviour.

Ok, thanks for clarification. So there is no workaround for this?

I did some more research to find a solution to my initial problem. Could either "shape keys" or "drivers" change the mesh (vertices) after creating in an "update branch" of the operator? Or maybe even changing the operator of the created object?


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Script to Insert Keyframe for Fluid "effector_settings.use_effector" property
I have added a cube as an Effector to a fluid sim. I want to use a script to insert a keyframe for the 'Use Effector' property (see image)
Here is what i've got so far:
ob = bpy.context.active_object
ob.modifiers['Fluid'].keyframe_insert(data_path="effector_settings.use_effector",frame=1)

problem is that an error is thrown.
Traceback (most recent call last):
  File "C:\Program Files\Blender Foundation\Blender 2.91\2.91\python\lib\code.py", line 90, in runcode
    exec(code, self.locals)
  File "<blender_console>", line 1, in <module>
TypeError: bpy_struct.keyframe_insert() property "effector_settings.use_effector" not found

I will iterate over all selected objects once I have this piece sorted.
Cheers

Thanks for the tip.

just write an answer and mark it as accepted please. It will help others and to the system it will show that the question has been answered. As it stands there are no valid answers yet.

I solved it by using:
obj.modifiers['Fluid'].effector_settings.keyframe_insert(data_path="use_effector",frame=5)


text:
Blender Cycles affect incoming rays
So I understand how ray tracing works. And in shader nodes in Cycles you can use LightPath node to tell the renderer how certain material affects the rays that come from other object.
For example if some other fragment (pixel) casts a shadow ray that intersects your material, you can use the isShadowRay to affect the value returned by that ray, up to making the material completely transparent for the shadow ray, i.e. not cast shadows on anything.
That's a very useful node, but is there a way to do the reverse?
For example if my material casts a shadow ray, and it intersects some object, meaning that the shadow is cast on my material from light source. But can I take that returned value and affect it in any way? For example, it could be useful to make the shadow ray always return 0, i.e. no shadows are cast ON my material. I understand that you can achieve that particular effect through, for example, rendering layers, but I'd love to have that input available for me to do mode complex stuff.
Since someone misunderstood the question, I will ask again differently.
Ray tracing works as such:

Cast a ray from the camera
It hits some pixel on our Material
Then many other rays are cast in different directions to test which other objects/materials are around that pixel. Those are shadow rays, transparent rays, diffuse rays, etc.
Each of those rays returns a value. The mathematical formulas are then used to determine the final color of the initial pixel that we have hit.
I want to take those values in the shader and affect them.

What LightPath node does is the reverse of what I want. It affects the result that THIS MATERIAL returns to OTHER MATERIALS that have cast certain rays.

First of all, the "Is..." outputs of the Light Path node are just giving two values: yes or no. If a ray is a shadow ray, the value is yes or 1 which shows as white, if not it's no or 0 showing as black. So if you want to reverse the answer of the question "is this a shadow ray?" then you can simply use an Invert node or a Color Ramp with white on the left and black on the right, or a Map Range node mapping 0..1 to 1..0 and maybe many other ways as well.

Gordon Brinkmann, I appreciate you correcting me on the binary nature of the node, but you still have completely misunderstood the question.

Now your question is more clear, thanks.

You can check Use Nodes on the light object and try controlling the rays from there.  I have a couple of answers with lighting cheats that might give you an idea. - https://blender.stackexchange.com/questions/229624/hide-light-source-reflections-cycles/229642#229642 - https://blender.stackexchange.com/questions/233991/mix-shader-object-semi-transparent-causing-unwanted-light-spots-with-cycles-on/234129#234129


text:
Extruding inwards without creating double faces
I'm trying to extrude the selected face in Cube #1 by pressing E, left click then move along X axis. The desired result is Cube #3 but what I get is Cube #2. Is there any workaround for this as it seems a very simple problem and I find it weird that this function hasn't been implemented yet.
Thank you in advance!

https://blender.stackexchange.com/questions/30874/push-faces-like-sketchup

Press Alt + E and select Extrude Manifold.  Blender will move all the edges of your selection back while creating a new face under the lip, just like you want.


text:
How do I join to actions together (from the dope sheet and action editor) to form one animation?
These videos told me that I need to create actions in the dope editor to make multiple animations on one object. I want two objects' movements to be one animation. I tried animating the second object in the same action as the first, but that just messes everything up. Now I'm just going to animate them in different actions. When I finish that, how do I join them together as one animation?

Related https://blender.stackexchange.com/questions/64904/what-is-the-nla-editor-used-for

show us your blend file

@Chris , edited it into the post.


text:
error when making bake de normal map in blender 3.0
I'm having trouble making the bake of the normal map of an object, as you can see has a stripe, well in the division in the seam of the uv map, as shown in the image

i'm making the scales of a snake.
I'm doing something wrong, but I don't know what.

why do you have an invert node after you image texture node?

I have an invert node, because as you can see the normal map texture is green, not blue. I searched the Internet for a solution for this and found the solution with the invert node

I realized my mistake, I was saving the texture of normal map like jpg, so I saved in PNG format and it worked out


text:
How to store multiple added empties IDs used in a warp modifier so they don't conflict with new warp modifiers?
this is my first time coding for Blender, I haven't gotten around to organizing the code yet. I'm self taught so my code's not the cleanest.
I'm attempting to create a 'dorito' deformer using this code, by selecting a vertex and running this script, it would create two empties that would be used for a warp modifier that would be added to the selected object.  I am using bmesh to access the selected vertex's coordinates so I could add the empties to that location, storing it into the "vertex" variable.
I am storing the return value of the empties to an empty list, but I don't know how to use that to be able to add more empties to a second or third warp modifier making the script actually useful.
Any input is appreciated!
PS: I am scripting this for 2.92.  Just in case there are relevant changes in the API.

import bpy
import bmesh

if bpy.ops.object.mode_set.poll():
    bpy.ops.object.mode_set(mode='OBJECT')

object_data = bpy.context.object.data
meObject = bpy.context.active_object
bm = bmesh.new()
bm.from_mesh(object_data)

bpy.context.view_layer.objects.active = meObject

if bpy.ops.object.mode_set.poll():
    bpy.ops.object.mode_set(mode='EDIT')

#gets vertex position to add empties
vertex = (0,0,0)
for v in bm.verts:
    if v.select:
        vertex = tuple(v.co)

#changes mode
if bpy.ops.object.mode_set.poll():
    bpy.ops.object.mode_set(mode='OBJECT')

#empties list to store empties
empties = []

#adds first empty for warp deformer,  and appends to list
empties.append(bpy.ops.object.empty_add(type='PLAIN_AXES', align='WORLD', location=(vertex), scale=(2, 2, 2)))
#names empty added
bpy.context.active_object.name = 'Parent'

#sets parent name
bpy.context.object.parent = meObject

#adds second empty for warp deformer
empties.append(bpy.ops.object.empty_add(type='PLAIN_AXES', align='WORLD', location=(vertex), scale=(1, 1, 1)))
#names empty added
bpy.context.active_object.name = 'Deformer'
#changes empty used
bpy.context.object.empty_display_type = 'CUBE'
bpy.context.object.empty_display_size = 0.75
bpy.context.object.parent = bpy.data.objects["Parent"]

bpy.context.view_layer.objects.active = meObject

#adds warp modifier
bpy.ops.object.modifier_add(type='WARP')
bpy.context.object.modifiers["Warp"].object_from = bpy.data.objects["Parent"]
bpy.context.object.modifiers["Warp"].object_to = bpy.data.objects["Deformer"]

if bpy.ops.object.mode_set.poll():
    bpy.ops.object.mode_set(mode='OBJECT')

Using API methods.
A common misapprehension in blender is that create / add "anything" operators return the newly created thing, instead the newly created thing is found from context. Eg for add object primitives the new object is context.object directly after the call (if run in OBJECT mode) A newly added modifier sits last in the objects modifiers collection.
That said, it is a lot, lot, lot  easier (IMO) to totally ditch the operators  & instead use related API methods which return a reference.
Below is an operator-less re-rig of question code to run entirely in EDIT mode

Select a vertex

Adds a warp modifier, once again using the related API method new_mod = Object.modifiers.new(...), so we have its reference.  The new modifiers show in edit mode is set, so we can see the result.

Adds two empties, the first is at the location of the vert, the second is offset from the first by the value set for offset These are assigned as the "from" and "to" objects of the modifier.

The empties are given a name to reflect object warping, which modifier, from or to.  Other things to consider would be putting the empties into their own collection.

Looped over the "object_from", "object_to" properties of the modifier.  setattr(warp, k, ob) is equivalent to warp.object_from = ob when k == "object_from".

The offset is in global coordinates. This is converted to local since the empties are being parented to the warping object. Think this answer helps explain the maths used Which matrix to use to transform children local coordinates to global?

Test code.
import bpy
import bmesh
from mathutils import Vector
from bpy import context

offset = Vector((0, 0, 1))

col = context.collection
ob = context.object
mw = ob.matrix_world
mwi = mw.inverted()
me = ob.data

bm = bmesh.from_edit_mesh(me)

vert = bm.select_history.active
# if not a vert then throw error
assert(isinstance(vert, bmesh.types.BMVert))

warp = ob.modifiers.new("Warp", type='WARP')
warp.show_in_editmode = True
for k in ("object_from", "object_to"):
    mt = bpy.data.objects.new(f"{warp.name}_{k}", None)

    col.objects.link(mt)

    if k.endswith("from"): #
        mt.location = vert.co
    else:
        mt.location = vert.co + mwi @ offset

    setattr(warp, k, mt)
    mt.parent = ob

Thank you very much for your reply!  I'm going to test it out and ask you some things about it, I hope that's alright!


text:
Imported images not reflecting onto glossy objects
I have imported an image as a plane into blender and added an object with a glossy shader. for some reason the object is only reflecting the world background (gray color) and not my image. what is going on here?
I am somewhat new to blender, so if my nodes look ridiculous that is why.
links to screenshots
https://drive.google.com/file/d/1-acT8LSEA8DfeA7bH2wXKJGS0KStHsE1/view?usp=sharing, https://drive.google.com/file/d/13zLuH07kLpPKF_5KyJnytsG9kUcOU1T0/view?usp=sharing, https://drive.google.com/file/d/15WfN8UiFRMixwFF-JVjN0z3Rmbagjm3_/view?usp=sharing, https://drive.google.com/file/d/1a4zoWlXMNzNgnvlUCT-qwMwPHgeK_dyK/view?usp=sharing, https://drive.google.com/file/d/1s-ic3xoDEp0MIs1qYDSuPCz6P-e8YpEq/view?usp=sharing
EDIT ok FFeller I tried that and it sort of reflects, but not really. I tried using a reflection plane and it didnt seem to do anything. how to get a more complete reflection?

How to upload an image to a post?

You have to enable the "Screen Space Reflections" on the right side (Properties Panel).

see the edit i made to the question, i cant figure out how to post images in comments


text:
Missing Parts When moving from Blender to 3D Print
Since all the good answers up here taught me a lot along my way into modelling, I'm coming back to you with a question:
I've been modelling a ring in blender and would like to print it with my Photon. I know it's quite fragile but the wires are as thick as the support columns.

One basic thing I never understood: When creating a mesh in blender, will I have to fill it in for printing or is this happening in the slicer?
When I'm trying to print (and also when making solid in MeshMixer) only one of the spirals is printed - can you help me what happened to the rest?

Link to the file:

Can you give your question a meaningful title? People who can help you and those who have the same or a similar problem can find your question that way.

The file attachment is an STL file not a Blend file (Post the Blender fIle) another place to attach Blend file is https://blend-exchange.com/ .  Also when importing your STL file into Blender it crashes Blender.

Thanks a lot @RickT I attached the Blender File


text:
How to combine different textures into one
Thanks to @moonboots , I managed to edit the textures of our face model for medical research. Now I'd like to combine the base texture with the two additional ones for exporting and sharing the model.
Could someone provide me with a link or a short explanation how I can do that?
Thank's a lot!

Edit:
I tried Moonboots approach to combine the textures:

Unfortunately that has as a result that the image of the middle texture is used also as the image for the third texture:
1st spot is working fine:

That's how the 2nd spot should look like:

That's how it looks like - same texture as spot 1:

Is this a problem of UV editting? Once I want to check if the uv maps are positioned correctly, I can't manage to choose the three different ones I've created: spot 1, spot 2, rest. How can i get back to that?
Thanks a lot

You can't mix several textures at once, you can only mix 2 by 2. In your case you need to build this kind of setup:

When you're glad, you can bake everything (but always keep the original setup somewhere in case of problem):
Make sure that you've chosen the Cycles render engine, create a new Image Texture node, give it a new image (choose its size), keep it selected, go into the Render panel > Bake, Bake Type > Diffuse, under Influence disable Direct and Indirect, click on the Bake button. Now you can plug the new Image Texture into the Base Color input of the Principled BSDF:

That's a great advice, thank you! But as you can see in my screenshot, I've just one additional texture combined to the main texture. Is there a way to combine all three in one step? Thanks a lot!

@fernweh73 oops ok I've edited

thanks a lot, I edited my post for precision.

I'm a bit lost, maybe you should tell what images you have and what you're trying to achieve


text:
How to incorporate images into my textured model
Another medical use case I need your help with!
I have a face scan with an image texture and I'd like to project content of another image on top without the need for manual texture painting.
This time it's a skin lesion that I want to incorporate in the textured scan of a healthy skin.
I've tried with the clone tool and with manual uv-editing but I'm not sure of the right approach. Could you please provide me with maybe a link to the right tutorial or a few words on how to achieve this aim?
Raw model:

Textured model:

Picture of skin lesion:

Awful representation of what I'm aiming for:

Thanks a lot for your help!!!
Edit:
I tried incorporating the tips you gave me:

Some questions:
What affects the dark seam around the picture and how can I get rid of it?
How can I play with the colors and make the added image a bit darker?
Why did we create a new UV Wrap in the properties panel?
Thanks a lot!

You can mix the existing material with the image through a (Color) MixRBG in Multiply mode, make a second UV map for the spot itself if necessary, in that case use an (Input) UV Map node:

More details about the second UV map. Let's say that you use the already existing UV map for the base skin texture, here is what your material will look like, you'll have the Texture Coordinate (UV output) plugged into the Image Texture. For the spot, you'll need an (Input) UV Map:

To create a second UV map, go into the Object Data panel > UV Map, and click on the "+" button, keep this second UV map selected, select it in the UV Map node:

Then in your 3D view, in Edit mode, select the part where you want to see the spot, press U to unwrap and in the UV Editor place the UV over the skin spot (as you see I've painted white all around the spot so that the mix with your base color works fine):

Invert the selection with Ctrli in order to select the rest, unwrap and put the UVs over a white part of your image so that it won't be affected by any color:

Edit: From your last version, there is a problem with your second UV map, as you see some faces are over the spot part of your image while they should not:

To fix that, select the faces that you want the spot to appear, then Ctrli to invert, then unwrap again, scale down and put the UV faces over a white part of your image:

Hello Moonboots. Thanks a lot for the advice. I incorporated the image texture as color1 and the spot as color2 but naturally can't define its position. Could you please briefly explain me how to add a UV map at the correct position? Thanks a lot!

Hello @fernweh73 I've edited my answer, please tell me if you understand

Hey @Moonboots thanks a lot! I tried your tips and edited my answer. could you have a look?  almost there :)

Could you please pack your image (File > External Data > Pack Resources) and share your file? Use workupload for example

Great, thanks a lot! Could you tell me how I can export the project as obj+ 1 combined file of textures?

You need to bake the diffuse onto one unique texture (you'll find some YT tutos on this topic), then export the object as wavefront (.obj), but for an obj you probably can't pack the image texture so I guess it needs to be in the same folder


text:
How can I add a new menu to the shader editor with a shortcut?
am trying to add a menu into the shader editor that can be accessed by SHIFT Q shortcut,
if i add the same menu in the 3d viewport it works but not in the editor
my code
class shader_menu(bpy.types.Menu):
    bl_idname = "evx.shader_menu"
    bl_label = "Shader_menu"

    def draw(self, context):
        layout = self.layout
        print(123)
        layout.operator("wm.open_mainfile")
        layout.operator("wm.save_as_mainfile")

def register():

    for cls in pie_classes:
        bpy.utils.register_class(cls)

    wm = bpy.context.window_manager
    kc = wm.keyconfigs.addon
    if kc:
        km = wm.keyconfigs.addon.keymaps.new(name='3D View', space_type='VIEW_3D')
        kmi = km.keymap_items.new(main_shortcut.bl_idname, type='Q', value='PRESS',shift=True)

        addon_keymaps.append((km, kmi))

        km = wm.keyconfigs.addon.keymaps.new(name='shade Menu', space_type='NODE_EDITOR')
        kmi = km.keymap_items.new('wm.call_menu', type='Q', value='PRESS', shift=True)
        # kmi = km.keymap_items.new('mesh.primitive_cube_add', type='U', value='PRESS',shift=True)
        kmi.properties.name =  shader_menu.bl_idname
        addon_keymaps.append((km, kmi))
    # print(addon_keymaps)

Hello, could you post a sample of your code ?

TL;DNR:  As far as why the shortcut is not working:
    km = wm.keyconfigs.addon.keymaps.new(name='3D View', space_type='VIEW_3D')

You need to change VIEW_3D to NODE_EDITOR.
Long answer:
It is not entirely clear what you want to do, but to add a new menu to the Node editor header, you need a command like
    bpy.types.NODE_HT_header.append(shader_menu_draw)

Here is an simple example, although it puts a button in place, you can make a menu instead fairly easily.  Note that the menu entry goes at the right end of the header -- that's a limitation in how Blender handles additions to menus.
import bpy
from bpy.types import Operator

bl_info = {
    "name" : "sshade",
    "description" : "HOWTO examples for adding a menu to the shader editor",
    "author" : "Marty",
    "version" : (0, 0, 1),
    "blender" : (2, 93, 0),
    "location" : "Node",
    "warning" : "",
    "support" : "COMMUNITY",
    "doc_url" : "",
    "category" : "3D View"
}

menu_keymap = None

def initialize_keymap():
    key_config = bpy.context.window_manager.keyconfigs.addon
    if key_config:
        key_map = key_config.keymaps.new(name='Node Editor', space_type='NODE_EDITOR')
        key_entry = key_map.keymap_items.new(SHADE_OT_demo.bl_idname,
                                                            type='Q',
                                                            value='PRESS',
        )
        menu_keymap = (key_map, key_entry)

def deinitialize_keymap():
    if hello_keymap:
        key_map, key_entry = hello_keymap
        key_map.keymap_items.remove(key_entry)
        bpy.context.window_manager.keyconfigs.addon.keymaps.remove(key_map)

def shader_menu_draw(self, context):
    """ adds a menu entry when the function is added to an existing menu"""
    self.layout.operator("shade.demo")

class SHADE_OT_demo(Operator):
    """A very stupid operator entirely for the purpose of demonstration"""
    bl_idname = "shade.demo"
    bl_label = "say hello"
    bl_description = "say hello"
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(self, context):
        return True

    def execute(self, context):
        self.report({'INFO'}, f"menu hit")
        return {'FINISHED'}

classes = [
    SHADE_OT_demo,
]

def register():
    for c in classes:
        bpy.utils.register_class(c)
    initialize_keymap()
    bpy.types.NODE_HT_header.append(shader_menu_draw)

def unregister():
    for c in classes:
        bpy.utils.unregister_class(c)
    deinitialize_keymap()
    bpy.types.NODE_HT_header.remove(shader_menu_draw)

if __name__ == '__main__':
    register()
```


text:
How can i slow down and make a colision with this Particle System (smoke)?
so im working on a personal project and im trying to do a chimney that emmits smoke. I manage to get the particle system right but the animation of the particles going up is way too fast.

The other big problem im facing is, how can i make this smoke interact with the roof of the chimney, so in that way the smoke dont clip through the roof, and go to the sides ?

Thanks !
EDIT 01/07/2022
Manage to get the speed right with the help of Gordon Brinkmann, but still facing the interaction problem.

For the speed at which the particles rise: you have velocity settings for them which you can see in your screenshot. If you turn them down, they'll move slower.
Another possibility would be to have a value > 0 for Damp under Physics > Forces in the Particle Settings.
For the interaction with the chimney: I guess the chimney is already a Collision object, so to take the size of the smoke into account, you have to enable Size Deflect under Physics > Deflection. By default this is turned off and only the center of a particle is used for the collisions.
However, with randomly varying sizes you can get the problem that a particle is born which is too large to "escape" the chimney. I personally wouldn't mind too much if a larger particle goes "through" the rooftop of the chimney as smoke could also wrap around obstacles. Of course this wouldn't look perfect, but since you only have spherical particles and no real smoke, they won't deform around collision objects.
Physics > Forces and Deflection:

Hey, after your instructions i manage to get the speed just right, it was really the Damp levels messing around, but i still have the problem with the interaction with the chimney, after i checked the Size Deflect Box the particles still go through the roof, i tried to use a collision modifier in the chimney itself so it interacts with the particles, but i doesn't seems the right way to do, the particles is very erratic behavior and goes everywhere.

The Size Deflect uses the size which you have set under the Render settings where you choose which object to use for rendering the particles. I guess it might be depending on the scale of the object that the visible size differs from the set particle size. What do you mean with the collision modifier? For the collision with particle you need to enable Collision on the chimney found in the Physics tab, where you also find things like Rigid Body, Soft Body, Fluid and other simulations.

It worked ! After i tried to adjust the size of the rendering particles i made a new plane at exactly the shape of the roof that i wanted to the particles colide and spread, i made this plane a convex shape, pointing downward to the botton of the chimney and assign this shape as Physics - Collision, that way when the particles is hitting the highest point of the convex shape they tend to spread outwards of the shape. Thanks !


text:
How can I make this rope swing with wind animation holding the tire and being tied to the branch?
So what i'm trying to do is make a animation where the rope holds the tire at the end and keeps the hold on the three, but the swinging animation will happen when a gust of wind hits the rope/tire. How can i make this ? i Tried to use rigid body, but all the rope falls to the ground and i dont know how to manage the end of the rope holds the tire.
Here is a pic

EDIT 17/07/2022
I used @moonboots answer, but if you find that your animation kind break after the steps like this :  You probably doing the same mistake that i did. So let me be clear, before even u begin with the instructions make sure that when you create the cylinder do Ctrl + A and Apply Rotation & Scale only after this u can continue with the steps. Oh this is important too, your cylinder has to be subdivided so it can move naturally like a rope or will gonna look like is just a straight object leaning to the side

And that is it, thanks for all the help, especially for @moonboots. If you want a more detail about this solution he made a video explaning how to do this, here is the link: https://www.youtube.com/watch?v=OMwDqlRzJ4g
Here is what looks like after all this !

Pin the top vertices of the rope.  You may need to do more depending on what you want to accomplish.

Here is a simple solution:
Create a long vertical subdivided plane (object 1), a long vertical cylinder for the rope (object 2), a tire (here a ball, object 3) and a Force Field (here a Wind):

Give a Surface Deform modifier to the rope with object 1 as Target, click on Bind. Select the ball, shift select the rope, switch to Edit mode, select 3 vertices of the tip of the rope and press CtrlP > Make Vertex Parent. Create a vertex group at the top of object 1, give it a Physic > Cloth with the group as pin group. Keyframe the Strength of the Wind to create the swing:

The swing will be 2 dimensional (here it won't work well on Y). If you want it to be 3 dimensional, use the same method but with an object 1 that is 3 dimensional (a kind of cage around the rope), and give a Mesh Deform modifier to the rope. Play with the Stifness > Shear and Bending values of object 1.

+1...but uhm...why isn't the rope fixed to a tree? and why is the tire a sphere in your example? i guess it is because "how many roads must a man ...." ;)

tires and trees need a completely different solution, mine only work for balls that are hanged to nothing, but please don't tell any one

balls...of course...normally your comment must be flagged as sexual harassment....you know that, don't you? :D

I know, plus the rope is not really a rope if you know what I mean

that's pretty embarassing....and i think you will be banned from SE a minimum of 3 years, 1 month, 4 days, 1 hour and 5 minutes. :D and you deserve that for being so horny....

I know but I try to get hired in the 3D animation p*rn industry

and i thought you were already working there....but maybe i confound 3d animation and reality..... :D

Man, come on, of course, how do you think I got my skills in Soft Body, Fluids and so on

That’s why you don’t know python….‼♂

Hey, i follow u instructions and kind almost worked, idk whats happening but at the final part when i put the cloth physics the animation of the rope and tire goes crazy, i made a video doing the solution that u told here is the link https://youtu.be/07TsfcvRcto  Am i  doing something wrong in the process ?

You need to subdivide your cylinder, also when you parent your sphere to the vertices of the cylinder, choose some vertices that are around the edge loop, not 3 adjacent vertices. And apply the rotation of your objects. If it still doesn't work please share your file.

I tried the solution above, and it keeps the same problem. Here is my file that is giving the problem https://drive.google.com/file/d/1QYuEe2APOQTKFE2TXU1cFfZR4iqlSkTx/view?usp=sharing

Select the cylinder and the sphere and Ctrl A > Apply Rotation & Scale, put the sphere under the cylinder

IT WORKED ! it was really the Apply Rotation & Scale option that i forgot to do it messing things up. The good things is after all the tries of different form do to i understand the idea i can apply for different things.

Great, by the way it has inspired me a tuto: https://youtu.be/OMwDqlRzJ4g

Great video, instructions pretty clear. I already saved too if i forgot something in the process, also i add your video at the solution of the question ! I appreciate


text:
getting error : location: <unknown location>:-1 in "shading" when adding no matter what to the board
Thank you all! I was able to fix it with the installation of the version Blender 2.93.0 Alpha (experimental build) and it is working quite well

The full error in 2.92.0 ... was:
location: <unknown location>:-1

bpy.ops.node.select(wait_to_deselect_others=True, mouse_x=779, mouse_y=162, extend=False, deselect_all=True)

bpy.ops.node.add_node(type="CompositorNodeRLayers", use_transform=True)

Python: Traceback (most recent call last):
  File "C:\Program Files\Blender Foundation\Blender 2.92\2.92\scripts\startup\bl_operators\node.py", line 138, in invoke
    result = self.execute(context)
  File "C:\Program Files\Blender Foundation\Blender 2.92\2.92\scripts\startup\bl_operators\node.py", line 129, in execute
    self.create_node(context)
  File "C:\Program Files\Blender Foundation\Blender 2.92\2.92\scripts\startup\bl_operators\node.py", line 92, in create_node
    node = tree.nodes.new(type=node_type)
RuntimeError: Error: Cannot add node of type CompositorNodeRLayers to node tree 'Shader Nodetree'

location: <unknown location>:-1

I use blender version 2.92.0 and no addons
added  "vector displacement" and it seams blender respectively shader does not recognice the handles anymore ... so I can not move ore tie the boxes ... but I can still ad others and change the adjustment

I did save
and restart
and repair blender
and reinstall blender
and save as
...
nothing did work so far.
is it a bug, ore just me ?
thanks for the help!

In what context does error appear? What actions do you perform to get the error? Do you use any addons? What do you intend to add, what type of nodes? What Blender version do you use? You can [edit] your question

The "unknown location" warning  pops up, but IMO this is not the issue here. The error is re trying to put a compositor node into a shader node tree.  Try adding that node in the compositor space.

well I try to bumpmap a material based on a noise shader ... this seams not posible in the compositor to me ... I redid the prozess again and got the error even earlyer after linking the image to the material

I just did open a new project and went directly to shading without any action and got the same error again ...

thank you all for reading and commenting!!! ... I fixed it by myself by instaling the blenderversion 2,93,0 Alpha ... and it is working as expected :) ... so I guess it is just a bug ... I will as well edit my original post to include my fix ...


text:
One object with multiple elements ,different colours to elements inside object
After applying a particle instance I now have 1 object that has hundred of elements inside
I would now like to assign random colours to the different elements
I know how to do it to differnet objects and particle systems but not with one objects that has multiple elements inside
The object info node , random output is only relevent when the object is duplicated , but the elemnts inside still have the same colour

The screenshot shows a sphere with hair particles ( left  )  , for the rendered view I choose path
Then I created a small cube ,  and added a particle instance  modifier , pointed that to the sphere particle system   and applied the modifier
The result is a sphere (object ) made out of cubes ., right part of the screen.
ONe object with multiple mesh islands
I know how to add differenet materials  to differet faces , and I could do that here too , but we have around thousand cubes here , so doing it manually requires a lot of work
I basically want 1 material , and apply random colours to the separate mesh islands .
SO far , I have.t found the correct   node module yet .
On the other hand , If I would do it the other way , choose the cube as a rendered object for the particle system , then the particle node , random output  would do wha I want .
But this is not relevant here , since I'm working with an instanced particle object that is applied
I tried different textures , texture input node set to generated and going into a colour ramp ..all with mixed result , because something one cube has 2 different colours .
So bassically a need a module that goes into a colour ramp , and apply  1 colour to each cube , in a random order
The particle node random output only works for particle systems and sadly not in my case ( 1 object , multiple mesh islands )
Then we have the object info node , this will work on different objects only , but sadly not mesh islands

Please show a Blender screen capture with you settings.  This will make your question clearer.

Do you mean to say one Mesh has many islands of connected vertices?  Perhaps that lingo in more Blender oriented.

Any face of a mesh can have a different color.  Please search ... assign different colors to faces of a mesh.

Please see this tutorial https://www.youtube.com/watch?v=3R0842q6jfE

I would encourage you to change the word [elements] to [mesh islands] everywhere in your question.  Many software products have a lingo to them.

https://blender.stackexchange.com/questions/120290/procedural-random-different-colors-based-on-normal-direction/120294#120294

Assuming Blender Render.
In [Edit] mode  you can place the mouse over a connected vertex group and
press l the second letter of  B(l)ender to increase your selection .
Then in the materials panel pick one material and click
[assign] button.

Particles can be created with different colors in groups or duplicated faces or material nodes so it may be easier to let the creation of particles assign colors for you.

It comes all down to this , create a cube , go into edit mode and  make duplicates inside it .
now go out of edit mode and assign 1  material to the object , with a node system that controls random colours to the separate mesh cubes inside the object .
Hope this clear things up


text:
Why is triangle used instead of Quad?
Why is triangle used instead of Quad?
Why is triangle used instead of quad in the first screenshot as in the 2nd screenshot?
I thought diamond shaped quads could be used?

I'm sorry, because I was sick, I couldn't look at the computer. In one of the videos I watched, while optimizing the model, highpoly used it this way in the other, I wondered why he used it, I couldn't understand why they did it. Can you suggest a source that can give me information about this subject?

You can use triangles as long as it doesn't create any problem

I don't know if I understood correctly, the use of quad and tris is a bit of the artist's choice.

If tris don't bother you when you work on your topology, and if it doesn't create any artefact when rendered, it's ok to use them, same for ngons. Using only quads is often cited as a rule because it prevents this kind of problems, but as soon as you understand why and when it creates problem you can use them

You can use tris in hardsurface modeling, only optionally. Hardsurface modeling requires less details in the mesh than deformable objects requiring more quads than the former. Quads have advantages. For example, it is easy to select rings of edges or faces, or box-select areas.

If tris don't bother you when you work on your topology, and if it doesn't create any artefact when rendered, it's ok to use them, same for ngons. Using only quads is often cited as a rule because it prevents this kind of problems, but as soon as you understand why and when it creates problem you can use them.
In your case tris or quads will give the exact same result. But using quads won't represent any advantage, it will even make the selection of the half-circle edge more tedious, if you want to create a bevel for example:

If your shape is meant to stay like this, use tris. If you plan to create extrusion for example, a better topology would be this one:


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How to link Anaconda3 environment to Blender 2.92 on Windows
My problem
Since the release of Blender 2.92, my anaconda3 environment does not work anymore with Blender...
I have this error at startup :
Unable to find the python binary, the multiprocessing module may not be functional!

My configuration

Windows 10 - version 20H2, build 19042.867
Blender 2.92.0
Anaconda3-2020.11
An anaconda3 environment called "blender" with python 3.7.10
A symlink to the conda environment as shown here :

Several environment variables :

What I already tried to do
This configuration was perfectly working on my previous version of Blender (2.91.2).
I uninstalled/reinstalled everything, resetting the exact same environment variables, adding some others ... It still does not work ...
I saw a fix done in December 2020 related to this issue, but it seems that it only concerns developer versions of Blender : https://developer.blender.org/D9775
EDIT #1
I have found a little workaround to this problem. I have written a small
script that starts Blender through the "Anaconda3 prompt".
So I guess that the problem comes from a wrong configuration of the environment variables, but I can't tell what's wrong for the moment ...
Here is the small script :
@ECHO off
set system_drive_name=%CD:~0,3%
set anaconda_root=%system_drive_name%Users\%username%\anaconda3
call %anaconda_root%\Scripts\activate.bat
start "" "%system_drive_name%Program Files\Blender Foundation\Blender 2.92\blender.exe"


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Weird shading issue in rendered mode
I have enabled smooth shading with and without auto smoothing, played with the normals, and tried a million other fixes but i after many hours of trying have made no process, i also searched online and didn't find any fixes to this issue
how can i fix this? any help is much appreciated! :)
link for file here!

Wireframe please?

added the wireframe picture now

That’s not a full wireframe, go out of edit mode and enable wireframe under shading options.

I uploaded the file here so download it and view it, if you figure out a fix, lemme know :D thanks!
tempdrive.io/us/xnfuyhx0

Ngon is the reason, I believe, the one between inner and outer border edges. If you cut edges at least until it's convex and not a curvy one it would become better

This is happening because of the ngons. If you look your model from side, you'll notice the face is not actually flat.

There are two ways to fix them.
First(quick and dirty): use Weighted normal modifier with Keep Sharp option enabled.

The shading is better now. However, the topology issue stays still since the Weighted normal modifier changes normals only.
Second(better way to handle this issue): Recreate the model and use Weighted normal modifier on it. There are unnecessary bevels(like the "triangle-shaped" bevels that will create the shading issues on your model. Moreover, they will create unnecessary vertices.
If you want diagonal face with bevels, the topology should look like this:

And because this topology still makes ngon on the top(which will make shading issue too), use Weighted normal modifier to fix the shading issue.


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Animation playback aggressively eats memory, doesn't give it back until program is closed and reopened
Blender is smooth as butter when I first open my file. I can work and move and edit etc with no lag. But after a few paybacks of my animation it will become more and more laggy. Taking a look at the task manager, I notice that during animation playback (a short 3-4 second looped anim) the memory usage will slowly climb higher and higher, resulting in an unworkable environment after a few paybacks and blender does not give that eaten memory back until I save and fully close and reopen the program.

Is it an image sequence you've imported?  Or what type of animation, is there any physics system being used?

Two active rigid bodies, and a few passive. Small repeating marble sequence. Some shaders, keyframes, and an hdri. Nothing fancy, no image sequence.


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How do I stop my texture from stretching when I pose my character?
Quite simply, I've applied a simple image texture and matching normal map to a character and rigged him. When I pose my character (i.e. bend his knee) the texture becomes undesirably skewed and deformed. Is there a way to have the texture scale or move when the mesh deforms as to retain the quality?

It should. Can you share screenshots?

Short of procedural textures, I don't think there's much you can do, if you intend to modify the texture solely.
However, if you were to modify the way the geometry, you can get away with a hidden pipe, by making a much longer tube with a repeated iteration of the joint texture, and rigging it so that it doesn't stretch.
Fundamentally, this is a rigging/unwrapping problem, and would be best solved that way, especially if this is for export.

In real the material on the knee would be either

compressed when the knee is straight and normal when it is bent ... or ...
normal when the knee is straight and stretched when the knee is bent.

If you want to "float" it out of thin air, you need to hide some extra geometry below the surface, like pi75 mentioned in the comment above.
Proof of concept


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Greasepencil strokes disappear behind geometry when rendering
I am wokring on a project using Greasepencil to add detail to 3D geometry.
Everything looks fine in the viewport, but as soon as I render, some of the strokes that are close to 3D objects start to disappear behind them, while others just appear very jagged.
What is the difference between the grease pencil rendering in the viewport and the render? And is there any way I can make grease pencil render behave like it does in the viewport?
It just seem that when rendering Blender calculates the depth of the grease pencil strokes differently than in viewport.
In the past I've usually fixed this by moving the strokes further away from the surfaces, but this is not optimal, especially when the object is not going to be viewed from just one angle.
Viewport rendering is not a great solution for me because I intend to do some compositing in Blender.
This is how the grease pencil objects look rendered:

And this is what it should, and does look like in the viewport:

2 years later, and it seems to still be an issue. However I think I found a culprit. It could be that the camera size too small, or the camera in general is too far away. It's usually at 36mm, and in my case had it in 11mm, and the same issue happened to me, but after returning to it's original size, I got to work again. But then I decided to move back, and the issue came up again. So yeah, that's the only things that comes to mind
Edit: What I ended up doing in my case, was to convert the GP detail into mesh and then use the lineart modifier to bring them back, and somehow it works fine at far and close distance


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Edit Linked Library add-on for 2.8
Is it possible with Blender 2.8 to go directly to the source file of the linked object, from the destination file, as did the "Edit Linked Library" addon that works in 2.79?
If no, will this addon be updated soon?

Edit Linked Library is shipped with Blender 2.8x, you just need to enable it...

You can enable Edit Linked Library in the preferences (Edit > Preferences > Add-ons).


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3D view pie hotkey (or menu access) on Mac
I'm a Mac user and everybody knows some hotkeys are different from Linux/Windows to Mac, and with some effort I can find almost all of them, except 3D View Pie Menu, with tilde key.
I have a MacBook Pro with Tilde key on keyboard, but doesn't work, and I have an extra Mac keyboard and doesn't work too. The Mac keyboard is different and without some keys, so I bought a new windows keyboard just for that, but still not working. Is there anyone who knows how to access 3D View Pie Menu on a Mac using some hotkey or accessing from the menu on the top?

I managed to locate the listing for the shortcut I believe you're making reference to. It wasn't easy to find. Once you know where it is located under the Keymap category within User Preferences, you can try to either target it using scripting, based on its name (In this case, VIEW3D_MT_view_pie), or, simply create an alternative keyboard shortcut, which will grant you access to the feature without use of any problematic default keys.

Actually it is the tilde key, but without the shift.  The key has the back tick and if the shift is used you get the tilde.  On the mac, just hit this key without using the shift.  In other words, it is the back tick key.


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Speech driven facial animation
Is there any way to animate face and lip sync with audio input using machine learning algorithms in Blender ? I mean how can I controll the rigs and give them a value provided by python script for. The idea is to do a dynamic lip synchronization.
I appreciate any help ! thank you

Hello, this question is a bit too broad for this site. We try to keep questions and answers focused so it's easier for everybody to find relevant information. Maybe try with the first steps you've taken on this project and where you're stuck ? Cheers

This is a wide area, but I did have one thought about it myself:
The eSpeak speech synthesizer can output phoenomes instead of sound. You could make something to line up shape key keyframes based on this, although timing might be an issue. You might look into either the eSpeak Python api for synthesis timing check on the words, or even try the Descript project: they might provide synchronization data for the layman.


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Why do my lights not show up on my render?
I'm new to blender and my spotlights don't seem to be rendering. I'm using Blender 2.80 EEVEE and none of my lights seems to be showing up. I have some materials that have a bright emission and they're the only ones that appear. Any idea what could be causing this?

Edit: Link to the file - https://drive.google.com/drive/folders/1uj3xP9KGa8t3QJMq4hFzz7WsgOX9BiXS?usp=sharing

please provide blend file

You have a lot of hidden objects intersecting each other and they are gigantic.  Look at the first image, I had to zoom out a lot to see those objects. You need to clean up your scene, organize your outliner and delete what you don't need.
Note that hidden objects (eyeball icon) are only hidden in the viewport.  The camera icon will hide an object during a render.


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My character looks wrong even though everything is ok!
While I was examining a model made in blender, I came across the following image:

My character's textures are in very good condition. you can see this in eevee mode =

but the situation worsens when I switch to cycles mode. When I looked at the shaders of this scene, I came across a "group". this =

Even if I put a white "emission" instead of this group, it didn't work.

even in eevee mode, one of the reflecting spheres from the test renders appearing in the lower right is black.

I will be glad if you help me. good day!

Make sure your GPU drivers are up to date, or in the case of AMD, make sure there are no issues with the current drivers that conflict with blender (It happened once - around Feb this year).

I am using "Intel driver support assistant" and recently updated my driver. Although my graphics card is very bad, it is also up to date. it also got an update a few days ago. when I opened this file a few months ago there was no problem. I think the problem has a different cause. but thanks for your comment anyway!


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Adaptive Subdivision eating RAM incorrectly? Fails all GPU renders regardless of settings
I've been working on an animation project for months now, that started in Blender 2.8. The animation includes one photo-real character that I am using a Displacement Map workflow for pores and small skin detail, rather than normal + roughness maps. Basically a Film Res character.
I have 6 subdivision levels I'm working with in Zbrush, and load the lowest into Blender to work on the animation, and then rely on Adaptive Subdivision to tesselate the model throughout the animation depending on the camera's location. Far away, I do not need all that pore detail as geometry, but in close-ups it definitely makes a difference.
This has caused me an unreasonable amount of trouble shooting time, especially after upgrading to Blender 2.9+. Adaptive Subdiv being active makes my scene impossible to render (it of course took me a long time to determine that as the absolute cause). As you will see in the images below, there is no reason Adaptive Subdiv should be eating up over 100% of my RTX 2070 Super's 8GB VRAM, yet it does.
In the images below, I have a fresh scene, where I've only loaded my character's body, adjusted render settings to be more efficient, and then fiddled with the subdivision modifier / render settings. I am using the wireframe node on a base material to visualize the tessellation.
First is Adaptive Subdiv working in 2.83 (though the Max Subdiv render setting does nothing).
Next are images of successful renders using normal Subdivision in Blender 2.92. Here you can see the tessellation working as expected, and reasonable memory usage as the polygon count increases.
The last three images are failed renders using Adaptive Subdivision in Blender 2.92. Regardless of settings configuration, the renders fail with an Optix error. CUDA renders take unreasonably long to build the BVH and often also fail. The memory usage is dramatically more than the normal Subdiv Modifier, even if tessellation should be the same or less.
If anyone has any information that may help, I would really appreciate it. The project is basically done and I'd like to avoid having to version everything down to 2.8 to complete it. Don't even know if that would work.
Thank you in advance!
Error:
bpy.context.space_data.context = 'RENDER'
Failed to build OptiX acceleration structure
OPTIX_ERROR_INVALID_VALUE in optixAccelBuild(context, NULL, &options, &build_input, 1, temp_mem.device_pointer, sizes.tempSizeInBytes, out_data.device_pointer, sizes.outputSizeInBytes, &out_handle, background ? &compacted_size_prop : NULL, background ? 1 : 0) (device_optix.cpp:1208)

Finally figured out what has been going on.
For some reason Blender is coded to stack the Standard Subdivision settings ONTOP of the Adaptive Subdivision. So if you uncheck Adaptive Subdivision, and have any subdivisions in the Render Subdivision settings, those subdivs are added along with the adaptive ones.
Set original subdivision settings to 0 before checking Adaptive and it seems to work as expected.
This definitely does not feel intended, and is super unclear for the user.
Hope this helps someone else.


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Displace modifier RGB to XYZ Direction, how to invert on the x axis only
I have two high poly objects, both with a displace mod and their coordinates set to global, their  direction set to 'RGB to XYZ', the strength set to 1 and the midlevel set to 0 but they both use a slightly different texture map that's actually a movie. my goal here is to get some really jagged points based on the texture from some of the geometry and point them all towards a specific vector from where they're grabbed from. the thing is my first one is angled exactly how I want but the other one cant seem to 'mirror the first ones angle. what I thought I should do is go into the Material settings > Colors > Clamp and disable it and then make the Colors > RGB values negative numbers but this doesn't seem to work despite the tool tip in the Clamp bool implying as much. I've tried several things, including trying to use some nodes which I know nothing about and never even got close, and I'm still not sure how to reach my goal. My main questions are:

Dose the clamp work like I'm using it?

Is there a way to combine two displace mods that doesn't stretch the points along two axis being used for each direction?

Can I get any advice on how I could achieve my goal?

All help is greatly appreciated and ill give more info as its needed.

can you provide your blend file?

@Chris Please encourage new users to go through other methods of describing their issues before requesting blend files as per this meta post.  In this case, I think just a simple screenshot illustrating what OP wants would be much more helpful than a blend file.

Separate XYZ node and multiply the desired channel by -1?  Or perhaps invert node

@PGMAth: my personal opinion is, that you can help best with a blend file, because then you can be sure it is the solution for the problem, because you can try it out. With images you can only guess what it might be - but you can never be sure. And i think it is much easier for every beginner to provide the blend file than lot's of images or even gifs. I am speaking out of my self experience ;) and i hope the most important is here to help the people and not to follow guidelines. I just wanna help, because i got lot's of help here. Just my 2 cent.

@Chris if you have concerns on the policy please bring them up on the linked meta thread.

@PG: then i just wonder why you didn't tell Kylie that she should just ask one question? Why did you critizise me but not her? Do you want people to help here and have a growing community or do you want just a few people who are willing to keep all policies and all rules? i never read any rules, policies here....with the exception of: how to ask a good question. And if you really think, just 2% of the users have read them all or just a few of them....then i think you are not realistic. Because 98% of the people want just quick solutions for their problems like me. This is just my opinion. ;)

I've edited to include both.

@PGmath: This is my first post but I've been using StackExchange for a while so i know how to sort of ask my question but thanks for linking me to sources for better practices!

@Chris I really don't want to discuss this further here, that's what meta is for. The linked meta post (which has been featured on the sidebar for a couple weeks now) addresses our thoughts on most of what you raised, but if you disagree then please feel free to raise your arguments there (that's what meta is for so the community can formulate our rules together, but it only works if everybody who has opinions uses it). As far as this post goes, the only thing I felt was necessary was a simple illustration as I mentioned so I'm not sure why you're asking why I didn't bring up anything else.

I have solved my issue using nodes rather than a modifier thanks to the suggestion @Allen Simpson commented. I'm fairly new to the workflow and application of shader nodes but I will try to explain in more detail.
My issue was that I needed to turn my texture map into a Vector Displacement node to point my displaced geometry in a consistent direction something the Displace Modifier can also do using the textures RGB values. the only issue is the modifier method requires you to set RGB values in the Texture Properties > Colors > R,G,B and it only accepts values 0-2. you can use the strength value in the Displace Modifier to multiply that value even in the negative direction but it applies it to all 3 RGB values equally. not sure if there is a way to do what what I needed via the modifier but that's ok.
After giving the shader nodes another go I found the Separate RGB node and everything clicked from there. After feeding it my color from my Image Texture nodes output I fed the R value, which represents the only axis I wanted to modify, into a Math node and multiplied by -1 and fed the output and the G and B into their respective X, Y, Z values in a Combine XYZ node. Then I dropped that output into a Vector Displacement node to give the displacement its direction.

With this solution you can easily build a vector by adding a Math node to each of the other values on the Separate RGB node before combining them as XYZ!
Also to answer my own other questions;

Clamp works like Clamp in the Mirror Modifier in that IF there are any values below 0 and Clamp is turned on, it reverts to 0 but it does not automatically grant your colors RGB values to go below 0. No such thing as a negative color value after all. Not sure if there is a way to get the negative values for the Displace modifier but its not that way. Nodes do a good job of letting you take a value from the color and then mod it as you need. Much easier imo.

Not sure but it seems like a harder way to do this, but it would be good for getting a different effect. I think it can make really psychedelic kaleidoscope like geometry animations?


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Rigid body bounces away when starting animation
I'm trying to create an animation in which a ball is placed on a plane which I'll then animate by rotating it in different directions. However, as soon as I check the "Animation" box under Rigid body settings for the plane, the ball bounces away rather than fall down on the plane.
I've attached a gif below which hopefully is helpful.
Here is a link to the blender file as well: https://pasteall.org/blend/660da9a9fcac418eb1c1d67263c1425e
Any suggestions on how to resolve this would be incredibly helpful.

please provide blend file, because there are many reasons, why this can happen https://blend-exchange.com/

Hi Chris,
Of course! Here's the blender file: https://pasteall.org/blend/660da9a9fcac418eb1c1d67263c1425e
Thanks!

moonboots was quicker than i was and he is right - because he is THE MASTER ;)

i think you missed the 'S' for Superman.... :D

aha I'm the Beastmaster  ;)  https://i.pinimg.com/originals/6c/5e/13/6c5e13d48816a4670f415c9393263f80.jpg

Apply the scale of your cube (maybe you could also disable the Animated option and switch it to Passive, it depends on what you want to do with it)
Result after applying the scale with CTRL +  A Scale:

wow, Great animated result added moonboots, you know i love your great answers! :D

no problem for the edit but I don't have the same result as you if I apply the scale, the ball simply fall on the cube, I'm not sure why it jumps up in your case?

really? i thought i just applied the scale....


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How do I disable the body mask on the Rain model?
I'm trying to learn a little Blender and I downloaded the Rain v2 model to experiment. It appears to be a fantastically well-outfitted model, however there's some basic stuff I don't understand. When I disable the scarf, for example, there's the body mesh underneath but when I disable the shoes, it appears as if there's nothing there even though I can see in edit mode that there's a full body mesh. Deleting the shoes doesn't make any difference.
Is the hidden part masked somehow, or hidden? How do I disable this?

TLDR
With the armature selected, in the CloudRig panel, under Outfits, you can choose if you want to mask or display the legs and arms. This is shown in the walktrough video at 1:00.
How it is done
The object "GEO-rain_body" has a Mask modifier (the 3rd one in the modifier pile). It masks every vertex belonging to the "mask_modifier" vertex group.
The two modifiers above, "mask_arms" and "mask_legs", add those respective vertex groups to "mask_modifier" ; but only in Viewport, not in Render.
Then things become a little bit more complex, because their visibility in viewport is driven (that's why the icon appears purple) by the value of a custom propertie of the armature. So, you just need to modify that property in the CloudRig panel, with the armature selected (so you don't need to select the object, go to modifiers and manually unset them).

Thanks @thibsert! The mask modifiers under GEO-rain_body did the trick indeed.


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Mesh modification
When I add a UV sphere and try to modify the segments, rings, radius or any other changes the drop down menu just disappear and I'm left with 32 segments and 16 rings. What am I doing wrong?

this menu only appears when an pbject is newly added. You cannot (unfortunately) reopen it later.

Hello :). If the menu disappears, you can use F9 key to bring it up.

As soon as I click on the menu it disappears. I was able to use the modeling tab and that worked for the sphere. However, I added a cylinder and the menu just disappears.


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Texture Paint: Color shows different on the mesh
I just started painting a mesh and for a while it worked OK, but now when I paint on the UV map, the color doesn't show as I chose.
Before:

After I painted on the door:

Can you share the blend file?

No, I don't press CTRL. Here's the blend file:

Try changing the viewport shading type to Material.


text:
2 and 3 key not working any more in 4.0.2 in edit mode

Blender 4.0.2
Keyboard typematrix
Layout bépo

2 and 3 key doesn’t work any more in Edit Mode
and no more special character is allowed (f. ex. by renaming objects)
in Preferences > Key Bindings, 2 and 3 key aren’t recognized any more.
Do you know what the problem is?


text:
How to snap 2D cursor to vertex in UV editor?
I'm in the UV Editor and I've UV-projected my object there. Now I want to move the 2D cursor to snap to any vertex of that object.
How to do it properly? I tried to turn on snap and set snap to vertex, but when I drag the 2D cursor, it won't snap at all. Snap to increment (grid) is working fine, but snap to vertex is not working . Any idea ?

Hello :). I'm afraid snapping in UV editor is still somewhat lacking. No absolute snap to grid and no snapping cursor to vertices.

But improvements have been suggested here on devtalk and here on rightclickselect

And no 'Active' element, either, which kind of breaks the grammar you get used to in the rest of the system.


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How should I make a round 'bevel object' follow my pyramid with no faces?
First time using Blender so my understanding of how it works might be off.
What I'm trying to make top left, how I'm approaching the issue top right - result bottom left

So I'm trying to make a shape that consists of two pyramid, on smaller flipped upside-down on top of the other. I want it with no surfaces, but a thickness in form of a circle.
While I expected the edges to be sharp at first try, I also expected a more "symmetric" result.

Why does the circular bevel tends to increase in size from edge-to-edge?
Is it a "one click" option to tell Blender that I want this wire-object (top right in my image) to have a circular thickness in a more elegant way that what I'm doing?
Is it a way to make the corners join elegantly with a sharp 90-degree angle when beveling or should I have smooth corners in the wireframe as well?

Possible duplicate of How to make beveled 90 degree corners on a curve better?

Thanks, read this and it does help me with promlem 3 - thanks!

Try this, it does not produce exactly what you want, but maybe good enough. Add a Wireframe Modifier to your double pyramid then a SubSurf Modifier set to Simple and 2 subdivisions and then add another SubSurf Modifier set to Catmull-Clark and 4 subdivisions.

Thanks Rob - exciting idea and certainly a lot closer! It is now a lot rounder and "friendlier" in the shape. But the exact numbers you gave me resulted in a very thin frame - possible to add thickness?

UPDATE: I added a Soldify modifier, this helped with the thickness! I has a lot of weird artefacts/geometry, but I'm very close to my vision now. :D


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What is the optimal topology for a base with square corner meeting a cylinder?
I would like to make this part:

This is my approach:

In order for the inner edge loops not go all the way to the cylinder, I cut the quad into two triangles. Like this:

But after adding loop cuts, the model still suffers from some pinching.

How can I fix this shading issue? And what is the optimal topology for this shape?
This is my blend file if necessary: Blend File

This topology seems to work fine, no visible pinching if you move the vertex a bit:

Lol this is like magic. I spend a great deal of time pulling vertices around but still got the pinching. Thank you! I'll try this.

I tried this way and still got pinching. Why does your model look so clean? Did you use my mesh or you created from scratch? Also, how do you deal with the problem that the inner support loop goes all the way to top of the cylinder? I see you join the two triangles.

I created it from scratch. Not sure about what you mean in your second question. I've edited my answer and linked my file, tell me if it's ok

Thank you for your kindness. I would like to ask about this: https://ibb.co/QrBX38Q. How did you create the selected support loop? One of my original problem is that when I try to create the loop, it goes all the way to the cylinder, just like the red lines. That's why I had to cut the two quads into 4 triangles to stop it from continuing, which partly causes the pinching.

You can create additional edges with the knife tool (K to activate, C to cut perpendicularly, Z to cut through), then to make it parallel to another edge, press GG to slide, then E to make it parallel to the next edge (press F after E to make it parallel to the other edge).

I got it. Thank you!

I would use a topology like the following to achieve a smooth transition between the rectangular base and the cylinder.

Wow, thank you! Very clean, rjg.

Hi, what about the problem that the inner loop goes all the way to the top of the cylinder? (that's why I cut the quads into two triangles) Is it a good practice to allow the square edges to have only one possible support loop?

@ĐặngHảiPhụng it's certainly not wrong to only have one loop between the base and the cylinder. It depends on how sharp you want the edge to be. Triangles should be avoided because they can cause the pinch you were experiencing. The difficulty here is, if you want to add another loop you need to adjust the cylinder because otherwise the distribution of the vertices is uneven. You could add your loop cut with CTRL + R and the use the Loop Tools add-on to evenly space each edge loop of the cylinder and correct the rotation afterwards.

Yup. Another problem is that the loop cut will go all the way to the top of the cylinder, which is why I had to cut the quads into two triangles in my model. I illustrate this issue here, with your model: https://ibb.co/LZW6hPM. May I ask for your approach to solving this?

@ĐặngHảiPhụng Yes, as I said you could use the Loop-Tools add-on. For each loop of the cylinder use Space to evenly distribute them in a circle. Repeat that for every edge loop in the cylinder and adjust the rotation of each edge loop along the Z-axis (Space distributes the vertices evenly but the edge loops may have a different Z-rotation to each other). Alternatively you can simply replace the cylinder part with a new cylinder that has the appropriate number of vertices and connect that to the base. The latter is likely faster for this particular case.

I got it. Thank you for your time, rjg!


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Is it possible to animate domain in mantaflow simulation?
I want to animate the movement of a cube (domain) with water like here: youtube, but the water sticks to the bottom of cube (domain).

If i try to use an effector as a cube the water just goes through it...
Is it possible to do this?


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Transparent Coffee Cup with Color Volume Makes Strange Objects
I'm following the Blender Guru beginners tutorial, and as I was making the coffee in the cup, it looked alright until you look at it from the side, where you see that it has all of these weird particles.
How do I get rid of these?
Blend File

Please use this tool to upload your .blend file: https://blend-exchange.giantcowfilms.com/ - More importantly, can you post an image of the particles you're referring to?

There is a known blender issue with "liquids" in cups. Make sure the liquid mesh fully intersects the glass (as in the boundry of the mesh is inside the glass wall, not inside the empty space)


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imported avi is jerky after cycles render in 2.92 / material preview in viewport is smooth
edited: thx blunder
i am trying to import an existing AVI. with "import image as plane".
everything looks fine in the viewport.
but it looks jerky as hell in the final render. but its limited to the imported AVI. Everything else looks smooth.
it looks like he is rendering the same frame of the avi-slideshow for 6-7 frames in the final-render. and on frame 8 he continuous to render the avi with frame 8.
so the "frame-pattern" would look like (1,1,1,1,1,1,7,8,9) instead of (1,2,3,4,5,6,7,8,9) creating a "hick up / lag" every 20 to 30 frames - maybe.
Problem only occurs in cycles render (but i have to use cycles - eevee#s object emission shader doesnt light up textures of other objects - but this is mandatory for my project)
i tried to change the frame rate but have no idea what else i could try.
i'm very sorry for my broken english. and hope that someone who can help understand what i was writing.
thanks in advance and for all the other things i already have learned.

Hello and welcome! This is a Q&A site, not a classic forum like https://blenderartists.org/. You don't need to introduce yourself, just focus on the question...but nice to meet you :-)

Try using an image sequence instead of the avi. The avi has to be decoded for the viewport and the material so this can cause issues.

Nice, don´t know if that´s exactly what you meant but my workaround now is:
New project - Import the original avi through video sequencer and rendered it as image sequence (jpg).
switched to my project and import the rendered image sequence "as plane" and voilà.
now it is a bit laggy in the viewport. but at least the final render is smooth. thank you!


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How to rotate without deforming
I'm very new to blender so I decided to follow some tutorials and at a certain part a guy rotates a plank fine but when I do it the plank deforms, the shear tool and transform tool does the same, I've lost my entire day to this plank
tutorial I was using: https://youtu.be/zH_eZDWCnMg?t=630

hello, it's hard to guess what's happening, maybe link the tutorial you're talking about, show some screenshots, etc

By deform, do you mean it has got thicker and has not rotated around the middle?  It is unclear to me still what the issue is but you may want to check your origin is in the correct place.  Perhaps you could provide the blend file as there ae a lot of modifiers there that may be the problem.


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weird, white, glossy looking rendered view mode
I'm super new to Blender and I need some help. I've been following a youtube tutorial "how to make a donut" and everything was alright till the rendered view mode. I don't know why, but in rendered view mode my donut has a very weird, white, 'glossy' look. When I switch to any other mode, everything is fine, donut looks normal. I didn't do anything to solve the problem, because I have no idea what the problem is. I would really appreciate some help :)))
here's a foto for better understanding the problem

can you send the . blend file?

What kind of GPU do you have, and are your drivers up to date?

My first guess is that you have a light source (point, sun or something else) that is way too bright.
Try and lower your light sources while in rendering mode and see if anything happens. Normally, lights only affect rendering mode, so my guess is maybe you tweaked the lights in another mode, went too far, and now everything is too bright.


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How to see the shader preview?
In shader editor, how can I see the preview of the shader or any nodes without its being applied to objects? something like 'viewer' node in compositing editor. Right now if I have a lot of 'image texture' nodes in the shader editor, I can't really tell what it is until I connect to the shader network or I have to zoom into the node and check the file path then view it in an image editor? this is really slow. when I select the image texture node, should be a preview in the side panel or anywhere else to see the thumbnail. Any tips? is there any better way to do it?

Have you enabled the Node Wrangler Add-on? It is in the built-in set, in User Preferences.

yes, i can have the viewer node (wrangler) , but still it has to be applied to 3d object in the scene right ? can i throw that viewer output to the image editor ?

CTRL+SHIFT+Left Click will create a Node Wrangle Viewer node that is used in the Preview and the Render View. Does that work for you?

it will create a viewer node but not showing up in render view. i can only see it in 3d viewport.

Sounds like you are asking for ⌃ Ctrl + ⇧ Shift + LMB .
Click the final shader, whatever feeds Material Output, to go back to normal.


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What is This Issue Called & How To Solve it
I have downloaded this File from the Internet and it was in OBJ format, When I imported it in Blender, this is how it is showing completely broken, and I don't know how to fix it. Can anyone help me out!!
Blender Version: 2.93

Difficult to say with only a screenshot, probably precision errors? they happen if the model its very big, check the scales of the model, it's a character it should not pass the 2 meters in height
you can check that in 3D Viewport> N > Item > Dimensions

It's alpha sorting issues. Turn off backface culling or switch the blend mode in the material properties. Or switch to Cycles.

maybe try Properties panel > Object Data > Geometry Data > Clear Custom Split Normals Data?