text:
How to align wave texture perfectly?
Is it possible to align procedural wave texture in Cycles perfectly - say - vertically? Because when assigned to an object (in node editor), it's rotated ~45° or so...
I tried playing with mapping, but it's never perfect...
Sphere; loc, rot, scale applied; not unwrapped:

Node setup:

Ok, I'm years late to the party, but the reason the texture is rotated is because it's applying the mapping using the X, Y, and Z coordinates equally.  If you want to constrain it to a single axis, you can just use a "SeparateXYZ" node followed by a "CombineXYZ" node and only use the axes you want.  For example, as gandalf3 pointed out, if you want the texture aligned along the Z-axis, simply connect the Z output of the SeparateXYZ node to the Z input of the CombineXYZ node.

Likewise, if you want it to follow the X-axis, connect only the X output to the X input.  If you choose both Y and Z, your texture will be at a 45-degree angle because it's affected half by the Y coordinate, and half by the Z.  You can also think of it bisecting the axes you use.

That's why when you use X, Y, and Z all at once, it points at exactly the center between the X, Y, and Z axes.  You might think that's 45 degrees from each axis, but it's not.  Since the rotations are applied on top of each other, you get the "weird" values of 35, 45, and 90 degrees (look up Euler angles if you want more info). It's not a mystery once you understand the math (or at least how the math works).

Thank you for both your answer and your time, however I don't have time to test it. As soon as some people prove it's the right answer, I'll mark it accordingly :)

I managed to do this with this peculiar set of angles on the mapping node:

Rotations:
X: 35d
Y: 45d
Z: 90d

Weird... Looks like the default values are not totally random, but why those strange angles then? Isn't this a bug? :P

Answering this requires delving into the source, for which the hours is much too late :-P
Not sure you can call this a bug, but it's certainly not a feature!

I'm not sure why, but it appears the wave texture adds the X and Y components of its input coordinates. You can easily correct it feeding it coordinates with the X and Y subtracted:


text:
Transparency of Image Empties not working
I'm trying to setup my blueprints in Blender, and I've more or less achieved it, but the image empties are not displaying the pictures well.
Edit: I think this picture more clearly describes my problem

What is going on with the rendering?? It's like impossible architecture.

Can you add a picture of the front ortho? What exactly are you after? It looks like you have both empties' transparency enabled, that will make one empty always show through, depending on the selection.

@360ueck: I can't add a picture of the front as I don't have enough rep to do so. I'm trying to get them to work like in 3DS Max, as in if I view the setup from the front, I should see the front blueprint, and if I view from the back, I should see the back blueprint.

@cegaton: I tried, and didn't really like the background method. It's hard to get all the blueprints to align. Also, they don't have an alpha channel.

Try change the OpenGL clip-alpha user preference.

@Python Newbie I found that annoying when I first joined SE as well. I think maybe 4 pictures would be a good minimum, not 2. I added an answer to your question, please take a look.

With no transparency level set, and all transparency options enabled (for all objects), blender defaults to complete transparency of all objects except the one selected, and behaves similar to x-ray.
To achieve the kind of transparency you'd like, follow these 2 steps:
1) Set a transparency level in properties> data (here I've set both images to 0.35).

2) Enable transparency in properties> object.

Playing with the Transparency option, I've found it works exactly like X-Ray: The object that has transparency checked in the objects property panel will always show. I've found that disabling transparency for the top and side blueprints, and enabling it for the front works best, but I still cannot get blender to display the rear blueprint when I am viewing the model from the rear. It always displays the front blueprint, even when I disable transparency for everything and have nothing selected.

@PythonNewbie Did you try setting transparency to 0.34 (for every object) in data? (Step 1). If you don't, one object will always act as x-ray, since the default transparency value is 1 (opaque). The reason your work around is working is because when you enable transparency without setting a value, you are essentially making the object opaque. Which is fine, but when transparency is enabled on at least one other object, it behaves as x-ray (not transparency). I'm sure the physics is relatively correct, but it's not what your looking for; which is why your having to work around it.

Yes I did, and it's still showing only one image both front and back view. I guess this is just a limitation of Blender's, although I have NO IDEA why it happens. 3DS Max was so much easier =P

The answer is here for the new UI https://blender.stackexchange.com/questions/159363/how-do-you-fix-opacity-to-a-reference-image-in-blender-2-81

source: Stack Exchange

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

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

sort: votes


text:
How to extrude inwards without leaving faces?
Here is the image to explain what i want

left box shows how i have set loopcuts (green is the face that i am extruding and moving). Middle one is what i want to get. The right is the issue with blender. the red faces will remain. (i have removed doubles on those faces) So is it possible to extrude inwards so that you dont have those faces hanging ? I know i could just delete those faces and thats it. but if you have lot of elements with similar idea it will get time consuming.  Thanks

Follow these steps
1) Go on Face select

2) Select the faces you want to "block" and click on Offset Edge slide

In this way these 2 faces will be indipendent from the others
3) Move your middle face in the position you prefer. Remember: move it, not extrude.

4) Select all your mesh and press w --> Remove doubles

Glad to help! Good night ;)

That's why I love this site. No matter how long you learn Blender there are still some cool tricks you haven't discovered by yourself. Thanks for sharing!

Glad to help mate! I love this feature too ^^

Also, extruding in vertex select mode works without leaving the unwanted faces.

I have a 'little black book' filled with gems picked up from this site.  This ans has just been added to it...  My thanks to @Fuboski, along with countless others.

I found the solution by checking the box on the Dissolve Orthogonal Edges option on bottom left box Extrude Region and Move.

Duplicated cubes, extruded, on the left with option checked, right one without

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


text:
Import 3D model from CityEngine into Blender and edit UV Map
I really would like to learn about UV mapping and I presume this is the best community for me to ask about Blender. I have a 3D building model produced from CityEngine and when it was exported into collada (.dae file) -or even .obj file- all its textures are stored in one folder. I mean, there are alot of images stored. I was searching for a means to merge these images into one image file and I have this UV mapping researched. I would like to ask how would I do that in blender. Can somebody help me edit my model and have the UV mapping in blender? I don't know where to start, I have importd my model into blender yet none of the textures were displayed. it's all white. I really appreciate help from you nad God bless.

Are you using Blender Render or Cycles Render?

I'm sorry Sir i don't know about that. .I am new to Blender. . I was not able to explore further about Blender. the only thing I have gone so far is to load my 3D building into Blender, that's all. .

Related: http://blender.stackexchange.com/a/7921/599

@King635, in my view, your project UV mapping an imported model from CityEngine, in Blender is like deciding to learn woodworking, and using this table as your first project. As I would advise you to choose another, less demanding project while learning to use the tools of woodworking, I suggest gaining facility with the tools in the Blender "toolbox" before tackling the UV mapping of the import. A good place to start this is the online courses under learning in question 15355

It might be useful to those who might wish to help you more completely, to upload a copy of your blend file to Blend-exchange, and post a link in your question so that those inclined to try to help could access the blend file causing your confusion. Exactly what the best way to combine the images into a smaller number will depend exactly on details of the images themselves.

To UV Unwrap your model, Go to Edit mode of your object and select all the mesh, then press U on your keyboard to open UV Mapping options and select smart UV project,

after change your window mode to UV mapping,

and finally open the texture you want to give to your object in the bottom bar,

once you opened you can scale and move your UV map untill it matches your texture how you want it.To scale press S key, to move press G key

I have already textures on my model. do these textures automatically mapped on its corresponding UV or there is a need for me to apply textures again . . Honestly, when I load my 3Dmodel into blender, these textures doesn't appear.

you have to open your own textures, I just gave an example of a texture, also opening texture in UV will not really give your object a texture, you have to go to materials tab in properties panel to apply a texture


text:
Render farm and blender
I am tried to render a scene using a render farm service.  When I send the file the system tries to render by using the command line and Blender (2.76b).  The farm uses nodes with no GPU/OpenGL etc...
Blender reports: "failed to read blend file…incomplete" although the same file reads in blender when opened with the Blender GUI app.
Has anyone else had this issue?  I am using 2.77a to create the files.  Reopening and saving in 2.76b and re-running on farm has been tried already.

This seems to have been resolved by unpacking textures and including them as separate files. Weird.


text:
Smoke domain causes artefacts in non-density areas
I get strange artefacts from the smoke domain where density should be zero but the domain box is over other collision objects in cycles (Blender 2.92 and 2.93 beta).  Res seems high enough.  For some reason, it seems to be caused by reflected rays of textured surfaces that are inside the smoke domain box.
I'm not sure what causes this to happen but I am trying to find a way around this.  If I disable the material input node, it goes away.  If I render with no smoke the objects are ok.  So the domain seems to affect the non-smoke area.  Any ideas?

Please [Edit] your question to include additional details and screenshots. As it stands I don't think there is enough information to be able to provide a meaningful answer.

I think I might have to render the image twice, once with and once without then combine in a graphics editor.

If you do need to render twice and combine the images you can use different Render Layers within Blender and combine in the Compositor within Blender. This is needed for certain situations and results. However, in your case, check that your Domain geometry doesn't exactly coincide with another mesh (whether another domain or volume or transparent surface). If it does exactly coinside, move it very slightly so that it does not. This might help since if surfaces exactly coincide in space it can cause problems with rays as they pass through that surface as Blender can't always tell when it does

I thought maybe the auto smoothing with weighted normals might be causing an issue but it did not.  I thought that trying a much higher res on the domain might help but it did not.  The rendering, I have set two views so it renders one then renders the other.  I can then combine after.  Because I need the smoke I might have to blend both layers in a graphics program.  It's just easier to get the areas I want.  It is a shame that the domain is causing the distortion as it would be nice to only have to render one view layer.

Note, that the artefacts seem to be linked to reflected textures through the smoke domain.  I don't know the specific relevance in the code, and I doubt I would easily tracking it myself.  I've not looked at the source code but it must have lots of crazy physics stuff.

Perhaps it's just a case of a really high res like 500 or something.

I have set up different render layers with mist and object indexes setup.  The mixing is looking good.  It will take approx twice the render time but sometimes this can't be avoided.

Without a screenshot it's hard to tell, but I often see artifacts in smoke simulations even in tutorials because of too low transparency settings. Try to increase the Transparency value under Render Settings > Light Paths > Max Bounces. Maybe 32 or 64 or even 128. Important: Transparency, not Transmission (image is from a different question, the red framed part is important).

I have 'full global illumination set'.  I'm thinking it might be a bug with the domain bounding box.  But I'm not sure.

How much bounces do you have for Transparency? I don't know the default values for full global illumination. I think my Blender has a default of 12, which is much too few usually. If setting it higher doesn't help, I can't tell what the real problem is without a screenshot of how it actually looks or a blend file to explore the settings.

Full global is 128 for each.  The smoke part is fine.  It comes out well it's just really weird artefacts on the other objects that should not have any smoke.  It looks almost like inverted normals on some of the verts but the normals are fine.

I'm sorry, I can hardly recognize anything in those screenshots... I don't see any objects, just an off-white blur which admittedly is not the same left and right. But it seems I don't know what's going on.

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


text:
Cycles renders a random alternate perspective
I have a strange problem I cant find remedied here or anywhere online.
In the Eevee viewport (where I set my camera up) my meshes appear exactly as I intend to render them. When switching to Cycles however, the mesh randomly appears really far off in the BG (and there's that strange circle around my render port view).
See below.
Any thoughts?
My render set up can be seen in the work panel.
And please forgive the blurred appearance of my mesh - it's not my model and I'm not in a position to share it.

Looks like your camera is set to Fisheye Equisolid (a Panoramic lens type in settings). Since Eevee doesn't yet support this lens type, it reverts to the standard perspective projection.

@HISEROD that is an answer, and appears correct.

@HISEROD - Thank you, mate. Wonderful to have your insight. Thank you!


text:
Adapt a 'buffer hack' .blend for 3.5.0-geometry-nodes-simulation
This question is address to to those who already use 3.5.0-geometry-nodes-simulation.
I have made this .blend based on the “buffer hack” and I would like to know how to adapt it for this experimental version of blender. There is no tutorials I can find about this version so if you have any addresses they are welcome to. Thanks a lot.

@Timaroberts Thanks for the Edit.

Just delete the pong node and use this node setup:

Thank a lot Chris, I new it was easy, but I cant figure out...

that's always that way. If you know it, it is easy. If you don't know - it seems impossible ;)


text:
Uv Badly Stretched
I am going through my first tutorials using blender and I am having a problem with the UV mapping that is not solved in my tutorial. Hence, I most likely did something wrong during the modelling but I don't know how to fix it yet.

This is the blade of a sword and as you can see it shows some heavy artifact that I cannot solve.
Already tried UV > Smart UV Project but nothing. Could anyone help by any chance?

Hello, does your object have any modifier ?

Please [edit] your question and add information on how you unwrapped the mesh. Also check that the scale of the object is applied before unwrapping.

@Gorgious yes it has subdivision and bevel

@susu I used only the Smart UV Project, nothing more

please show how your UV Editor looks like or even share your file (don't forget to pack your images): https://blend-exchange.giantcowfilms.com/

Smart UV Project is ok for example if you want to paint your object in the 3D view, but of course if you have a pre-made texture it will probably not match and you need to create seams then Unwrap > Unwrap


text:
How to get values of shape key with foreach_get?
I heard that using foreach_get is faster to get the values than using the normal way.
So I tried to get an array of shapekey values using the following method.
I selected the object that has the shapekey and ran it.
import bpy

context = bpy.context

ob = context.object
me = ob.data
sks = me.shape_keys

if sks:
    vals = []
    list = sks.key_blocks.foreach_get("value", vals)
    print(list)

However, Console just shows "None" and no values are retrieved.
How can I get the values correctly?

foreach_get fills the provided array with the values. It doesn't return anything. The array you pass needs to be the right length too.
    vals = [0.0] * len(sks.key_blocks)
    sks.key_blocks.foreach_get("value", vals)
    print(vals)


text:
Boolean modifier for 3d printing
I have a problem with custom dice for my 3d printer, when I print my numbers are all upside down.  On the other hand, the letters are all in the place, I followed at least 15 guide made 15 tried different and always the same result.  Basically I thought my problem came from my svg files, so I did everything in stl version, and still the same problem, so I made the numbers and letters in curve version and applied mesh to do the boolean operation.
Each dice seems to be perfect on the screen and when I put it in my slicer program, because I tried two slicer software too.  the result remains the same number coming from the inside, totally seems opposite to the model but the letters are ok.

enter image description here

I have make 100 test for sure, I created a 1d4 from a mesh, and from a math function, cut the top after having subdivide all top parts.
My issue seems to be the numbers each time I print after exporting the stl file, the the numbers are reversed but not the letter, I even try other fonts such as arial black, but nothing seem to change.
I check with 3d tool all ok, Its print pretty well, but like I said the number are always reversed. I'm on my last test reverse the number before apply boolean modifier and I'm waiting to see if it will work, but when I check in slicer file its seem to go well.
But like I said On the model everything seem fine but print number reverse , even when I switch side for the wrong side on model on slicer it seem so go right side of dice.

Hello, could you elaborate on your exact workflow when you export your object ? It's possible that the boolean objects you are using to cut the holes are still selected while exporting

when you say "reverse", do you mean that the numbers are indented into the die and you would like them to protude outside of the die ?

It might be helpful to people trying to help you if you uploaded an example blend file to the site https://blend-exchange.giantcowfilms.com/ and add that link in the question.

Hi , Thank again for respond, What is blend file ? and I got other image for better understanding if its help!

When you say reverse do you mean you want to extrude the text outward? Have you tried Prusaslicer? Do you have the original blender file before you applied the numbers with the modifier, If so upload that file (before applying any modifiers)? Or Is this an STL file that you imported into blender?


text:
How to find the rotation of one object relative to the local axes of another?
I have a series of objects that can be though of as a chain made of individual links. I am using a python script to place and orient these objects onto the surface of a mesh. This is working well.
Here is where I am stuck: I am trying to get the rotation of each 'link' relative to the previous links local axes in the same script. More specifically and in reference to the image below, the final output I am looking for is an XZY Euler that gives the rotations to get from object 1 to object 2 using the local axes of object 1. Said another way, I am looking for the local XZY rotations that will align the rotation of 1 with that of 2 without actually applying the rotation to the object.

My current thoughts are that I need to get the rotation matrix of object 1, then calculate a change of basis matrix to go back to the world coordinates (similar to clearing the rotation with Alt+R just without actually rotating the object in the 3d view). Then I can multiply this matrix by the rotation matrix of object 2 and convert that to an Euler since I don't know of a way to convert to an Euler using local axes.
Would this work, and is there an easier way to do this that I am missing?

Maybe I am missing something, but did you try (ob1.matrix_world.inverted() @ ob2.matrix_world).to_euler(...)

You're not missing anything, that does it! I had tried something similar before but I didn't realise that you use @ to multiply matrices. If you put this as an answer I will happily award the bounty.

To get the relative matrix of child in regards to parent do
mat_rel = parent.matrix_world.inverted() @ child.matrix_world

To convert a matrix's rotation to euler notation use to_euler.
euler_rel = mat_rel.to_euler('XYZ')


text:
Getting maximum value of shapekeys eval_time(python)?
Say, I have an object with multiple shapekeys on it.
Unchecking "relative" option gives me "evaluation time" parameter.
And the last shapekey has exact maximum value of the "evaluation time" parameter
How can I get this maximum value via python?

If the keys are absolute, rather than relative, they are maintained in sorted order, by time frame.  If you want to find the last key from the active object, use
bpy.context.active_object.data.shape_keys.key_blocks[-1]

to access the last shape key in the sequence.  It will be the one with the maximum value.  The field that contains the values is frame, so the maximum value will be found as
bpy.context.active_object.data.shape_keys.key_blocks[-1].frame

Obviously, you can replace bpy.context.active_object by whatever object you want to find the value for.


text:
"Mesh Boolean" output is unstable with driver

I'm using the version 3.0.1.
When I added a driver in any geometry nodes (e.g. #frame), I found that the result of "Mesh Boolean" node changes in every frames, even though the operated meshes don't depends on frame or any drivers.
It seems only changing the order of the vertices which generated on Boolean operation.
Is there any way to avoid this phenomenon?

i don't know whether this is still valid, but a few month ago the advice of one of the developers to me was: don't use the mesh boolean operator because it is slow and unstable. Use delete geometry instead.

Thanks Chris, that's interesting. But I cannot imagine how the Delete node will replace the Boolean operation.

If you have a „simple“ Boolean operation with a cube - it is simple vector math operation. Of course it is another case with more complicated geometry. But even there - it is „just math“ - but more complicated.

Just think of this: if you have a working function which returns a Boolean if a point is in a geometry or not - then you could build a Boolean modifier with this function.

I can't reproduce your issue. Just downloaded Blender 3.0.1 2022-01-25 17:19 hash dc2d180118171 Windows, geonodes setup: https://i.imgur.com/yW0nnsc.png , when playing the animation, nothing changes... BTW, getting an internal error when uploading to blend-exchange...

Thanks Markus for your testing.
Yes, while playing the animation I also cannot see any changes in the Viewer . When I'm stepping frame to frame by arrow keys, or using the index attribute of vertices in the Boolean mesh, this phenomenon is seen.
But, I should have tried also the vanilla 3.0 w/o any Addons. I'll try that.

I also don't see any change when stepping frame by frame using left/right arrow keys.

I installed the vanilla environment, and I could reproduce it in it too.
Don't you see only the vertices with the smaller indices?
It occurs on the vertices with the larger indices those it might be generated by Boolean node.

And, wow, it's not seen in the 3.1.0-beta !


text:
UV unwrapping behaves in a weird way
I made this sword (my first model without tutorials ever, so I might've made many dumb mistakes) and wanted to UV unwrap it. The problem is, when I unwrap, some parts of the mesh simply don't exist on the UV map (the crossguard, the other side of the blade, most likely some other things as well)
When I unwrap just the blade, it functions fine, and I end up with the blade properly split along the seams

Here's the sword's file itself: https://www96.zippyshare.com/v/e5uxa0TH/file.html
I think my main mistake was that I didn't make the whole sword out of one mesh, instead I created the blade, crossguard and the handle pieces separately and then joined them together using booleans, but it still doesn't make it clear as to what is wrong with the model

Try unwrapping a single face of the part that otherwise doesn't unwrap. If it unwraps, then press Ctrl + Numpad Add, to increase the selection, and try again. This way eventually you will discover where's the problem.

So, first off, no I would say your biggest mistake thus far has been trying to make the whole thing be one solid mesh. That's completely unnecessary, doesn't even translate to how the object is made in the real world, and makes your job 5x harder for no reason. Keep them all as separate objects and only join them if you absolutely have to for a specific purpose. Most props are composed of several if not hundreds of separate individual objects.
I also would not have applied all of the modifiers, this just makes unwrapping a bigger pain than it needs to be. You can apply stuff like SubDiv after the fact if you want, but at least apply the seams and unwrap it while it's still low-poly and then apply it after than. The UVs usually subdivide just fine.
Just consider how much easier it is to unwrap this:

Than something like this:

Using the Boolean modifier also just introduces all kinds of silly geometry all over the place like random slivers of triangles floating between the blade and the cross guard.

Those make getting clean UVs much harder as well. AFAIK making them mesh watertight like this is only necessary for 3d printing, which I can't imagine that's what you're doing if you're also trying to UV unwrap it.
So when I first open your file, I selected the parts I could see were unwrapped and hid thoses and then selected all of what remained, and you can see that it does have "UVs" right there in the corner. They were basically all set to 0. Which you might have had them unwrapped before they got joined but it's likely that using the boolean modifier would have erased all of that

I added a few more seams because IMO the ones you had were not sufficient to get a good unwrap and this is what I got.

Also I would recommend you scale your object to something closer to real-world scale. It just makes navigating around the object easier. right now you have a sword that is like 50 feet tall.

Thanks for answering! I made it one solid mesh because I thought that's what it had to be in order to even make the UV unwrapping possible (I wanted to texture the model in substance painter later on). As for the UVs being at 0, is there any reason for that? I still don't really understand why that happens

It probably has something to do with the boolean mod, I'm not sure on the whole backend but I'm pretty sure it is creating all new geometry from scratch in Bmesh, and that doesn't give it UVs afaik. Usually you  would prefer to keep the indiv objects in blender separate, give them matching names for the HP and LP, like "blade_low, blade_high, handle_low, handle_high", and then Substance has a feature that matches them to eachother during baking.

You want to keep them separate, generally in Blender, and then export them as FBX by selecting all the "sub-objects" and then exporting them as one combined FBX

>>>and you can see that it does have "UVs" right there in the corner.<<< - that's where the unwrapped UVs reside, at the default initialization of floats, 0.0.


text:
How can I update a Panel from an Operator?
I have an Operator that fetches some data on execute. I want to iterate the results, adding rows to the layout of a Panel. I'm stuck on how to give the Operator a reference to the Panel.
# ------------------------------------------------------------------------
#    Properties
# ------------------------------------------------------------------------
class MyProperties(PropertyGroup):
    my_category: EnumProperty(
        name="Categories:",
        description="Apply Data to attribute.",
        items=[ ('All', 'All', ''),
                ('Wood', 'Wood', ''),
                ('Fabric', 'Fabric', ''),
                ('Plaster', 'Plaster', ''),
               ],
        )

# ------------------------------------------------------------------------
#    Panel
# ------------------------------------------------------------------------
class OBJECT_PT_ResultsPanel(OBJECT_PT_AddOnPanel, Panel):
    bl_label = "Results"
    bl_idname = "OBJECT_PT_results_panel"
    bl_parent_id = "OBJECT_PT_addon_panel"

    def draw(self, context):
        layout = self.layout
        layout.label(text="Results go here...")

# ------------------------------------------------------------------------
#    Operator
# ------------------------------------------------------------------------
class WM_OT_MyOperator(Operator):
    bl_label = "Get Data"
    bl_idname = "wm.my_operator"

    def execute(self, context):
        scene = context.scene
        mytool = scene.my_tool

        recs = get_data_for_category(mytool.my_enum)
        # for each record, add rows to the results panel

        return {'FINISHED'}
```

You seem to be most of the way there.  Have the operator update the PropertyGroup with the data and have the panel layout display what you've added to the PropertyGroup.

Oh! That makes perfect sense and never occurred to me. I think now I'll need to learn how to make a JSON array into a custom property. Will try that now. Thank you!!

I struggled and never came up with a way to use a dict as a custom property in MyProperties. I was able to get the result I wanted using a similar approach. Instead, I attached the dict to context.scene['my_records'].

You should write up your final approach as an answer to your question and then when enough time has expired accept it, so people who find this in future will know what worked for you.  (If you do, I'll upvote both the question and the answer.)

After a lot of trial and failure, I have not been able to add a custom property to MyProperties that is a dictionary object. I still think it's possible and I'll keep trying. In the meantime, I was able to get the result I want using a similar approach to the one @Marty recommended. Instead, I attached the dictionary to context.scene['my_records']. Here's the snippet above updated to show what works:
# ------------------------------------------------------------------------
#    Properties
# ------------------------------------------------------------------------
class MyProperties(PropertyGroup):
    my_category: EnumProperty(
        name="Categories:",
        description="Apply Data to attribute.",
        items=[ ('All', 'All', ''),
                ('Wood', 'Wood', ''),
                ('Fabric', 'Fabric', ''),
                ('Plaster', 'Plaster', ''),
               ],
        )

# ------------------------------------------------------------------------
#    Panel
# ------------------------------------------------------------------------
class OBJECT_PT_ResultsPanel(OBJECT_PT_AddOnPanel, Panel):
    bl_label = "Results"
    bl_idname = "OBJECT_PT_results_panel"
    bl_parent_id = "OBJECT_PT_addon_panel"

    # don't draw until my_records exists
    @classmethod
    def poll(self,context):
        return context.scene['my_records'] is not None

    def draw(self, context):
        layout = self.layout
        scene = context.scene
        layoutRecs(layout, scene['my_records'])

# ------------------------------------------------------------------------
#    Operator
# ------------------------------------------------------------------------
class WM_OT_MyOperator(Operator):
    bl_label = "Get Data"
    bl_idname = "wm.my_operator"

    def execute(self, context):
        scene = context.scene
        mytool = scene.my_tool

        recs = get_data_for_category(mytool.my_enum)
        scene['my_records'] = recs

        return {'FINISHED'}


text:
Animation Nodes: How to unzip a list
While searching for an answer for this question here Exponential replication of object, I came across an issue which I think should be easy to solve, but somehow I'm either blocked or stubborn. I've created a nested list, which according to the Debug Output looks something like this:
[[(0,0,1), (0,0,2)], [(1,0,1), (1,0,2),....]]

So, format-wise it is a Generic List surrounding a bunch of Vector Lists. How can I unzip it (that's what it's called in Sverchok), meaning to get this:
[(0,0,1), (0,0,2), (1,0,1), (1,0,2),....]

Any help appreciated!

I'd suggest to use an expression or script node for that. Although an expression should be all you need. Only in case you need to do this in multiple places you should use a script node maybe.
a = [[(0,0,1), (0,0,2)], [(1,0,1), (1,0,2)]]

# long version (for script node maybe)
result = []
for sublist in a:
    result.extend(sublist)

# shorter version (single expression, can be used in the Expression node)
import itertools
result = list(itertools.chain.from_iterable(a))

# you can also use a nested list comprehension
result = [vector for vector in sublist for sublist in a]

To use itertools in the expression node you need to write that into the advanced node settings:


text:
Where do the white lines come from in my composite?
I'm having this issue for years now, and I'm not sure if I am doing something wrong on my end, or if what I would like to achieve - or expect to see - is even possible. My question is about compositing artifacts when using Blenders mask layers. Let me explain:

In the Blend file provided, there are two objects: Dragon A and B. Each of them is on a separate layer, rendered on a separate render layer, and masked with the other one. So A is masked out by B, and B is masked out by A. Like this:
scene setup

RenderLayers A and B

When I render, I write out two MultiLayer EXRs with 16bit depth. That Stuff, I feed into the following comp:

and it gives me this:

You can clearly see the white lines around the areas where the dragons mask each other.
If I comp in a weird fashion like this:

I get this:

It's not perfect, but still a lot better than the first one. What I am doing is kind of cutting off the bright alpha values, making a 0.75 alpha value equal 1.
My question is: Why do I see the white background shine through after all? Is it something which is fundamentally unchangeable and we have to live with? Am I doing something wrong on my side? Do you have an alternative solution?
Edit
The solution Ray Mairlot came up with solves the issue by only masking one of the two, the other one would exist un-masked underneath, and thus provides a perfect overlay. However, I'd like to still mask one against the other for specific reasons: I'm sending images to a web application, which layers them dynamically (a configurator in essence). There can be 30 or more image layers, each of them needs to be downloaded by the website visitor. If I could mask one part against the other, the individual file size would be smaller. Not really a necessary reason, but that's why the idea came up. The other reason is, if I mask the layers, the individual layers render faster. This can save me some 30% of the render time per configurator (which renders on average for 12 hours).

Did you try checking the "convert premultiply"  on the Alpha Over node??

@SamirRahamtalla I did, in this case it makes no difference. I also tried reordering the composition, so first the dragons would be comped, and then I'd comp against white background. No difference.

+1. This is a good question. A very good question. It is Specific and Clear. It shows what you've tried, what you think, and has useful images. I wish this site had more questions like this.

"Why do I see the white background shine through after all?" The back image can't block the background because it's masked by the front image. The front image is not fully opaque everywhere, so doesn't completely mask the background on its edge.

Those two images you're trying to composite together have "correlated" alphas. The Alpha over operation isn't the appropriate operation for this situation.
The solution is simple: you just have to add those images together, then add their alphas together and assign the resulting alpha to the result of the first addition.
Here's how:

Why alpha-over doesn't work
Alpha over is, like its name states, an "over" operation. Something is over something else, covering it. The alpha channel determines the occlusion of the background by the foreground.
When you inspect the alpha-over formula for two associated (premultiplied) images, you'll see it's just an addition, but before that addition the alpha channel of the foreground is inverted and multiplied on the background, casting a shadow on the pixels that the foreground occludes.
Associated Alpha Over Operation:
Foreground.RGB + ( ( 1.0 - Foreground.Alpha ) * Background.RGB )

Porter Duff Alpha Merge Operation Uncorrelated Geometry:
Alpha.A + Alpha.B - ( Alpha.A * Alpha.B )

Correlated Geometry:
Alpha.A + Alpha.B

When alphas are correlated, like in your example, there is no foreground-background situation. It's rather filling a hole in one image with the other image.
The hole and the image that will cover it fit perfectly, so there is no reason for casting a shadow on the background. There's already a hole in it.
If you use alpha over, the "shadow" of the foreground will be multiplied again on the antialias pixels that are already shadowed by the mask, causing a doubled value of transparency, and that's why you get those semi-transparent pixels where they should be completely opaque.
So, skipping the "over" part by just adding the two plates together works perfectly. In Blender you have to add alphas too and assign the result to the mix.

This works like a charm! Would you mind adding a reference to the Alpha Over formula you mention, or insert the formula directly into your answer? This way it might become clearer as of why this solution works, and the other one doesn't. Two years I've spent wondering about this issue, can't believe the solution is that simple...

I would add that thinking about it in terms of probability (remember that alpha in associated alpha imagery is geometry) that we can see A+B - (A*B) turns the latter half into 0 when the geometry "perfectly snaps together". Hence there is no cheating nor hacking here, but rather the same concept considered against the geometry of the original situation, slightly hidden in the fact that the rasterized pixel is blending the geometric result.

https://en.wikipedia.org/wiki/Alpha_compositing
Think of alpha channel as a model of emission and occlusion: an object in front of another adds its own light, but also occludes the light coming from the object behind.
When you perform an alpha-over operation, it has two parts:
it inverts the alpha and multiplies over the background, creating a holdout (that's the occlusion part)
Then the foreground is added (that's the emission part).
The latter is what we have to use in this case, just the added emission.

The alpha over formula for each pixel is: Co = Ca + Cb × (1−αa) for colour and αo = αa + αb × (1−αa) for alpha channel.

Another question related to this. https://blender.stackexchange.com/questions/75953/halo-border-in-masked-images Can this solution be extended to many render layers?

From what I can see, the error is that your original render layers from your 'Render' scene are set to mask each other out. I can't personally see a reason why you would mask them (particularly not both of them) if you are looking to combine them.
Disabling the masking on the renderlayers:

And using this node setup:

Gets this:

That's a very good advise, +1 for this. In the real world example, I'm sending images to a web application, which layers them dynamically (a configurator in essence). There can be 30 and more image layers, each of them needs to be downloaded by the user. If I could mask one part against the other, the individual file size would be smaller. Not a really necessary reason, but that's why the idea came up. The other reason is, if I mask the layers, the individual layers render faster. This can save me some 30% of the render time per configurator (which renders on average for 12 hours).

But the main reason is: I DON'T GET WHY IT SHOULDN'T WORK  :))

I don't really understand why it would work, but I don't have the knowledge to explain why. I imagine it is to do with each of the objects having partially transparent pixels at their edges leaving a transparent line inbetween them.

Also, I would suggest you add in to the original question that you need each layer to be masked by the other.

I've edited my question as you suggested. Meanwhile, I did some tests in Gimp. I'll try to replicate that tomorrow in Photoshop too, just to make sure, but if I get the same results on that simple test (not the dragons, something different), then you're most likely right: It's impossible.

You don't need two Aplha Over nodes. This way  it works:

Thanks for the answer, but the problem is: I need to see my comp against white, as the final output will be on a white backplate (studio shot). The white background was not added by accident.

I think the problem is in the render, because if I open them in Photoshop and layer them on top of each other there is the same issue.

I see the same issue, also when we comp in AfterEffects or Nuke. But why is it behaving like that? It might be that this effect we see is totally valid and makes sense (from a math point of view), but I haven't been able to figure out why.

The problem is that you're overlaying the silver dragon with a white background, before you overlay it on the orange dragon. Just use one alpha-over. One image with an alpha channel goes into one slot and gets overlayed onto another image which goes into the other slot, instead of the white color.

Thanks for the answer, but the problem is: I need to see my comp against white, as the final output will be on a white backplate (studio shot). The white background was not added by accident.

not sure why this has been downvoted, thanks for the answer still

(I'm not sure either... oh well) In that case, you should add the white back plate last. Use one alpha-over to combine the two images, then use another alpha over to put the image over the white.

I've tried that already, makes no difference. The answer which Gez gave however is absolutely correct. It has to do with the way alpha operations are mathematically defined, and Alpha Over in my case was simply a no-go.

Interesting... Glad you got it sorted, anyhow.


text:
How to select all related objects?
For example,
there is cube that have boolean modifier with sphere object and sphere object also have union boolean with torus,
and the cube also mirrored with empty object as origin.

The question is, how do I select the whole related object on the cube quickly?
Is there anyway to do it automatically? A script or add-on is fine.
Addtional info:
If you only select the cube then copy it by pressing ⌃ Ctrl + C the whole related objects will also copied.
Then, if you paste ⌃ Ctrl + V the whole objects will automatically be selected, this selection method is what I meant.
Download .blend file

This is a bit of a programming recursion problem to implement, and a bit of a rightclickselect.com request to ask about here. To trace through all the modifiers and constraints could cause trouble in large or recursive systems.

Thanks for your suggestion, if this select feature it not already on blender, i hope someone can share the script here

I don't think you're going to get a complete script for this, and no the function doesn't exist in Blender by default.
The basic function is easy to design and here it is in pseudocode:
examined = set()
to_examine = [bpy.context.active_object]

while to_examine:

    object = to_examine[0]
    to_examine.remove(object)

    for new_object in EACH_OBJECT_RELATED_TO_OBJECT:
        if not new_object in examined:
            to_examine.append(new_object)

for object in examined:
    object.select_set(True)

This is a common pattern when you are walking a tree but only need to know the names of the nodes.  Every time it encounters an object it hasn't seen before, it adds it to the list of objects it needs to process (to_examine).  Whenever it wants to process an object it removes it from that list.
Each time it finishes processing an object it remembers the object by adding it to the examined set.
At the end, every object that is related to the original object is in the examined set.
The real problem is EACH_OBJECT_RELATED_TO_OBJECT.  You need to evaluate every aspect of the original object, like parenting, children, modifiers, et cetera, to see if that aspect turns up an object.
But that code is tedious to write, and very fragile.  For instance, here's a tiny fragment of code to find the objects related because they're in a modifier:
def get_modifier_object(modifier):
    if modifier.type == 'BOOLEAN':
        return modifier.object
    if modifier.type == 'MIRROR':
        return modifier.mirror_object
    return None

That happens to handle the two modifiers in your object, but to be complete, there needs to be an if for every modifier type, that either does nothing, because the modifier doesn't use another object, or returns the modifier's object, and every modifier that has an object identifies it through a different property.
So the final script would be full of functions to identify modifiers by type, constraints by type, et cetera and return any objects used by those pieces.


text:
glitter/sparkle effect on hair
I saw a couple of pictures and renders on Instagram lately where mostly the hair is sparkling and very glossy on spots where the light is. I’m new to blender and I tried to add glare in composition but it didn’t do anything.
I tried to max out the glossy slider on the rig itself but it doesn’t do anything. how to get it to shine like this? Is it the light source? or the rig/hair itself? (the image is not mine)

I added the shaders and suggested by BlenderMaster15 and it came out like this:  how do I get rid of this? The texture is corrupted or something? (the "cube" fragments in the hair)

Is this particle hair or hair cards (textured planes)?

For that glitter effect, try adding a really small noise texture to the hair's roughness socket, and add a colorramp node to the noise texture. This way, you can control how small the glitter is.


text:
Transparent Alpha textures and Freestyle rendering
(Using version 2.83)
When I use Transparent alpha and render image with Freestyle it keeps rendering transparent Edges and are visible, how do I make them invisible?

You can disable render object outline , but it disables for whole render. Why do you need freestyle?

Yes that's true, Freestyle is one of the technique I render my images with.

Does this answer your question? In blender 2.9 how do I get freestyle to ignore transparent materials on a vroid character

Move all objects that shouldn't have freestyle outlines to a new collection (you can select them, press M and create a new collection or choose an existing one). Then, in View Layer tab, inside Freestyle section, select the freestyle condition to also be based on a collection - then precise the new collection and choose exclusive to not draw over objects from that collection.

Hi Markus, thank you very much, it works, amazing thanks again.


text:
Adding outlines to hair particles?
I'm trying to reach a flat cartoony look for my character but when I use any sort of option for cel shading it will never outline the hair particles, is it even possible? Could I somehow make a special shader to achieve that? The shadows are part of the texture.

Blender's Freestyle doesn't work for you?

nope, it only outlines the base mesh

Sorry, worked in 2.79 for blender internal https://imgur.com/v2p44Ty ... what result do you expect ... do you have some reference? Get outline for every strand it became totally black or are you asking for silhouette of character including hairs? Anyway usually hairs for anime are done via polygons even they use curve thickness.

I was looking for a silhouette of the fur along with an outline of the model, for example if i draw over this image i'd want it to look like this, https://imgur.com/a/TfYDwOs  the second image is an example taken from Beastars, they don't use blender but they have particle fur and are using some sort of custom shader maybe? i was trying to emulate that effect

For silhouette outline is usually used Freestyle, but it is not working with Hairs. Since Freestyle is post process effect anyway, there is even probably faster to use Compositor to calculate this effect.

You can try some node tree based on object separation - like Index OB or Cryptomatte and create outline with Sobel, InPaint, Dilate-Erode kind nodes.
Option 01
For few objects you can arrange it with Index OB node and Sobel node to generate outline.

Option 02
For more complex scene Cryptomatte works better, since you can generate outlines for all objects at once from Pick output directly. You don't need to select them one by one ... just reuse random colors of Pick output.

Note: Sometimes Filter node (like Sobel, Perwitt, ... type) generates from Cryptomatte's white color filled place, Increasing Fac over 1 fix that. I would say it is because Cryptomatte's Pick colors represents more dynamic range than Filter node can handle. Using this socket directly is not proper way of using it, it is more a hack so that is why I had to use Math (Greater Than) node because direct use handled white color in a wrong way again. Greater Than node clamps high values.


text:
Is it possible to apply Geometry nodes?
I have used geometry nodes to scatter objects at the vertices of a plane. I'd now like to apply this so it becomes a mesh and then I can export it into other software. Is this possible in 2.92 or any of the experimental builds?

You would think that using the 'Apply' action of the Geometry Nodes modifier would apply the changes... however, this simply seems to remove the modifier without changing the geometry. Since Geometry Nodes is still under development it would seem likely that that particular functionality has not yet been developed.

It does not work in 2.92 but I believe it works in 2.93

I downloaded the most recent daily build of 2.93 and that still didn't seem to work.

Yeah same here. I was able to recreate the same effect with particles and convert to mesh, but it's not quite as simple of a solution.

Not sure if this is what you need, but "make instances real" is one way, but is going to be a mesh per object

That is exactly what I need - thanks very much Amir.

The issue with Realize Instances is that the object will lose some data during the process, like vertex color, and I don't understand why...

If It's Blender 3.0 use the node Realize Instances, then apply the modifier. The  Realize Instances node basically converts the geometry nodes into real geo.

It's also very helpful, when you need to add other modifiers AFTER Geometry Nodes, which won't work otherwise

If my scattered objects aren't real, then what are they? I don't understand what this node does.

Thank you!  Possibly the most useful geometry nodes information I've run into yet!  (Also works in Blender 4, BTW.)

you can just use the "realize instances" node which will make the instances "real" and they will be a part of your mesh after applying the modifier.
More info: https://youtu.be/VynJrxedBuQ
(1 min)


text:
Bone is deforming vertexes but shouldn't
I prepared descriptions on the photos:

Vertices are assigned well:

What I would like to achieve is to move whole arm with keeping constant distances between vertices.
I assigned only blue vertices, made minimum and maximum scale to 1.
I tried to turn off deforming but arm didn't track bone then.
I tried some other options but it was only random shots, I knew they shouldn't work.
File to download:

I solved this issue:

These 4 vertexes was added to the previous (selected) bone and it made a problem!
I removed them from selected bone and problem disappeared. I think I don't understand this system yet.

You have to assign the vertices in the vertex group of that bone to adjust which vertices to be deformed by the bone, not a limit scale.
Do this, select the armature and SHFT+Select the mesh making sure that the mesh is the active object. Then go to edit mode, and on the right properties panel go to the vertex groups tab, and select the vertex group assigned to the bone of the character's arm. It should have the name of the bone.
Make sure no vertices are selected before selecting any vertex groups by pressing A once. Then select the vertex group for the bone.
The vertices assigned to that bone should appear. If some are showing up that you do not want to deform from that bone, deselect them.
After this, press CTRL+I to select inverse, and then press "Remove". This will then remove the vertices selected from that vertex group, so that they don't deform with that bone.
EDIT:
So I found the issue to be that you have an unnecessary bone in between the arm and the shoulder. By deleting this bone, the arm deforms properly.

Now the arm deforms properly:

Thanks but I have written that vertices are assigned well. I edited my post and added screen with proof.

If you are willing could you add the file?

Ok, I added link to my google disc. It shouldn't disappear until Google is existing.

Ok, I solved issue. This arm bone has correct vertices. But previous bone didn't!
I contained also 4 selected (in my post in last screen) vertexes.
I didn't moved this bone but it was interfered with arm vertexes in any not know way for me.
Thanks for you advices, without them I wouldn't notice this.
Maybe you could write my solution so I could make your post as answer?
You can use my screenshot. Just write that previous bone is influencing this arm :-)


text:
Shouldn't Blender free the GPU memory before rendering the next frame?
I'm trying to render an animation, I can provide the .blend if necessary.
The problem is that if I render each frame as if it was a single render, it works fine. However, if I render it as an animation (multiple frames) I get OutOfMemory error when it reaches a certain frame (which I can render fine if I render just that single frame).
I'm monitoring the GPU memory usage and it seems that the memory used in one frame is not being freed after the render is done. Is this the default behavior? If yes, is there a reason for it? If not, what could be causing it?
I'm using Blender 2.77 on Windows 10. My GPU is Nvidia's 980TI.
EDIT
I found the actual problem. It was an add-on that supposedely shouldn't do anything related to rendering. It's called Perfect Shape. I disabled it and all renders worked fine, motion blur or not.

You might want to report this to the devs

@cegaton I think you nailed it. I wasn't supposed to be using motion blur for this piece but it was turned on. I turned it off and now the rendering is working fine.
Although now I'm not sure this should be the case even with motion blur, This report seems to suggest it shouldn't increase the memory usage like it is. Apparently it should have been solved around 2.66. I'll try resetting the settings anyway

Indeed, this appears to be a known bug with that addon. If you'd care to add an answer (since you discovered the cause), go ahead :) If not, I can.

Might be a bug or a memory leak.
Blender does free unneeded memory as efficiently as it can, whoever it probably doesn't flush all memory when rendering an animation, as that would be highly inefficient.
There are immutable things that don't change between frames like geometry, materials, texture data, etc. and re-sending that unchanged data to the GPU every single frame would be a very big waste of time and resources and be very inefficient.
As such Blender tries it's best to be smart about it and keep as much relevant information in memory as it can. That being said memory management is probably a very hard task to do efficiently, and many times unneeded things are erroneously left behind. It's what I believe is called a memory leak (I'm not a programmer, I am hoping someone more enlightened in the matter than me will clarify or correct me here)
Over the course of rendering several frames those things build up and cause memory to reach it's limit.
That can probably be considered a bug and might be worth reporting to the tracker, I think. Although the chances of solving it are probably slim.
let's see what other have to say about it

I have the same problem. When rendering a single image Cycles used 1.2 gigs of memory and did not free that memory when finished. I then rendered the image again and Cycles just added more memory on top of the 1.2 gigs and bumped it 1.5 gigs. Did this a couple of times and made it to 2 gigs of memory still being allocated after the single image render was finished. I have radeon r7 360 gpu and at this point I can not render out any full animations without running out of memory. In fact my entire system crashed several times. I am using Blender 2.78 with 8 gig ram and 2 gig gpu with a 12 gig cache. The problem is Cycles is not clearing memory after the render.

Update: Under Performance I set Dynamic BVH to Static and unchecked ' Use Hair BVH' and this seems to stop all the memory usage. The memory stayed under 600 meg for the single image. I will try an Animation to see what happens.( The single image was 1920x1080 and samples 200 with only 4K verts in the object)

This doesn't happen for me with a GTX 460 (CUDA) on Linux. OpenCL support is relatively new and unstable, so it is very likely a bug. I'd submit a report and see what the devs think.


text:
How can I make a separated piece of my mesh not move while i'm proportionally editing another piece?
I am editing mesh that has separate pieces but I want want to use proportional editing at a certain thresh hold to edit my mesh, but when I do, other pieces near it (that are not connected) move. What can I do so they won't move?

Try ALT+O to change proportional editing to Connected

I always wondered what that meant, thank-you

@Denis no it's not the same question because that question is asking for the shortcut, i was asking for the actual function. I didnt know what connected was before so i would not been able to ask that question

Related http://blender.stackexchange.com/questions/36146/is-there-a-way-to-do-proportional-editing-only-on-specific-vertices

@Mr Zak yeah that question is very similar

@Denis Put your answer as an answer not a comment.


text:
Need help with manipulating center points!
I have an object which is formed of different layers of mesh. I want to show it open up , with smooth animation, and then close again. I have tried what some people suggested on here before, which was to use manipulate center points and scale. However i get a little problem with this, which you can see in the image. If anyone knows how to fix this, i'd be really happy :)

As @R00t suggested, it's hard to help without the .blend. If you can, can you upload it using blend-exchange.giantcowfilms.com and edit your question with the link? Thanks!

Driver controls Delta Transformation Location X value

The red object location relative the to yellow object location controls the final locations of the blue planes via a driver.  The red object is useful for the Blender python script driver described below.
A red delta mesh object controls the Blender Object [Delta Transformation] Location X value of the two flanking light and dark blue planes relative to the yellow middle plane.  A Delta Transformation Location value is added to the regular Location value to see a final location on the screen.  Simple Addition.  A python script driver allows us to use the distance between the red cube and yellow plane to offset the blue flanking planes.  The red cube can be animated. Multiple locations for the the red cube and controlled movements of flanking planes are shown in the animated .gif file above.

Many of the images below are composed from multiple Blender screen captures to reduce time, produce single size images.  Keep that in mind when inspecting the images.  Click on images below for larger version and to read the text.
Flanking planes final placement is controlled by red object. Outliner windows shows objects involved. Composed image above emphasized by black divider.

Flanking Planes left and right.  The tool tip on the Delta Transform X Location show a simple python formula.  The purple coloring of the value and the tool tip indicate a python script driver is used.  Add Single Driver was selected  from value pop-up menu.

The driver windows show the driver values for the moving planes.  The arrows indicate the Graph Window and the Editing context. A Composed image to compare formulas .... emphasized with black areas.  Click image to see larger view.
You must select one plane and add a driver.  Then you must select the second place and add a driver.
The two simple names and text formulas you must type into the respective windows below and are visible in the screen capture as well.
(delta - middle) ... and ... -(delta-middle)
All other values come from the menus.
Simplified sequence of steps.  Inspect and Improve.
This proposed answer is not a tutorial for beginners.
Please search [Blender Driver Tutorials] and you will find many matches for free on the famous video website.  If you need a tutorial see a video tutorial, this is an efficient use of time.  Many videos will show you how to create a driver in general.
A recent video on Blender Driver Tutorials on a video website will provide a better visual tutorial.  The video will not have the simple formulas stated below. Video tutorials often work better than text tutorials for Blender.  Recommended for people who state they are beginners.   You can even search here at BSE with the keywords provided.  I am sure I and many others here at BSE learned about drivers by searching on the very famous video website. This is not intended as a tutorial on drivers in general.  This site has claimed not to be about tutorials.
The 4 objects placement is indicated above. Red cube is controller. 3 planes have initial separation.  Select a flanking blue plane.  Locate and Know the Delta Transformation values are listed below the regular Transformation values.  I am using the X location for this example.  Mouse over Delta Transformation X value, alternative mouse click brings up the menu indicated above.
Add Single Driver.  Purple indicator appears.
Create a new window or reuse window. Change to Graph Window.  Select [Drivers] editing context.  Make driver info appear by click the + sign faintly visible on the right side of window if necessary.  Add variables and create your variables to match the values in the screen captures above.  Note the object names I use may not be the same as your object names.  Thus use the object names in this proposed answer or translate with awareness.
The red cube need not be rendered.
Make sure  User Preferences allows scripts to be executed  ... if a related error message appears.

hmm this is a bit confusing, the interface looks different to me. Can you explain it in step by step, a more noob friendly example please :)

Now you must take time to understand the above. Its not trivial but it is worthwhile. Take a few minutes to reflect.  Be adventurous.  Once you have practiced ... all the driver window activity will be 20 minutes or less.  Eventually 8 minutes with practice. Every Blender use can change the colors and and window layouts.

sorry but this didn't help me. thanks for your time. im sure it will help someone else who wants to read it

Copy Location Constraint

For certain cases a
[Copy Location] constraint
may work.  In the settings above note that the X axis is used, offset used, and one object has invert specified since the objects move in opposite directions.  For the current settings we rely on the red DeltaObject being a Location X = 0 for rest position.
Note the image above contains two screen captures.  You can read which object is selected on the left and differently on the right sides.  The highlight is often difficult to see.

Click to see larger image.

authors: เบียร์ เลิศศักดิ์


text:
Blender is exporting the wrong UV coordinates
I was making an axe model in blender but when i loaded it into my game engine the texture wasnt right. I tried making a textured cube to find the problem. When editing the texture in blender the cube renders properly, but when I export it the uv coordinates become seemingly randomly jumbled. I have checked the uv coordinates manually by going into the file and checking them and something is definitely not right.
I'm including the texture and the obj file contents below:

Link to the obj file

What happens when you try to re-import the model and apply the texture to the imported model? Is it still screwed up?

@Kirbinator I imported the .obj file into blender and then applied the texture to it. It worked fine. It looked like it should. I tried the exact files again in my game engine but still no change.

It comes out fine for me as well.  I have to assume it is something your game-engine is doing.

I have tested my engine many times while developing it and I have checked the obj file parser code twice. Like i said in the main part of the post, I went into the file and manually checked the uvs against the vertices on a piece of paper and the uvs are not exported properly

Maybe It's just your game engine that imports it wrong?

It wasnt. You're right. The obj file parser I was using couldn't handle texture seams. That's why it didnt work

I've just realised that I didn't post my solution to this problem. The problem was with my game engine code. My obj file parser couldn't handle texture seams and so it made the whole thing look dodgy.

Two things to check:

Make super sure that you are indeed exporting the UV's when you export the obj.

Make sure that your game engine is consuming the UV information properly.

If I didn't export my uvs my engine would crash and give me an error. It requires uvs to be present,and they are. The engine also does take the UV information properly. I have tested it with other people's models and it works fine. Like i said, the UV information exported doesn't correctly map against the texture

When I export I use the settings:apply modifiers, write normals, include uvs, triangulate faces and objects as obj objects


text:
Quickly find the selected vertices on my model
In the Edit Mode, on the header, click:
Select -> Select All by Trait -> Faces by Sides
Then the new menu on the lower left of the screen says 4 vertices have been selected.
The problem is that I can not find those 4 vertices on my mesh. The 4 vertices must be in orange color, but I just can not find any orange color on my model, which has 2 million vertices in total.

So how do I quickly find the locations of those 4 vertices on my model please?

Numpad period quickly zooms in on selected vertices (or selected anything), which should do the trick if the four verts are all close to each other.

Thanks for the comment! I have pressed the number 3 on the numpad, but it does not zoom in much, so it may implies that the 4 vertices are not close to each other.

Btw the menu doesn't show vertices selected, it shows which faces to select - in this case: quads ;)

@JachymMichal   So 4 means the vertices of a quad, not the vertices on my model. I think you are right. If you write your solution, then I mark it as the answer. I have a poor understanding on how to use "Select Faces by Sides".

No problem, answer is up including a gif (i'm a sucker for those ;)

@BlenderLake By the way, Numpad 3 is not supposed to zoom in (it might just happen compared to whatever you were viewing before), it's for changing the view to the right side, in the menu View > Viewpoint > Right.

@Nathan  and Gordon Brinkmann,  I am sorry about my mis-typing. I am using a laptop which does not have a numpad, so I have to press "~" and then "3" to view selected vertices, instead of the period key....  And I have tested whether using "View Selected" can actually find the selected vertices. You can find more details from my answer below.

The menu doesn't show vertices selected.
It shows which faces to select - faces made by four vertices.
There are no such faces in your mesh, so no vertices are selected.
(hence the infobar in lower right showing (0/704 248)

To completely answer my own question, I have explored another example:
Select -> Select All by Trait -> Non Manifold
Then 26 vertices out of 800,000 are selected. Now, let's use "View Selected" and zoom in to find those selected vertices. But can I find them?

By the way, I am using a laptop which does not have a numpad, so I have to press "~" and then "3" to view selected vertices, instead of the period key. And I have to use Ctrl and "+" to zoom in, instead of just "+".
From the video recorded above, I could not find any selected vertices, even using "View Selected" and zoom in.
My solution:
After selecting "Non Manifold", on the header, click:
Select -> Select More/Less -> More

Then repeat this action for several times until I see the orange selected color appeared on the head:

Now I know where those 26 vertices come from.


text:
impossible to render a video
I use blender as a video editor.
I did create/ cup my movie but when I want to render it, I see the render window, the frame counter that increment but no image.
When finished, I check the result and I have a fully black movie that last the timing of my editing.
I did set the parameters to beginning frame and end frame, did choose FFmpeg video with encoder set on MPEG4 and H.264.
I did refresh my codec in my computer : no change....
I'm lost and don't know what to do.
I did open an 3D model I did and try to render an image of it = same result. No image.

I don't know how to check and or change the video codec output settings.
In blender, my settings are

...and my rendering engine is set to "Eevee"

This can often be caused, in my experience at least, by using incorrect/incompatible settings in your video codec output. I'd suggest reviewing those and/or sticking to presets if that helps, but I can't say much without seeing what settings you're using. May help to edit your post with some screenshots.


text:
How to Extrude Circle Inwards Evenly?
I have this circle that I am trying to extrude evenly, but it doesn't extrude properly.
I pressed E, then ⎇ Alt + S, then when I drag in it go slightly at a downward angle.

I am following a tutorial and for some reason my ⎇ Alt + S doesn't extrude evenly.

Put the 3D cursor at the center of the circle (in Object mode you can press ShiftS > Cursor to Selected if the origin of your circle is still at its middle, or in Edit mode select the 2 extremities of your arc and then ShiftS > Cursor to Selected), choose the 3D cursor as Transform Pivot Point, and scale the extrusion:

should i always have it set to 3D cursor for everything I make or just for this example?

just for this example, most of the time leave it to the default setting which is Median Point

ALT + S is used to scale geometry along the normal, if it behaves like this when you press ALT + S it's because your normals are facing that way.
I don't know what is the tutorial and I don't know what you did differently compared to it but normally if you have a circle, the normals of each vertex should be pointing to the center of the circle so even when you delete half of the circle, you should still probably have this when you extrude and do ALT + S :

So the best solution for you would be to start over, create a new circle and delete half of it but if, for some reason, you can't redo everything from the beginning, you can do the following :
Select the two vertices at both end of your half circle

Press SHIFT + S choose Cursor to Selected :

it will snap your cursor at the center of your circle. Then, change the pivot point to 3D cursor :

Then, press E then S to scale the vertices and it will scale them according to the 3D cursor :


text:
3.3 Keymap for 2.79
I have been doing some retro looking renders in 2.79 as of late, but I am unfamiliar with its Keymap and switching between 3.3 and 2.79 breaks my workflow quite a bit. Is there any way to quickly update 2.79's keymap?

Highly unlikely I would imagine. If you could say and post an image of what sort of "retro looking renders" you want I'm sure someone will be able to suggest how you can create them in blender 3.3.

I will do so! Thank you for the suggestion. I will keep this question unanswered in the event that someone solves the initial issue.


text:
Object messes up in animation
I`m new in blender, anyone can tell me what I have done wrong, my object messes up while animating, take a look at the eyes from the image.. and edges became very strange, armatures of the arms are out of places.

this happens when you dont add keyframes to all your objects and they move to whatever you animated them to do , from the 1st frame , probably this is the same problem , have a look at the separate poses of the objects

I have added keyframes but still the same. Thanks a lot for your time.


text:
Why my light doesn't appear when I activate Cycles render?
I add some objects and lights (I use area). Then I enabled display render preview using Eevee, and it work. But when I switch to Cycles render, the lights don't appear, I just saw my plane and some objects. Can someone help me solve this?

hello could you please share your file? https://pasteall.org/blend/

sure, here is https://pasteall.org/blend/f147ca678d0f47f7ae6ed5e1dcee3846

It's not because of your lights, it's because of your plane material, its Material Output is set to Eevee instead of All:

OHH, got it, thank you very much, sir.


text:
When transforming or moving object, all or many other objects are affected
How do I separate objects in blender 3.0 so that when I move or transform one object others are not affected?  Why is this happening?

Sounds as if you have Proportional editing enabled (white dot icon on the top toolbar). Press 'O' and see if it stops.

they could be parented to each other. try selecting everything and pressing Alt + P and selecting "Clear Parent". could you provide the .blend file?

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


text:
Ctrl-Z deletes texture when texture painting
Does anyone have a solution to this? Sometimes when I Ctrl-Z when texture painting and I haven't saved my textures to a PNG yet, it deletes the whole thing. Which makes me have to start over again. It's happened a lot the last few days, I hope someone can help me out.

Ctrl Z doesn't always work as we expect, maybe report it to Blender developers so that it changes?

yeah this is also a thing when im weight paining with a mask. it removes the weight and the mask instead of just the weight. hopefully blender fixes this

https://blender.stackexchange.com/q/1377/110840


text:
Exporting with .fbx does weird stuff for me
I've been racking my brain and searching the internet, but maybe someone here can help me out!
I have this object that has an image texture on it. And when I export it to FBX (with copy and embed textures) it exports like this:

This is the object before I export it:

I'd love to hear what I'm doing wrong or if there is something I haven't thought about.
Cheers,
Lo


text:
Meshes have missing/transparent faces after applying an explode modifier?
I'm trying to apply an explode to an object. I have set the start point for the particles at frame 25 but this leaves my mesh in a fractured state prior to the explode with seeming missing or transparent faces in places.
I have checked the normals and searched the internet looking for a clue... any help?
Latest blender 2.8 windows 10 install.

Welcome to Blender Stack Exchange! Does your animation also start on frame 25? If so, that will cause issue. If not, could you upload your blend file so we can take a quick look? You can upload it here: https://blend-exchange.giantcowfilms.com/ Otherwise screenshots of particle/modifier settings would be helpful too.

Hi mate. wont let me upload as the file is over 30mb's

https://blend-exchange.giantcowfilms.com/embedImage.png?bid=6776

sorry i just quickly remade the file without materials.. if i remove the remesh modyfier the entire front face is missing?

Hi sorry lol.. I just sent another file.. Simple standard cube.. subdivided to 50.. applied explode and now 2 faces are missing/transparent?

The link is only to the download button image, not the actual download link. At the bottom left of your question there is a small edit button. Click that to edit your post. When you upload your blend it will show you some text to include in your question. Copy paste that text into your question and save the edits. Then I will be able to download it.

Its ok! I managed to find a work around to stop the affect happening. I had to delete all automatically generated materials and textures from the quick explode function and then setup new ones.. this immediately solved the issue. thanks guys! x


text:
How to add perpendicular spout to cylindrical water faucet main body
I'm really new to 3D-modeling so I apologize if this is a really simple concept, and I also apologize if this is the wrong place to ask a question like this.
I'm trying to model this water faucet:
And I currently have:
I'm stuck on how to proceed with the perpendicular spout section. Is there a way to do it without creating another object and then using bool union?

Using Boolean would be probably worst idea. Could you please upload blend file to: http://blend-exchange.giantcowfilms.com/ ?

@LukeD I added it to the main post.

Basically you only need to extrude part of the mesh, then remove some faces and rebuild desired shape. I cannot give you answer today, but if nobody else make it, I'll make one tomorrow.


text:
How can i make Ken Burns effect with animation nodes?
I have a camera and an image in the scene.
I would like to achieve random Ken Burns effect on the image with animation node with the constraint that the image will always stay inside the frame never showing the background.
I have achieved a simple Ken Burns effect where the image is zoomed and translated in only one direction. I would like to set a duration and then the animation node would navigate the image.
For example the duration would be 15s:  [0,3] the image scale and translate in one direction, [3,10] the image scale and translate in another direction and so on.
Thanks.


text:
Object scaling preventing retargeting of rigify rig to bvh with MakeWalk
I created my rig from rigify armature and it is working beautifully.
The issue now is I want to load some mocap bvh files on it, I'm using MakeWalk addon but when I try to load the bvh file by clicking in "Load and Retarget" button under the Misc Tab I got this error:

I searched a lot I didn't find any clue to solve this... using a regular rig or makehuman rig would be a pain in the a*% for me since Rigify is amazing and I am pretty used to it.
any tips are welcome thanks

It is telling you that your rig scale in object mode is not (1,1,1). Select the rig in object mode and hit ctrl-A  and select scale from the menu to apply scale.

you are correct

Apply Scale
The warning indicates the rig scale in object mode is not (1, 1, 1) (unity). Select the rig in object mode and press ctrl-A-S, or select via the Object > Apply > Scale  menu, to apply scale.
It's the same process as selecting all bones in edit mode and scaling to match the current size, with unity object scaling.


text:
Is it possible to add modifiers dynamically with animation nodes?
To add modifiers dynamically, I know that one can modify values of existing modifier via attribute output node. Can this node be used to create modifiers or does it need some sort of scripting?

try pressing I over the Eye Icon of the Modifier

sorry I dont know Animation Nodes but that would be the way I would try to do it

No that´s not the case. Needs to be added dinamically

but it would be not effectively there if you hide it. That was my thought

The only way to do this is by using scripting, there are three important points to take into consideration when making this:

Make sure not to add the modifier if it was already added in a previous execution.
Output the input object and plug it into the attribute output node, making sure you are not editing a modifier before it gets added.
The modifier name should never be an empty text because then blender will automatically add a name and our first test will fail, so we should set a fallback value.

Making sure we got those three points right, we can write a code like this:
modifierName = modifierName if modifierName != "" else "Fallback"
if not modifierName in object.modifiers:
    object.modifiers.new(modifierName, 'ARRAY')
outObject = object

Great!!! This was what I was looking for.


text:
How to rotate a bone around multiple times? It just snaps to closest rotation?
I have some fans that I need to rotate using an armature:

the problem here is blender's bone posing system makes it so if you key a rotation, then rotate around multiple times, blender just goes to the closest rotation. I cant have this - I need to keep spinning (like a fan).
how can I do this?

In the 3D View properties panel (activated with N), or in the Properties panel > Bone > Transform, switch the rotation mode from Quaternion to XYZ Euler, otherwise you will have the kind of problem you describe.
If you want your rotation to be linear (and not accelerate and decelerate, which will happen by default), go in the Graph Editor, select all and click T > Linear.
If you want the rotation to be infinite, select all and press shiftE > Linear Extrapolation.

A cycle and the NLA
Simplest way would be to change to Euler rotation and use the method in @moonboot's answer
To remain with quaternions  Another option is to make a cycle and use the (oft forgotten) NLA to scale and repeat the action.
Here I've made an action to rotate using quaternions, about Y axis one revolution in 24 frames. Rotated in two parts from 0 to 180 and from 180 to 360 (0). Converted to linear interpolation.
At 24 fps is 1 rev per second or 60 rpm.  Switched the frame range to 1 to 23 to test.

One rev in Y in quaternion. Have removed the non required X and Z and the middle keyframe of W
When happy with cycle, "push down" the action to the NLA.

Switch to NLA editor. In Action Clip panel set the end frame to 23 (one less so next frame is back to 0 or 360 degrees)

Use repeat for revolutions and scale for speed, reversed for switching direction. These properties can be animated.

Hit "N" and set the rotation manualy under the tranform tab.


text:
Bug separating an array of cubes in blender 2.90?
I'm new to blender, but looked at several videos and tutorials and tried to do it in 2.90.0.
Starting from a simple cube, created an array in 3D (3 arrays in X, Y and Z), fixed distance, leaving some space between them.
Entered Edit mode (array selected), here something was already strange, tried to see everything selected, was not possible until I´ve activated the Object Data Properties selector in the array modifier.
Then hit P and selected By Loose Parts, but nothing happens. Just keeps where it is.
When the Object Data Properties selector in the array modifier is NOT selected, then all the array does not select in Edit Mode.
After trying again and again, starting over, new file, etc. I´ve download version 2.83 LTS and made the same thing, and it worked. Tried 2.90.1 and this version also did not work.
Did something change in a way which is not documented and I´m missing something?

I might be misunderstanding the events here but would this be an answer?   The array modifier doesn't actually add meshed copies of the object, meaning they can't be separated in Edit mode 'cos there's no extra objects to separate.
The modifier would have to be "Applied" first.  Go into the Modifier list and click on it's 'Apply' button.  This will convert the 'ghost'  copies to hard  mesh, but all as one object.  They can then be separated in Edit mode when all vertices are selected and 'P' is pressed.

Script version re comment above https://blender.stackexchange.com/a/61254/15543

Thank you for your reply, but in version 2.90, there is no more an Apply button, as there is in version 2.83. That´s a difference. That is why my question was also related to if there was any workflow change that was not documented and distinct to the way it´s done in 2.8X. In 2.8X I have used the Apply buttom.

I too downloaded the new version and there is no more apply button. Instead, there is a drop down next to the camera icon and you can select apply or press Ctrl +  A it seems.
I was able to separate pets in edit mode then.


text:
normal pass from volumetric shader [EEVEE]
I'm trying to export a kind of Normal Pass from a group of cubes with a volumetric shader inside.
Is it possible to do? I'vesearched a bit and I've found some tips for recreating normals into shaders, but when I try to transport it into volumetric all goes wrong.
The file if you need it:

Volumetric (only) mats do not not have normals, because normals are a property of surfaces.  The best that you're going to get from that is getting the normals of the cubes defining the volume.  You are not going to get the apparent surface of some cool procedural volumetric, because that surface is only apparent, not actual.

Oh, ok, but is there a way to simulate that? I mean a way to make rgb colors to appear in three different direction? (Like normal pass do?)


text:
Missing Settings on Light Point Menu
I am new to blender, trying to edit light and shadow parameters. I came across the following.
I had added a light point to the workspace. When I click on it (the light point object), the menu on the right-hand sidebar does not display the Light settings that I would expect.
The available settings are Transform, relations, collections, instancing, motion paths, visibility, viewport display, and custom properties.
I have looked for any light or shadow properties settings but I cannot find them.

Hi and welcome :) What are the settings your expecting to see? Would you mind editing your question and adding an image or two to clarify please what you are trying to do? This will help others help you. Thanks :)

I found them, they were just on a separate tab (withing the right-hand bar menu) instead. Which holds these properties.


text:
Making little holes in mesh
I'm quite the beginner with blender (just finished the donut) and I wanted to make a 3D replica of a radio that I have, but I have no idea how to make the little holes properly that it has in it.I assume the best way to make it is with the boolean modifier but it takes my pc like 30 seconds to calculate. Is there a better way to do this?

These are my modifier settings:

link i used these settings

@batFINGER already tried boolean and that didnt work properly, maybe the first solution in that post could work but I already got an answer to my problem thanks to moonboots

I'd use a honeycomb object for that. In Preferences > Add-ons, search for 'extra' and check the Add Mesh: Extra objects entry.

https://blender.stackexchange.com/questions/65395 https://blender.stackexchange.com/questions/58811 https://blender.stackexchange.com/questions/51233

You could fake holes with normal or bump maps, but if you want to create real holes, create a plane, subdivide, select all except the borders:

Press CtrlB to bevel the vertices (go into the Operator box to select Vertices):

If you want more than 4 vertex holes, increase the amount of Segments and choose Shape > 1 to make them round:

In Face Selection mode, select one face and press ShiftG > Polygon Sides to select all the similar faces:

If you ever change the holes size, choose Transform Pivot Point > Individual Origins. When you're good, press i twice to inset each face:

Extrude down a little bit, then again twice, then give it a Subdivision Surface and Shade Smooth:


text:
How to mix and animate a lot of shaders
So I have 12 shaders of rather complex materials. I need to be able to smoothly mix between these shaders and be able to animate this mix.
At the moment I have this setup (12 shaders into a mix shader tree):
I can animate the factors of this Mix Shader tree to get the smooth changes I need but this is a lot of work to change between materials as I have to keyframe a lot of factors. Is there a way to have a Switch Shader node? Or to create one?
Thanks

What about using drivers?

Hi :). Do you only want to switch between shaders, or blend between them gradually?

You can add a value node which takes numbers 1-12 and calculate from these the settings of your mix nodes?

Hi, I want to smoothly "switch" between them. So yeah blend :). I do not know what drivers are, I will check this.

The calculate way is not super flexible I think? As it does not let me choose what materials I want to blend?

I am now trying this which is already a lot more usable: https://imgur.com/JqMpRX9 and https://imgur.com/fogVAW1


text:
Bone's Location transformation coordinates disabled
I was working with Rigify Rig for a character and created some of the bones, however, while working in pose mode, it appears that the location coordinates of all of the newly created bones are disabled but rotation coordinates are enabled. I would like to enable the location coordinates.
For reference, a screenshot is attached.

Loc is disabled because theese bones are connected child of the previous bone on the chain, so their location is determined by that parent bone.
If you want to control the location also (and so disconnect the bone from the chain), you have to go to edit mode, select the bone and press Alt P > Disconnect Bone.
The bone will remain child, but unconnected (keep offset only), and you'll be free to move its location in pose mode.
Be aware that if the chain has some mechanism, like IK, it could get broken.


text:
RAM size for Rendering in Eevee
Currently I am using 16 GB RAM in my system. If I increase RAM by another 16 GB, whether this will help me to reduce Render time in Eevee (Blender edition 2.9.3.4), if other system specifications remains same?

I imagine this might depend on what you are trying to render.

Render time was base on CPU and GPU. Bigger RAM means bigger data that machine can handle, for RAM on GPU it mean bigger texture and polygon. You can check  benchmark data at https://opendata.blender.org/

When your scene fits in your RAM, the amount of RAM doesn't change the render time. It will only change how much data you can load, how much you can chew before it has to use your disk, which is then drastically slower.
What can have an impact on render times with RAM is its clock speed. Faster RAM makes you load and unload that data faster. Especially if you also upgrade from DDR3 to DDR4.
But most likely you are not concerned by this change if you only want to add more RAM stick to what you have: your motherboard can't support both memory type as they have different specs and plugs. And if you use different clock speeds, your motherboard would probably just automatically underclock the faster one and you won't profit of the faster speed.
So basically, the only way to profit of a faster RAM is to change the entire RAM kit, and maybe even your motherboard if the one you have right now doesn't support DDR4 and/or faster clock speed.
THAT BEING SAID:
Unless you need to render heavy scenes, RAM is not the biggest factor in render speed. CPU and GPU are the number one factors. If you want to do GPU rendering primarily, focus on that. But don't ditch the CPU neither, having a somewhat balanced configuration is important : your config is as strong as its weakest link. Even when doing GPU rendering, Blender still uses CPU for some tasks like BVH baking and whatnot.
TL;DR:
If you need speed, you probably want to upgrade your GPU and CPU first.
If you are not comfortable to choose hardware for your needs, don't hesitate to get help on some hardware config forum. There are a lot of people happy to help out and get the best you can afford for your needs.

The amount of available ram affects the working set size, which in turn affects paging.  If the WS size becomes too large, the program will swap pages and performance will degrade dramatically.

Damn I forgot about that, good catch!

Though I wonder how this works particularly in Eevee? AFAIK Eevee is an OpenGl render done by the GPU, yet the RAM is also used, but what is being charged to either VRAM or RAM?

The rendering itself is only ever going to use the video ram, so it's either you have enough video ram or you don't.  But the modifiers are going to use system ram, and could potentially fall back to swap drive.


text:
Mesh modification by Proportional editing in Shape keys
I am using Blender 2.9.3.4. During character creation process, after rigging, whenever I add shape keys and then modify the mesh with Proportional editing, in edit mode. It is found that proportional editing always give influences in a mesh which is far away from the desired area.
I don't know whether this is glitch in Blender?

In the Proportional Editing panel, have you enabled the Connected Only option?

Also, what size is the circle of influence?

Connected only option enabled and the size of circle of influence is also very small. One thing I want to add here, that this issue is not happening prior to rigging the base mesh. After I rigged the character, influence of other meshes in proportional editing is appearing.

I was facing the same problem. It is not a glitch, the problem is that Blender uses the rest pose to compute neighbor vertex influence, this is why editing vertex on a posed mesh can be so awkward (proportional editing, smoothing, etc.)
The solution I found is the following one:

Pose the character the way you need.
Create a new shape key.
Click the "V button" in the shape keys panel and select "Create
duplicate for editing". This will create a new linked mesh, without
armature and without shape keys, but with the shape of the posed
mesh.
Edit the new mesh to achieve the shape you need. Now you don't have
the editing issues mentioned before. You don't need to create any
shape keys in this new mesh.
Once finished, go to Object Mode. Select the "clean mesh" and then
shift-select the original mesh.
Go to the shape keys panel and select the shape key you are working
on. Click the "V button" and select "Add as corrective pose-shape
(slow, all modifiers)".
Finished! You have a shape key that works correctly on the posed
mesh.


text:
Keyframes transfer from FK to IK bones
I am having a character  animation with simple hand movements.
The character is rigged with rigify and in hand movement animation, the keyframes are inserted on FK hands. Here, I would like to transfer the keyframes made of FK hands to the IK hands. Please help.

care to share your blend file https://blend-exchange.com or share some screenshots?

I am attaching the Google drive link of the blend file. You can find that all keyframes are inserted on FK hands & legs. I want those keyframes to be inserted on IK bones. Link: https://drive.google.com/file/d/1oN0iUiikkkqh0i0u5gJm8UO9OV2qQrzI/view?usp=sharing


text:
Issues in Viewport Shading
I am having a city model. However, the issue is when the file is opened in Solid mode, the model is working fine but when the model is opened in Material preview mode or Rendered view mode the model is showing some display issues.
Both the screenshots of Solid view mode & Material preview mode are attached.

Try going into the material properties for one of the materials (the "tree leaves" for example) and see what the Blend Mode is set to. If it set to alpha-blend, try enabling/disabling backface culling and/or show backface (alpha-hashed and alpha-clip will only have the backface culling option).

to add to Christopher's comment, try the Opaque setting instead of Alpha Blend

Thanks Christopher Bennett and moonboots. Your suggestions worked and my problem is solved now.