text:
Is it possible to have automatic LOD (level of detail) on large scenes?
Objective: build a virtual suburb in blender for use in creating exterior shots (not realtime: shots will be rendered in Cycles).
The angles of these shots will not be known in advance, so it's impossible to guess in advance which elements need to be high detail and which can be low detail.
Large scene becomes unwieldy and incredibly memory-intensive with hundreds or even thousands of high-detail objects, especially when many are not in shot. Scene will be utilized by an artist on home computer, so excessive memory use is not viable. Convenience is the primary objective to maximize efficiency in setting up and rendering shots. Renderer to be used is Cycles.
The higher detail of the nearby models would not necessarily be provided by subdivision. A perfect example of the sorts of things I'd be working with are buildings; up close, they would have fully modeled doors, windows, and other small details like flags, while far away, those fine details could be baked into textures, made more rudimentary, or simply omitted altogether.
Is it possible to automatically swap out lower detail meshes/materials at long distance for these renders?
I am also interested in alternate solutions. Since there are only 20 layers available, the only alternate solution I can come up with would be to divide the suburb into sections and have a high-detail and low-detail version of each section put onto adjacent layers, which the artist will toggle based on the position of the camera and what is visible in the shot, but this would be less than optimal. Any other ideas are welcome.

Maybe this addon is for you: https://cgcookiemarkets.com/all-products/lod-manager/

This appears to be a perfect solution to the problem at hand, thank you! I wish you'd offered it as an answer, I'd have marked it as the correct solution to the problem~

A link isn't considered to really be an answer here at BSE, that's something we usually put in comments. Furthermore, the plugin is commercial, even though the price is really more than fair. I was thinking about putting together a small script to switch models based on distance to camera, when I had the idea to browse what's on Blender Market already. And bang, exactly that in a more professional shape was available already  :)

Well, I suppose that is understandable enough, though the question was "is it possible;" commercial product notwithstanding, it does demonstrate the viability of the premise and simultaneously provides me with the specific solution I need. So thanks again!

Why does the link always redirect me to https://blendermarket.com/?

@piegames the link has changed, as the blendermarket website received an update: https://blendermarket.com/products/level-of-detail-manager

i make "Auto LOD" addon, its make an lod for your objects base of the distance from the main object, i think its can help you
https://blendermarket.com/products/blender-auto-lod

I have two pretty detailed posts that when added together, would seem to come up with a pretty good fit for your situation.
I won't detail out those steps, but I will link to them, and summarize the workflow in a summary of logic.
Creating Distance/Rotation/Scale Based Drivers - See this post
Swapping Groups of meshes with drivers - See this post
The main rundown here, would be to drive your level of detail threshold by camera distance values, then using the same logic of swapping groups of meshes, use this threshold value to determine which LOD group to select on any given instance with this driver attached.

I'll have a looksie and see if I can get it working :9

Sorry for the long delay, but this has worked perfectly. Marked as the answer, thanks so much :9

If you enable Experimental will you get 'adaptive' in the Subsurf modifier:

Just enable adaptive and you shouldn't need to do more.

If it uses too much RAM you should use these settings:

The subdivision rate is how many pixels it is between each subdivision. If you increase the value it will decrease the quality.
For more info try this Youtube clip
https://youtu.be/dRzzaRvVDng

I think it would be helpful if you explained what the 'Adaptive' option is meant to do and how it will help. Same goes for the 'Geometry' settings.

I will be away untill monday. The last edit shuld be enoth to understand Ad/Ge if I diden't go to lasy on the english. @ray_mairlot feal free to clean the answer if you like, the other you have done have been aprichiated

Sorry that I missed this answer when it was posted, I've been away from the Blender scene for a while.
I don't believe this suffices for my situation; the detail in the meshes is not something that subdivision provides. I will add more detail to the question to better explain what I'm looking to accomplish.


text:
How to get this type of light streak in blender render (In Animated Format not Rendered)

I've looked through the blender tutorials on YouTube and others, but I cannot find the correct one for this effect. How can I make that kind of light streak as in the picture (behind Sonic The Hedgehog)

You want it for a still render or you want to animate it?

In Animated format please.

would this answer be useful? https://blender.stackexchange.com/a/94976

source: Stack Exchange

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

sort: votes


text:
How do I fix the "context invalid" issue when using python method weight_paint()
I have the following test code that I am getting the infamous:
"RuntimeError: Operator bpy.ops.paint.weight_paint.poll() failed, context is incorrect".

I cannot figure out what the context issue is related to, is it the values for the stroke that I am trying to use, or selection, or something else.  Any help would be greatly appreciated!
Setup: a single plane that is subdivided multiple times it contains a single vertex group with all vertexes included called 'test'
Code:
strokes = []
brushOp = {
  "is_start":True,
  "location":(0.0, 0.0, 0.0),
  "size": 1.0,
  "time":0.0,
  "pressure": 0.0,
  "pen_flip":False,
  "mouse":(0.0, 0.0)
}
strokes.append(brushOp)
strokes.append({
   "is_start":False,
   "location":(1.0, 1.0, 0.0),
   "size": 1.0,
   "time":0.0,
   "pressure": 0.0,
   "pen_flip":False,
   "mouse":(0.0, 0.0)
})

bpy.ops.paint.weight_paint_toggle()
bpy.ops.object.vertex_group_set_active(group='test')
bpy.data.brushes['Draw'].stroke_method = 'LINE'
bpy.ops.paint.weight_paint(stroke=strokes, mode='NORMAL')

are you running this from a text editor or in the context of an addon?

Related http://blender.stackexchange.com/questions/6101/poll-failed-context-incorrect-example-bpy-ops-view3d-background-image-add/6105#6105  Make up a context override dictionary (prob: "window",  "space_data", "area", "region") and pass it to the operators.

@aliasguru: I am running it from the text editor.  What I would ultimately like is to run it from the command line with no UI at all.  Maybe this just isn't possible for all ops.paint methods.

I believe it is possible, the link batFINGER posted before contains methods to create a 'fake' context and pass it to the operators. So in essence, you pretend that the function was run from 3D View, even though it was run from the console.

@aliasguru: Yes, that was a great link and good information regarding how to override the context (certainly a piece that I was missing).  Unfortunately, when I override the context with what I think makes sense, it crashes blender.  Grateful to you both for the insight you have given me.

Added an answer with aforementioned context override, doesn't crash my blender.

When making your stroke list via python you will need to add a name key to your StrokeElement dictionary.
Also override context for area, space_data and region.
import bpy

strokes = []
brushOp = {
  "name": "Bob",
  "is_start":True,
  "location":(0.0, 0.0, 0.0),
  "size": 1.0,
  "time":0.0,
  "pressure": 0.0,
  "pen_flip":False,
  "mouse":(0.0, 0.0)
}
strokes.append(brushOp)
strokes.append({
   "name": "Bob",
   "is_start":False,
   "location":(1.0, 1.0, 0.0),
   "size": 1.0,
   "time":0.0,
   "pressure": 0.0,
   "pen_flip":False,
   "mouse":(0.0, 0.0)
})
print("-" * 72)
context = bpy.context
screen = context.screen
c = context.copy()
for a in screen.areas:
    if a.type == 'VIEW_3D':
        c["area"] = a
        c["space_data"] = a.spaces.active
        c["region"] = a.regions[-1]

if context.object.mode != 'WEIGHT_PAINT':
    bpy.ops.object.mode_set(mode='WEIGHT_PAINT')
bpy.ops.object.vertex_group_set_active(group='Group')
bpy.data.brushes['Draw'].stroke_method = 'LINE'
bpy.ops.paint.weight_paint(c, stroke=strokes, mode='NORMAL')

having exactly 6.000 rep points looks very cool, but I just have to upvote this answer, sorry  :)

This most likely needs to be wrapped in an add-on that is in the 3d view (as in the button to call this is in the 3d view so that the last user input before this runs is in the 3d view). An operator class, like when you call bpy.ops.paint.weight_paint(stroke=strokes, mode='NORMAL'), often has a poll function as this one does. A poll function basically checks for certain criteria to be met before running its execute method, and one of the most common checks is if the context is correct. If you are running this from anywhere other than the 3d view in weight-paint mode, the context will likely be incorrect.
Here is an add-on demo (very heavily commented):
# Blank Addon

bl_info = {
    "name": "Blank Addon",
    "author": "Anonymous",
    "version": (1, 0),
    "blender": (2, 76, 0),
    "location": "3D View > Tools > Blank",
    "description": "A completely blank addon ;)",
    "wiki_url": "",
    "category": "3D View",
    }

import bpy
from bpy.types import Scene, Panel, Operator
from bpy.props import IntProperty

# UI...this creates a new panel in the 3D View
class BlankAddonPanel_PT(Panel):
    # name of the panel...
    bl_label = "Blank Addon"
    # used to register panel
    bl_idname = "3D_VIEW_PT_layout_BlankAddon"
    # specifies to make panel in 3D View
    bl_space_type = 'VIEW_3D'
    # it is in the tools not the properties region
    bl_region_type = 'TOOLS'
    # only show panel when in object mode
    bl_context = "objectmode"
    # name of the tab for the panel
    # (if this is 'Tools' it will be on the first tab)
    bl_category = 'Blank'

    # the meat of how to draw the panel
    def draw(self, context):
        scene = context.scene
        layout = self.layout

        # create a new column and label it column
        col = layout.column()
        col.label("Blank Column", icon="COLLAPSEMENU")

        # create a button that is linked to the operator
        col.operator("scene.blank_print_ba", icon="QUESTION")

        # create a property field linked to the prop
        col.prop(scene, "blank_prop", slider=True)

# Operator this is setting up what the "button" executes
class BlankPrint_PT(Operator):
    # the label for the button in the UI (if not overwritten in the panel code)
    bl_label = "Do Nothing"
    # the name of the operator (only used in python ie. for ui)
    bl_idname = "scene.blank_print_ba"
    # tooltip for when user hovers over button in UI
    bl_description = "Prints useless information =)"
    # options: can be registered, support undo (Blender does this for you)
    bl_options = {'REGISTER', 'UNDO'}

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

        # this is where the meat of your operator would go :-]

        # send a message to the info bar
        self.report({'INFO'}, "I didn't do anything :-D, but your prop is " + str(scene.blank_prop))

        return {'FINISHED'}

# classes to register/unregister
classes = [BlankAddonPanel_PT, BlankPrint_PT]

def register():
    # register each class
    for i in classes:
        bpy.utils.register_class(i)

    # create props
    Scene.blank_prop = IntProperty(name="Blank Prop",default=1,min=0,max=100)

def unregister():
    # unregister classes
    for i in classes:
        bpy.utils.unregister_class(i)

    # delete props...it's very important to delete each prop
    # you add in register here!
    del Scene.blank_prop

if __name__ == "__main__":
    register()

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


text:
How come when I use "GPU Compute" in Cycles when rendering the entire render changes?
I've recently been looking everywhere as to why this is presenting as it is and I have found 0 solutions. I have a simple grass setup that displays just fine in EEVEE and "Cycles-CPU". As soon as I try to use the "GPU Compute" option, the entire scene goes dark, with odd reflections. Attached below is a before and after, CPU and then GPU Compute.

I apoligize as I did not include my specs. I'm running on a laptop with the Intel-i7 and the RTX 3070.  Also a noticable error with the GPU Compute are these black boxes that are all over the render. Some spaces are a bit brighter, and others you can see just black box outlines.

Hello and welcome. Could it be overlapping vertices? If not please share a minimally reproducible file https://blend-exchange.com

Sorry for wasting your time. It was the texture that was at fault. I tried out a couple more and some of them have this same issue and others work just fine. Pulled from BlenderKit. I am new here so what should be done about this page now?

No worries. You can leave it or even delete it if you want.

@XanderWay Just as tip for the next time: since we cannot always know what exactly is going on and as you discovered it could as well be the textures, it's not a bad idea to share a screenshot of the material nodetree as well, sometimes this can help discover problems because there are some nodes which are only working in Cycles, some just work in EEVEE and other times it might just be an error in how it is set up  in general.

Roughness values < 0 or > 1 can cause this kind of artifacts

Alright, thank you all for your help. It is much appreciated.

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


text:
Portable Blender isn't saving text extrusions
I'm using Blender 4.2.3 LTS via a Portable Apps installation on Windows 11 pro. I have a bunch of text objects that are snapped to faces (making a D20). I am extruding the text in the Data > Geometry > Extrude. After I've saved the file, closed out of blender and reopened, the text is no longer extruded. The extrude value of each is set back to zero.
I don't want to convert the text objects to meshes so the I can easily change values/fonts later.
I added a text object with the same settings that's NOT snapped to the surface and it reloads as expected. I'm not sure if I'm missing a setting that would make it behave correctly. Is this expected from the snap feature?

What's "Blender 4.2.3 LTS via a Portable Apps installation on Windows 11 pro"? What does that mean? Portable Blender is the one you download in a zip archive, extract anywhere and run without installing.

That would be a version packed by https://portableapps.com I don't think it has anything to do with the issue at hand, but to be sure, I'd test it out on a regular version just to be sure.

I didn't realize (or forgot) there was a regular portable version, so I have it running via portableapps. So I downloaded the regular portable one (4.3.0) and opened the file, re-extracted some text, saved, closed and reopened and the problem still occurs.

I also just opened the file using a fully installed version and still the extruded text loses its extrusion, so I must be missing some setting to maintain it.

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


text:
Problem with greyed out action editor

Action editor all functions greyed out, can't make or edit any actions.

Any chance the armature was linked from another blend file ?

No it was made in this file

Your action has been pushed down to NLA.
Go to NLA Window, select the action and press Tab to make it editable in the action editor.
Press Tab again when finished (hovering NLA window).


text:
Blender tool add ons
Does Blenders user licence allow for a user to integrate external tools to work the program into use in the construction industry,such as making add on tools

Yes, you can create addons as well as modify the open source code.

You'll find more informations here. Basically you can do almost anything you want to Blender. https://www.blender.org/support/faq/


text:
How to blend two objects into eachother?

I want to essentially create a smooth connection between object 1 and object 2, filling the gap without moving either one. How can i do this?

Hello, first thing join the 2 objects with Ctrl J then in Edit mode create a bridge between the 2 meshes?


text:
Object renders black

I've imported an .OBJ file to my scene and it looks good in viewport, but when I try to render with F12 it's completely black.
Clearing custom split normals data (in object data panel) removes black rendering issue, but also completely destroys the shading in viewport and render.
Is there a way to somehow retain the viewport like shading in render?

Can you upload screenshots/a .blend file to Blend Exchange?

Mesh has quite bad topology. I don't think it's possible to make the object smooth without retopologizing, like here.

The object is super smooth in viewport (because of CUSTOM split normals), but the problem is that for some reason those normals don't carry on to the rendered view.

I could retopologize but that model is actually only tiny fraction of my scene and it would take months from me to retopologize all. So I'm looking for another solution. Thanks for helping though! :)

I believe the sole purpose of those custom splitted normals are to avoid any retopology:(

You simply imported the mesh, and that is it. You have no lights in your scene. You (kind of) need a light to see your object. You also could use an hdr, but that is just complicating things unnecessarily.
For just a simple test render, or so you can see your object, a three point light setup will work (and make Gleb Alexandrov cringe).

You also need to turn off Auto Smooth for your object. There is something about the bad mesh (probably has to do with the normals) that is making auto smooth break.
Auto Smooth is found in the mesh tab of the properties window.

After the two changes I listed above, I rendered out your object like this.

Disabling auto smooth is no option as it uses those custom split normals which make the shading work in viewport.

Also without any lights it should still render gray not black as the horizon is default gray.

@user27158 the black rendering is because of the auto smooth.

Is there a way to somehow retain the viewport like shading in render?

@user27158 I have not used split normals, let along from an import. I do not know how to correctly display imported split normals.

I don't know much about normals in Blender, but they look pretty weird in your file.  Here's a section of your model, with a regular grid for comparison.

On yours, the vertex normals (dark blue) and face normals (light blue) are all pointing in, but the vertex-per-face normals (magenta) are facing out.  On the grid, they're all pointing in the same direction (inside/outside-wise).
I don't know enough to say that it's wrong (I wouldn't have even posted this as an answer, but I couldn't figure out another way to attach the image).  But it looks inconsistent.

No, they're not duplicate faces.  If I select one and hide it, there's nothing behind it.  Also, I deleted all of the faces except for 8.  The number of faces, edges and vertices is exactly what it should be.  The original mesh did have 390 duplicate vertices (out of ~1400), but removing them didn't change anything.


text:
Missing Open Shading Language in Cycle Renderer Check Box
Was reading up some interesting answers on animating noise. Until, I found out that blender 2.75 doesn't have the same interface as shown on the image below.
Does anyone know how to turn on Open Shading Language in the cycle renderer? Following the post here How to animate noise texture "seed"? I was not able to see the noise on screen at all. It outputs the noise as plain white.

OSL isn't available on GPU. If you are already set to CPU, it's possible your version of blender was compiled without it. Are you using an official build from blender.org? (btw, any particular reason for using 2.75? The latest version is currently 2.76)

Previously I had installation issue with 2.76 not registering properly so the blend thumbnail did not appear on the windows explorer. Yes I am running the official version from blender.org. I read on some other forum that OSL option was going to be available since 2.65 tho.

Yup , I can comfirm the problem was my default startup on the cycle setup was on GPU. Changing to CPU did made those Open Shading Option appear. Thanks.

Read about it in the manual but couldint find it in Blender, now I realized I needed to switch to CPU render first.

OSL isn't available on GPU. If you are already set to CPU, it's possible your version of blender was compiled without it. Are you using an official build from blender.org? (btw, any particular reason for using 2.75? The latest version is currently 2.76) – gandalf3

Now who is the joker that voted down the answer lol, wasting our time here to check.

I have set my options to CPU only on a machine that has two GTX-970s.  With CPUs off, there is no Open Shading Language available.


text:
Select Interior Face, how to make it work?
I have created a cube with interior faces all over the place.
The vertices and edges have all been collasped. Running the
Tool Select > Interior Faces ... does strange thing.
Does anyone know how this tool is suppose to work, cause it
does not seems to work as it's name implies. I have uploaded
a blend file, just in case someone could actually select those
interior faces with it.
Questions were asked here and here, but they do not
show why this tool don't seem to work at all.

You can download the blend file which is really small in size and try it out to see for yourself, basically it select a face on the outside of the mesh rather than the inside.

This tool is very limited. All it does is exactly in it's description:

Difference between an edge with 2 face users and edge with 3 (or more) face users:

All this tool does is for every face it checks if all it's edges have more than 2 face users. If yes, such face is selected.
This tool does not 'think' spatially and doesn't understand volumes at all. Here is an example when it will succeed and when it will fail:

@hawkenfox yes the name is unfortunate. Sadly lot of things inside blender could use additional programming so they work how you expect them to:)


text:
Why does my Eevee renders freeze at 98%?
I have here a strange situation today. On Blender 2.81 and 2.82, while trying to render a scene file, that I've been assembling for years, it strangely now keeps freezing at 98% and returns several "TIFFReadDirectory:Warning, unknown field with tag 18246 (0x4746) encountered"
...But I don't even have Tiff textures on the objects, they are all .png
...Some versions ago (from 2 months ago) render just fine, but from some point on, this error occurs.
Anyone knows what can be this related to? At least a clue?
It's surely not memory, I have a 12Gb Graphic Card (TitanX) and I can deactivate all collections (having just a few Mb of memory in use) and I still get the error.
Thank you very much for the attention!
Best regards,
Rogério

Edit: I've found the reason of the problem! It was some TIFF images loaded on a no longer existing object and the freezing at 98% was due it being render a 2nd ViewLayer that had all the objects turned on:

This view layer wasn't being used on the compositor and as such I wasn't seeing this render result in any place until now. Thanks for all the help!

The only reason for this warning is that Blender is trying to read a TIFF.
Objects are not the only things that might use TIFFs. You might check your skydome or environment texture. If you have BlenderGuru's Pro-lighting Skies, then it's probably loading TIFFs at some point. You may have some other addon that uses TIFF images.
If you can upload a copy of your .blend file, someone here might be able to help you track down what images are causing the problem.

Thank you very much for the fast reply! The .blend only has linked objects and materials from other files. I can, but It's a scene file that loads all the data from hundreds of other files. You would only see empties probably. As such, that means that the ghost TIFF may be coming with any of those... inclusively may be orphan data. Thanks once again, at least now I understand what the error report is! :) I'll report here as soon I find that TIFF.

Ok! I did had the TIFF images on some objects that no longer exist, but their data somehow was kept. Having removed all the TIFF images, that error report disappeared. The 98% render freeze still persists do, but this time doesn't report any error. Will need to investigate more.

I've found the reason of the freezing of the render. As it turned out it was just rendering a 2nd View Layer that had all the objects turned on :| Thus it would take forever to render that viewlayer that wasn't being used on the compositor. Thanks for everything Matt! :) I wouldn't have been able to solve this without your help!


text:
Curve deform - Follow along a path
Whilst searching for a solution I stumbled upon Animate object along path and deform accordingly
I am creating a logo for a new software project I am working on, the finished logo will have two dolphins either side of a infinity loop, I want these dolphins to be correctly deformed along the curve.
I will also create an animated 'loading indicator' with the dolphin moving arrond the loop.
I have downloaded a Dolphin from TurboSquid and getting it to follow the path is no problem, but I am having trouble with the curve deform.
It's difficault tweaking the Origin to be just right, I want the dolphin to be exactly along the path, but it is going all over the place.

The curve is not quite 2D:

On the Curve Modifer, deformation axis is set the X.
Am I doing something wrong?
Is there a better technique? Any pointers to tutorals?
Thanks. :-)
Update
Thanks guys for all your help.
I have had a little play arround with armatures and control objects, I have made a lot of progress but as you can see I have two issues:

The first bone (Bone02 in .blend file) seems to be stuck in position (it does have tracking constraint).
The mid-section (Bone05) is rotated causing the body twist.

(I have also updated the repo)

could you please share your file? (Simplify your dolphin if you don't want anyone to steal it)

@moonboots Thanks - I create a little GitHub repo with the files - One with armature, I don't know if that would be better - I have also just seen this video which maybe could help me

I thought you didn't have any armature and that you wanted to apply a simple curve modifier on an object. With an armature the solution would be different. Please tell me if the simple curve modifier could satisfy you?

if you want to use armature you might have your answer here: https://blender.stackexchange.com/questions/133012/line-of-bones-to-travel-and-conform-to-curve-like-train-on-a-track-snake

If you want to use an armature, follow the Batfinger's tuto here.
If you want to use a simple Curve modifier, you need to make sure that the position of your object on the curve. What you should do is:

Choose a vertex in your curve, where your animation is supposed to begin.
Make it the curve's origin.
Make it the curve’s first point. To do so, enable the Bsurfaces addon, select the vertex, in the Tools panel > Tools > Bsurfaces > click Set First Points.
Now put your dolphin object at the exact same point.
Move it on the right axis so that it follows the curve.


text:
X AND Y Directions in this Script
I got this script, which adds a slider in a tab for rotating Z axis.
i also want to rotate X and Y, so the user can adjust all of them.
how i can add these two axis to this code:
Thank you very much for you help :)
import bpy
from bpy.props import FloatProperty
from mathutils import Vector, Matrix, Quaternion, Euler
from math import degrees, radians

class HelloWorldPanel(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Hello World Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "object"

    def draw(self, context):
        layout = self.layout

        obj = context.object

        row = layout.row()
        row.label(text="Active object is: " + obj.name)
        row = layout.row()
        row.prop(obj, "name")

        row = layout.row()
        row.prop(obj, "rotate")

def get_rotation(self):
    return self.rotation_euler.to_matrix().to_euler('ZYX').z

def set_rotation(self, value):
    rot = self.rotation_euler.to_matrix().to_euler('ZYX')
    rot.z = value
    self.rotation_euler = rot.to_matrix().to_euler(self.rotation_mode)

def register():
    bpy.types.Object.rotate = FloatProperty(name="Rotation",
            description="Rotate object.",
            get=get_rotation,
            set=set_rotation,
            unit='ROTATION')

    bpy.utils.register_class(HelloWorldPanel)

def unregister():
    del bpy.types.Object.rotate
    bpy.utils.unregister_class(HelloWorldPanel)

if __name__ == "__main__":
    register()

Hi. Please only ask one question per post. You are welcome to ask multiple questions, but as separate posts.

Sorry Ray, i will delete one. :) hopefully the axis one get answered :)

Here is a proposal for the first question, without using the matrix conversion (not sure why it's necessary there?). Does it work for you?
import bpy
from bpy.props import FloatProperty
from mathutils import Vector, Matrix, Quaternion, Euler
from math import degrees, radians

class HelloWorldPanel(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Hello World Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "object"

    def draw(self, context):
        layout = self.layout

        obj = context.object

        row = layout.row()
        row.label(text="Active object is: " + obj.name)
        row = layout.row()
        row.prop(obj, "name")

        row = layout.row()
        row.prop(obj, "rotate_x")
        row.prop(obj, "rotate_y")
        row.prop(obj, "rotate_z")

def get_rotation_z(self):
    return self.rotation_euler[2]

def get_rotation_x(self):
    return self.rotation_euler[0]

def get_rotation_y(self):
    return self.rotation_euler[1]

def set_rotation_z(self, value):
    self.rotation_euler[2] = value

def set_rotation_y(self, value):
    self.rotation_euler[1] = value

def set_rotation_x(self, value):
    self.rotation_euler[0] = value

def register():
    bpy.types.Object.rotate_x = FloatProperty(name="Rotation X",
            description="Rotate object.",
            get=get_rotation_x,
            set=set_rotation_x,
            unit='ROTATION')
    bpy.types.Object.rotate_y = FloatProperty(name="Rotation Y",
            description="Rotate object.",
            get=get_rotation_y,
            set=set_rotation_y,
            unit='ROTATION')

    bpy.types.Object.rotate_z = FloatProperty(name="Rotation Z",
            description="Rotate object.",
            get=get_rotation_z,
            set=set_rotation_z,
            unit='ROTATION')

    bpy.utils.register_class(HelloWorldPanel)

def unregister():
    del bpy.types.Object.rotate
    bpy.utils.unregister_class(HelloWorldPanel)

if __name__ == "__main__":
    register()


text:
Does HDR sky resolution change a lighting?
I was wondering if I can use 2k/4k hdr skies instead of 8k but I want the best lighting and i don't know if the resolution changes anything so I decided to ask. thanks!.

Resolution of HDRi doesn't change strength of light too much.
Resolution have an influence on sharpness of shadows.
Probably not visible too much between 2K / 8K, but for lightning with 256px result visibly differs (see end of cube shadow). Small sharp point as light source (like sun) produce sharp shade, in small images it can be just a pixel, but usually is divided into several and also small image means bigger pixels in environment.
You can test it by your self if it matters in your case. Render them and if not noticable you can even try blend renders by Difference type to see per pixel differences.
Surprisingly for me it affects noise in render too.
Probably texture shoots light per pixel, so more pixels - more light rays ...? Anyway you would have to render with more samples fór lowres HDRi, than with highres HDRi, to get same quality.
In those two images I changed only HDRi texture resolution ... same samples.
256 px

8 K

Bigger issue can be a reflection.
... in case you have any visible in render.
256px / 8K

In case you need lowres environment HDRi texture for it's size, people use jpg version of HDRi in highres for just reflections. World node tree - Light path > Reflection Rays as factor.

I can't find the specific article of Greg Zaal, but you can check those as well Link1 or Link2.

thank you soo much vklidu this was really help full it really means alot <3

@ahmedabid Thanks for the Q. Noise was a big discovery for me, even I used  HDRi quite a lot  :)


text:
Why Cycles baking makes artifact lines to the texture?
For some reason when I bake diffuse color out from Blender, I get to my baked texture strange long lines and I was not able to find anyone else having similar problems.
The left one is the baked dice and the selected one is the high poly. Then I have a close-up view of the baked texture. In node editor, I have the high poly material.
UV-islands are not overlapping. Texture size is big enough that this should not happen because of it. The low poly object is not overlapping anywhere with the high poly.
Here is the blender file, if you wanna examine it better to see:
https://www.dropbox.com/s/sr5yeo1scf8g4bv/dices.blend?dl=0
I was using TexTools addon to bake, but I don't believe it to be the reason for this. I've seen similar lines before and I have slight idea that it has something to do with texture coordinates, but I don't understand enough myself to tell. Basically, the object coordinates is doing something "illegal" and I don't know what.
Can someone explain to me what is then causing these and how to avoid it in the future?


text:
How to rig a character where every element is separated?
I made a character where every element is separated as their own objects. (clothes, hair, eyes, tongue teeth, hands...) Should I join them to be one big mesh or keep them separated? How do I rig this and make weight paintings? I think automatic weights do not work probably. I have experiences that with autoweights I get for example jacket buttons behave in a weird way. Also, my knowledge of riggin is something in  these lines "Parent your object to bones with automatic weights and fix with weight paint". After that when I am able to pose my charcter with a very basic ways, I am thinking that the rig is "good enough".

You can for example parent any mesh object to bones with 'Empty groups' option and then in weight paint mode paint the weights for that empty vertex group

Thanks. I found one cool addon which I hope would be able to do that weighting part automatically so that I won't need to use too much time with painting. Still not tested it but at least now I have some hope: https://blendermarket.com/products/voxel-heat-diffuse-skinning


text:
How to remove rigid body setting from all the objects?
I have a big scene that I partly created using rigid body physics. I am happy with the objects now and I applied the visual transform, but I don't know a way to remove all the physics from this system now.
Joining the meshes sounds kind of a wrong "hacky" way to do it. In some situations joining meshes would be quite bad idea, because it would destroy your parentings and all that plausible other stuff that could be messed up with that method.
I can also make all the meshes passive simultaneously by holding ALT while doing it, but it doesn't remove the rigid body setting completely. If I try that same ALT clicking for the "rigid body" button, it doesn't do it for all the selected objects, only from the active.
So what is the correct way to remove rigid body physics from all the objects after you have applied the visual transform from them?

I found out that there is in scene properties the "rigid body world" checkbox which I can disable. It doesn't remove the rigid body settings from the objects, but I think it disables the rigid body functionality from the scene.

If you used rigid bodies and simulated to a point where you are happy with the positions, you can do the following:

Select all corresponding objects that are part of the rigid body simulation.
Press Ctrl+A Visual Transform

This will apply the objects visual transformation to it's data
Now you can essentially go to frame 1 and the objects will still be at the place you applied the Visual Transform.
With all related objects still selected, go in the Object Menu and under Rigid Body select the Remove, to remove the rigid body setting from all the selected objects.

After this is done, you have a still scene of the frame at which you applied the Visual Transform and the objects are no longer part of the simulation/Rigid Body World.
UPDATE:
A little demonstration using Blender 2.9, tested with 2.83 as well:

I'm aware that the question based on the visual transform already applied, but i included it, to have a complete solution for eventually others with similar situation.

Hi, this doesn't seem to work. Applying Visual Transform in step 1 doesn't seem to do anything at all regardless of what objects are selected. Scrubbing the frame slider back to frame 1 reverses the simulation. Removing the rigid body simulation at this point leaves you in the same state as before the simulation was run.

Updated the answer with a visual demonstration showing the steps and proof of it working. I made sure it worked in Blender 2.83 as well, since i used Blender 2.9 first.

Select rigid body objects run remove operator.
An object is a rigid body if it has a rigid_body property that is not None
is_rigid_body = ob.rigid_body is not None

See Select Active Rigid Body Parts
Script that selects objects if they are a rigid body of a certain type.  Once selected running
bpy.ops.rigidbody.objects_remove()

Will remove the rigid body settings of selected rigid bodies.
Disable the rigid body world
As commented can disable rigid body world.  Cam temporarily disable via
scene.rigidbody_world.enabled = False

The following worked for me and I did it 5 minutes ago (apologies to everyone if I am just too thick to understand you):

Run your simulation (hit the "play" button) and pause it when you are happy with how it looks.

Select AT LEAST the objects whose state you want to save. Other rigid bodies don't matter. Go to Object --> Rigid Body --> Apply Transformation.

DO NOT MOVE THE PLAY HEAD!

Go into the Scene tab (on the right) and first UNHECK the box that says Rigid Body World. THEN hit the button directly below it that says Remove Rigid Body World. This removes the rigid body constraint from everything in the scene. You might be fine only removing the rigid body constraints from the selected objects. That is supposed to be done via Object --> Rigid Body --> Remove but I messed up so many times before this while trying that, I was just happy to be done this way.


text:
Can't change Pose Position of Armatures to Rest with Alt-G,R,S combo
I just started using blender a few days ago and I've been tinkering around with simple armature models. In previous attempts, when I wanted the armature reset, I would do the Alt-G,R,S combo or 'Clear Transform' but now it doesn't seem to work. Is there an alternative option to explicitly replace the pose position with the rest position?
Ideally, I'd like to actually use the "Rest Position" Armatures for pose changes.
Earlier, I've tried to look for a method like this just to give an idea of what I'm trying to do:
1. Copy the Armature from the "Rest Position" tab
2. Proceed to the "Pose Position" tab, delete the Pose Position and...
3. Replace it with the "Rest Position" Armature so I can translate it since I'm in "Pose Position" mode.
That hasn't worked out for me and I'm stumped.
Edit: Nvm, just found out that the difference between resetting the "Pose Position" and "Rest Position" is that "Rest Position" doesn't take into consideration the effect of the IK constraints.

Enter pose mode, right click to open the pose context menu, and select "Clear User Transforms." In its options make sure "Only Selected" is unchecked. This will clear all pose on the armature, including unselected or hidden bones.

In the properties panel, under the armature settings you can reset the pose to the rest position by selecting "Rest Position."

The problem with that is I can't change poses when "Rest Position" is enabled.


text:
How to remove all only rotation keyframes from current action with Python?
How to remove only rotation keyframes from current action with Python? Or location keyframes? Or scale? Is it passible?

Related

Using FCurve.remove
The curve, as shown in graph editor,  with keyframe points for each keyframe value pair is an fcurve.  Removing an fcurve Will remove all keyframes for that FCurve.data_path, Fcurve.array_index pair
Similarly to this related (possible duplicate) question.  Example script removes all Location, Rotation and Scale fcurves from an action.  It tests the FCurve.data_path against the keyframe type list ["location", "rotation", "scale"].  Note "rotation" will match "rotation_euler" or "rotation_quaternion" etc, which will be the actual datapath (as there is no Object.rotation).
Avoided using the FCurves.find method with a list comprehension, and used pop to avoid possibly referencing a removed fcurve later.
import bpy

context = bpy.context
ob = context.object
ad = ob.animation_data

if ad:
    action = ad.action
    if action:
        remove_types = ["location", "scale", "rotation"]
        # select all that have datapath above
        fcurves = [fc for fc in action.fcurves
                for type in remove_types
                if fc.data_path.startswith(type)
                ]
        # remove fcurves
        while(fcurves):
            fc = fcurves.pop()
            action.fcurves.remove(fc)

To remove only y axis Loc, Rot and Scale also test for the Fcurve.array_index property which is 0, 1, 2 for x, y, z respectively.
        fcurves = [fc for fc in action.fcurves
                for type in remove_types
                if fc.data_path.startswith(type)
                and fc.array_index == 1
                ]


text:
Compositor and rendered image not the same
I have set render layers, combined in compositor.
Post processing is checked for compositing.
the rendering rendered all 3 layers but the final outcome is only one fo those layers.
the viewer and the final render is different.
(something that is weird: i tried both cpu and gpu to render, previously does not have this problem but recently when i render after the 1st layer, the img of the first layer is still visible while rendering the second layer, only "overwrite" when the boxes render the portion, i wonder if it is a bug...)

pls provide us your blendfile (http://blend-exchange.giantcowfilms.com/) or upload some screenshots of your compositor. otherwise your question is to vague and can be caused by several reasons

This is because in your file, the image viewer is set to display the "Bangle" renderlayer:

Select "Composite" instead to view the output of the compositor.


text:
why is my displacement map not sharp?

The displacement map is an animation of the letters being engraved in the metal. The animation itself works just fine. The only problem is the edges of the letters. How can i get them straight instead of this?
-I tried a higher amount of subdivisions but that doesn't seem to work (blender crashes).
-I am also pretty sure it has got nothing to do with the animation i made in after effects.

Do you have Displacement modifier on top of your modifiers stack?

Increase the subdivisions and also check if their value for "Render View" is set at least to the same amount than it is in 3D view.

@PaulGonet , I only have 1 modifier and that's the displace modifier.

@metaphor_set, If I try to open the subdivisions 'tab' ( by going into edit mode> 'w' > subdivide) blender crashes. I think the last image I uploaded explains why.

Instead of a "normal" subdivide I'd always go with a Subdivision Modifier or a Multiresolution Modifier. They won't change how subdivision works but at least they are non-distructive as long as you don't apply them. Nice clean letters could also be done by importing them as curves and using the extrusion method. It's a little more work but the result is much better imho.

What's the resolution of your displacement image? A low resolution map could be causing that too.
Try again with another copy of the image saved in very high resolution (and preferrably in 16bpc with a pinch of blur to produce glentler edges.

@Gez , Thanks that could be it, I'll check it out!

I would suggest download the latest Blender build https://builder.blender.org/download/ (2.78)  and use the new microdisplacements feature. I tried this with creating a gold seal and it looks very good with not much work. I would watch this tutorial to understand it better. http://www.blenderguru.com/tutorials/introduction-microdisplacements/


text:
Round corners of plane wing
I want to round the edges of my wing, so it will fit the blueprint. I have tried the Bevel tool, but it does not work in this situation.

Is there any easy way to do this?

In edit mode, select only the central vertex and enable proportional editing, sphere falloff, adjust the effect with central mouse wheel and grab (in my example along the X axis).


text:
Light object evenly and have a transparent or solid background
I am trying to generate a 2d image dataset form a 3d model rendered in Blender. I want to randomize the orientation of the object, the lightning and a background image.
My idea to randomize the lighting is to have a light aiming at the object at a fixed distance (radius) but otherwise positioned randomly around the object. By doing that I foresee a problem: there will be very strong shadows. The scene contains only the object, so there is nothing to reflect and spread the light.
How could I solve that? Would it work to have some "general" lighting and then have this other moving light in a way that all faces of the are never in absolute darkness? Is there a method (best practice) to lid and object quite evenly? Is there a certain type of light that spreads more than another?
Another important point is that the background of the rendered image should be either a solid color or transparent in order to replace it with a background image. Shadows on the background would be a problem.
And last thing to mention: I am just getting started with blender. So please tell me if you think I am trying to do something stupid or in a very wrong way. For example I am not sure if it makes to have a scene with only one object or it would be better to try to recreate a room scenario were the light is reflected in the walls more naturally.
My model
This is my model from 3DXtras and below is a render of it. This image shows  pretty much the kind of lightning I want to achieve but with an solid colored background if possible.

Check this: http://blend-exchange.giantcowfilms.com/b/1970/ and tell me what I should explain to you in answer. It's HDRI map as environment, plane with emission as light connected to circle above object and curved plane as background.

So is the question about how to randomise lights or is it just how to get even lighting?

How to get even lighting primarily. For the randomization I think I can manage but suggestions are welcome

@LukeD Thanks for your link, I have a few questions. First I didn't understand the source of light, but I figured it's World => Surface. Does that lid everywhere evenly? Then didn't understand the reason for the BeizerCircle? Removing it doesn't seem to affect the render result. I also removed the Plane to obtain an even background. And finally I figured I can use Plane.001 to randomize the light, I am not sure how that is better than having a light object insted. Plus if that plain would be in the range of the camera it would be rendered as well, wouldn't it?

Plane connected to circle behave like an area lamp, it allow you to change lightning as you describe you want to do it, yes it will be visible in render if positioned so. Secondly World > Surface is Environment map (HDRI) it is simulating photo studio ligthnig so it light evenly as much as what type of map do you use for this.

I would suggest removing some of the 'context' for the question as knowing what you are going to be doing with the lighting doesn't really effect the base question of 'How do I evenly light an object?'.

In General
The ultimate purpose of every 3D render engine is to create 2D images of 3D objects in a way that they are recognizable as 3D objects. A main aspect of this is light - and therefore also shadows.
Depending on how realistic the source images are and how exact your image recognition software should work, keep that in mind.
Transparent Background
Guessing from your rendered image, I assume you are using cycles. To get a transparent background, just get rid of the object that generates the white plane(s), then go to "Properties Window - Render - Film" and mark the Checkbox for transparent background.

Light Setup
If you use Cycles instead of Blender internal you can avoid hard shadows to a point where there are nearly no shadows at all. Because it handles light "more naturally", it's really simple to recreate a diffuse light setup similar to what you would use in a photo studio setup.
Instead of a common light source, you can use planes, assign a light-emitting material to them and turn off their ray visibility. This method gives you more "visible" control over your light sources.
Depending on the plane's size and the strength of the light your shadows will get stronger. If you add more than one plane you can get to a point where there is nearly no shadowing at all.
Here's the result with one light-emiting plane:

The same scene with six light-emiting planes, that are placed in even distances around the object:

Remember to turn off the camera ray visibility for your light planes.

Here's the .blend that contains the setup.

I have complemented the lighting setup from @metaphor_set's answer with a Blender script that randomizes the lighting intensity and position around the object. The purpose of the script is to generate an image dataset from a 3d model with N unique images. Feel free to use it to generate your own image datasets.
Download the project file:

Examples:


text:
Is there a way to automatically create new material in all meshes in the model?
is there a way to automatically create new material into every mesh of a model?
I have this issue with auto-rigging from Mixamo as it removes the existing materials when I download the rigged model. So I have to remake the materials again when importing the auto-rigged model back to Blender.
I don't mind if it assigns only the default Principled BSDF. I just need containers to put the shaders in when I import the model to Unity.

i) Do you have the blend with the materials pre-mixamo, and ii) are there more than 1 material per object, iii) if so, does the mesh still have materials  assigned to faces?

No, Each mesh has only material in it.

I am not sure if I understood the question correctly, but If you want to assign the same material to all objects then select all objects, click on the Object you want the materials to copy from (it gets highlighted in yellow) then press "Ctrl L" and choose Materials. All objects should share the same Materialdata then.
If you just have one model with different textures on it, go into edit mode select all vertices choose the one material you want to copy in the material bar on the right and press "assign" under the material options.

I'm sorry... I think I messed up my terms. What was actually asking is if there is a way to automatically create new materials on every single mesh in a model.

you can do this via python like this:

move all your objects which should have a new material in the collection named "Automatic" -> or change the python code to the name whatever you want

run the script
 import bpy

 def create_material(object):

     newMat = bpy.data.materials.new(name = 'Material')
     object.data.materials.append(newMat)

     newMat.use_nodes = True

     nodes = newMat.node_tree.nodes

     material_output = nodes.get("Material Output")

     node_emission = nodes.new(type='ShaderNodeBsdfDiffuse')

     node_emission.inputs[0].default_value = (1,0,0,1)

     links = newMat.node_tree.links

     newLink = links.new(node_emission.outputs[0], material_output.inputs[0])

 index = bpy.data.collections.find('Automatic')
 coll = bpy.data.collections[index]

 for eachObject in coll.objects:

     if len(eachObject.data.materials) == 0:
         create_material(eachObject)

okay, so where do I run this script on?

To run the script:
Start Blender and switch to the Scripting workspace.
Click the New button in the text editor to create a new text data-block.
Copy the code from above and paste it into the text editor.
Click on the Run Script button.


text:
Moving armature-bone moves the whole character
I just set up a character rig and am trying to animate it now. However, when I move this one armature it simply moves the whole character but the mesh itself doesn't move. When I try to rotate this bone it also rotates the whole character.
Here's a photo of what I mean: https://i.sstatic.net/X5H6r.jpg
What it's supposed to do: https://i.sstatic.net/1CwVz.jpg

How to upload an image to a post

The bone is doing what it's meant to be doing; there's nothing wrong with that. The difference is that in the second image the legs have an IK rig (shown by the yellow bones on the shins of the legs), meaning that when the body moves it will bend the legs accordingly. You'll need to set that up and then you should be all good.

Oh my god, thank you so much! I feel really silly for asking this question.


text:
issue with grease pencil and tablet pressure
After creating a new 2d animation project i started drawing with my tablet (xp-pen artist 12) and i noticed this:

as you can see the newer line is covered by the older path.
I don't know if this is just a default setting or a bug but i couldn't find anything about it.
This happens with the tablet pressure strength option enabled in the brush settings, without it the stroke has the same color and this isn't noticeable.
With the same tablet i don't get this using other drawing apps like photoshop.
How can i solve this?

It looks like a bug, you should report it as a  bug. Help -> Report a Bug.

It is the same with Wacom Intous tablet.

For those Who are interested i submitted a bug report and got a solution:
It is a stencil setting in the stroke panel, to disable this the feature Is "self overlap".
Blender stencil setting
Credits antoniov developer for clarification.

Don't forget you can self-accept by clicking on the checkmark by the voting buttons.


text:
Scaling on X axis changes XY axis angles
Change basic cube to a board shape, Z=.1, X=8, Y=.4. Edit mode; grab back left 2 vertices along X axis for a 60 degree angle on the left side of the board. Select all vertices, and do Mesh - Symmetrize - -X to +X. Now the other side looks great, too. Duplicate object. Scale smaller only on the X axis. Results is the 60 degree angle is now less than 60 degrees.
Why? Why didn't it make a shorter board with 60 degree angles on each end? Why did it not scale the back vertices the same distance as the front vertices? Is there a way to make it scale both the back and front vertices at the same time the same distance along the X, (or any), axis?
I tried "Delta Scaling" and got the same results. It seems to apply a percentage of distance, instead of the exact distances I provide it, thus distorting the shape.In other words, (and using different figures ... not the ones above), a 1 meter box with the front left at 1 meter, but the back changed to .8 meters, when scaled from 1 meter to .8 meters will take 20% off the length of the front, and 20% off the length of the back, instead of taking .2 meters off of both, as expected.
These angles don't change when the entire object is scaled, (vs. just one axis), using the Scale command, but it does when entering the exact values into the Transform tab, where one axis at a time has to be entered. Why would it do it differently for a single axis?
EDIT
It was wrong of me to expect someone to build this to see what I mean, so I made some screen shots:

Scale will change the angle of angled edges when scaling by 1 axis, that's what scale is. If you scale by all axes at once obviously object won't be changed but not if by only 1. It's the same as if you select one of those angled edges and scale it by X axis.

Seems to state what I showed. I guess the question I meant to ask is more about how to get around this "feature" without having to take each object into edit mode after scaling.

Workaround is to use Hook modifier and hook each face to new empty, then scale empties. https://blender.stackexchange.com/questions/63906/move-multiple-faces-towards-single-point. If working with geometry grabbing those faces is the tool to work with, not scale. Another one could be Edge Slide with limits turned off (select face, press G twice and hold Alt, at least those were shortcuts in 2.79)

Thank you. I will try that. I noticed one comment on that link about it being a tedious process. What I've had to do instead is a tedious process. This one you point me to looks smoother and more accurate, so, tedious or not, that alone is worth it. Um, but it'll be awhile before I can try it. Halloween stuff is tying up my Blender right now.

As Mr Zak has said: if you scale a trapezoid board lengthwise, the angle of the skew end is modified. Would it perhaps be possible to use the Boolean modifier to cut the ends exactly?

That's not a bad idea. Instead of creating each "board" as mere copies of the first one, instead of doing just a Duplicate Object, to do a Duplicate Linked, then turn another cube object to the proper angle, and BoolTool Difference all of the "boards", and repeat on the other end of the "boards".  Seems easy, and I really don't need any of the "boards" as seperate objects. Should work. I'll try it ... someday. (Got some security fires to put out before I can take time for Blender.)

Tschöbbel had the right idea. Rather than create a "board" with each end "trimmed" at 60Deg, and then duplicating and resizing each "board", I created the first basic "board" with straight ends, and did a "duplicate linked" on that "board". However, the next step is to "join" all of the boards into one object. After that I was able to use 2 cubes turned at 60Deg and -60Deg on each end of the "boards", and did a "BoolTool Difference" to "trim" all the ends of the "boards" at 60Deg, creating a "panel" of "boards". I then duplicated that 5 times, and rotated the "panels" into place for the hexagon "floor" of my "gazebo". It worked very fast.
Thank You, Tschöbbel!
Also, I'd like to thank everyone else for your help. The other suggestions were just as likely to create equal results at less time than I thought I was going to have to spend, but the Tschöbbel answer was really fast. That method is going to make doing the "roof" of the "gazebo", (with overlapping "slats"), very fast and easy, too.


text:
How to make inside corner smooth?

I want to make this smooth as per the black line

You can :
1- subdivide the edge

2-Move the new vertex inside the face

3-Bevel the vertex with CTRL Shift B


text:
How do I quickly and easily scatter these individual cubes away from the center, without having to separate them by loose parts? It's one object

This Rubik's cube as a whole is one object made up of 27 loose cubes. I have animated a previous section where the initially scrambled cube is solved by rotating the cubes in edit mode and keyframing them with the anim-all add-on. What I now want to do is have the cube "blow up" by scattering the cubes in different directions, away from its center. Is there a way for me to quickly achieve this without having to separate by loose parts or keyframe each cube one by one? I tried using the push/pull operator, but all this did was warp individual cubes instead of moving them around. Thank you

If you need separate parts of an object act as separate objects, the easiest solution is to just separate them into separate objects. So you should have done that in the first place before animating.
With that said, you are in a situation you are now and it's still possible to make separate parts act like separate objects. That is possible to do in a few ways. One way would be to use hook modifiers and hook each cube to a separate object. You can do that by selecting each cube's geometry in edit mode and hitting  Ctrl  +  H  and choosing Hook to New Object. The issue is you have to do that 27 times. Once you have the empties, you can animate their locations. It's easy to move them apart by scaling them
with Affect Only > Locations enabled:

You can also animate the Strength of the Hook modifiers and set them to 0 for the part where you don't want the empties to have any effects and let the cube be animated other ways.

There is also nothing wrong with hiding your cube at some frame and switching it out to a duplicate, that looks the same at that frame but consists of separated geometry that is set up in completely different way. You could do physics simulations this way for example while keeping your existing animation before that made another way.


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Best options for good quality and quick rendering of long animations
I have just completed a 50 second animation that uses a HDRI sky as well as various other lights. I am using the cycles render engine. I am not new to blender but do not have any experience rendering things. I have seen people pump out great looking animations, but I always wonder how they are able to do it without it taking weeks to render. I believe I am doing something wrong.
My animation does make use of the HDRI, it is a city at dusk but it switches to interior shots (which looks onto the outside street). Is there any alternative or optimisations I can make, or should I just start looking into render farms.
I can link my animation project if needed. Any suggestions regarding optimising will also be welcome. (Including materials)
Thanks

Hi I believe the linked post shoulbd broadly answer your question. If you have any more specific questions or particular concerns, please edit your post and rephrase it to focus on the particular aspect you are having difficulties with.


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Problems with the videoeditor and rendering PNG animations
I am currently exporting a 1205 frame animation that was rendered in PNGs, I would like the exact render image to be converted into an MP4, but I have tried a range of suggested settings, different formats etc (including the most suggested: FFmpeg, MPEG-4, H264, perceptially lossless, etc. But whenever I exported the animation in the video editor I got a lot of artifacts in dark scenes due to the compression. I then changed the output quality to high quality and all the artifacts were cleared up but now the animation lighting is completely different.
I am very new to rendering but not to blender in general. Could someone help me understand what is going on, I have spent many hours trying to fix this and I am having no luck finding anything on the internet as it differs from case to case.
Thanks

Are you referring to the problem described in this video?

Yes, but i fixed it using high quality output, but when i changed it to this setting the light areas remained normal but the dark areas just got super dark. I just dont get why the blender editor is changing the way the frames look, surely there is a way to export a collection of PNGs so it looks the same as you render it.

Can you show where you change the “high-quality output“ setting? I’m not familiar with it. Also please show examples of the input PNG’s and a screenshot from the two output videos.

Also show a comparison of a frame before/after video encoding. Make sure you use the appropriate Color Management in your scene and on your VSE strip.

...actually, if the PNGs are rendered with Color Management which I suppose, then you probably have to render the video sequence without any Color Management on top of it, i.e. it should be set to View Transform > Standard and Look > None.

Hello, so the actual render is fine, but its just combining it to an mp4, the pngs are set to "follow scene", they are set to RGBA, 16 colour depth, 0% compression. for post processing they are using compositing only and 0 dither. I am just stuck on what settings to use for converting to mp4 without losing any quality and keeping it exactly as it looks in the png.

For the conversion to mp4, i am converting to ffmpeg, RGB, MPEG-4 encoding, H264 codec, lossless quality with good encoding speed. keyframe interval is 18 (which I dont know what it does) and post processing is using sequencer and 0 dither again.
I am using the exact same resolution and aspect ratio, as well as the FPS as the original animation.
Below is a picture of a frame when converted to mp4 vs its original render.
https://gyazo.com/9b09e491fb166b135813c025b7eadaa7
https://gyazo.com/8e31fab0abac527311bf0f82312d074b

You can see there is a lot more noise. I have spent a lot of the day trying to figure out different combinations of settings but most of the examples of the different settings have been overriden as i have used the same directory for the outputs.


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Beveling and bevel bodifier
I have applied mesh and also scale and location of my model is zero still after applying bevel modifier it is not showing any effect of beweling ,i also gone to edit mode selecting all and tried to bevel through ctrl+ b it is destroying the model

Hello also recalculate the normals in Edit mode (Shift N), but maybe show a screenshot or even share your file


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node editor - How to set the glow color differently from main on emission
I am trying to make a lava-like glow texture with emission. I want the main part of the object to be yellow, but the surrounding glow to be orange. However, when I use the emission with Bloom in Eevee, the object always becomes a very bright white or pale color and turning down the strength barely helps as when the color becomes more saturated, the glow is lost already.
Here is the WIP model:

Here is the node setup:

Have you tried just using red or orange instead of yellow?

Well, yes, but the problem still remains - the color of the object itself is highly desaturated. And, as stated, I wanted the color of the main object to be yellow while the glow to be orange.


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Making a pineapple
Do you guys know any good ways of making a pineapple in Blender? It can be low poly and cartoonish. So far THIS is best i got

LowRes https://identity.trimble.com/commonauth MidRes https://www.turbosquid.com/3d-models/free-max-model-pineapple/741563 HiRes https://www.the-boundarystore.com/products/pineapple

Way better I could do it. Why don't you like your result?

So... hi poly.

The leaves are done with an array modifier driven by an empty a bit scaled down, rotated and shifted down.

The body is an hexagon inside of which the pineapple skin is modeled. It is a bit stretched as will need to make it more oblong later.
Then use 3 arrays to have an hexagonal map:

Now we need to make that spherical, and we can use this answer to do it.
This is two simple deforms and a lattice to make it more tubular/oblong:

The sequence of modifiers:

PS: I know there is a gap at the edges of the second simple deform modifier. That will be possible to join it with the weld modifier in 2.83, using a vertex group. For now in 2.82 the weld modifier does not take the vertex group into account.

Can you describe the process of making the hexagon? Or point me to a link?

@Strawberry, to make a base hexagon, just add a circle and change its vertices to 6. From that here i've simply extruded and scaled down.

I get that part; it's what happens next that I'm struggling with! Ah, extruded and scaled down - let me try that

The best to see what is happening (from the blend file in the answer) is to disable all the modifiers (disable, not remove) then reactivate them one by one (like in the gif above). So you can see how it works step by step.

Low Poly

add Cylinder
in edit mode Loop Cut Ctrl+R
search Un-Subdive > 1
Scale down top and bottom part to shape oval

Triangulate Ctrl+T (but not necessary), for horiyontal split I scale it verticaly so blender use the shorter (horizontal) direction between vertices
for leaves - Extrude E / Scale S top vertices, Subdivide W and Scale down

That's actually quite a cute pineapple. But I have one question: If I look at it from the top or bottom, what will I see? Will the top just be green or the pineapple color? And the bottom? Is it just a pineapple-color "base"?

You will see what you make :) Yes I could left it filled and extrude, it make more sence - manifold mesh. It was just a quick test, I did not expect such interest on this topic.

I'm sorry, but I do not understand your comment. Could you please rephrase it?

WORK IS REALLY AWESOME DUDE

@IsmaelMiguel I dont understand your Q. It depend on you, how you will model your. Now there is a hole (because I delete top face as you can see), but you can keep top face when extruding "green" so like that it stay green from top, that is more natural.


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An object inside in another object with physics properties - rigid body
I am trying to create a physics simulation, but I not succeed...
What settings should I use for rigid body if I want to create an object inside in another object with physics properties (rigid body)

After I click on play the simulation goes wrong...

Now the bottle is intersecting or passing through one another ...
I have tried:

checked the normals
keep the real life proportions (size, weight...)
applied all transforms for scale, position and rotation
set Origin > origin to geometry
increasing the Steps per second and Solver Iterations in the Rigid Body World settings (I tried with the maxima 1000 and 100)
set collision shape to Mesh and tried 0.4 or 0 as margins and source to final

Please (next time) use https://blend-exchange.giantcowfilms.com to share your files. Thank you

For those who come here with this problem try setting the shape of the collision to mesh for the outside shape.

For your problem, I set the collision shape to convex hull for the inner bottle and it reacted normally. I don't know how attached you are to that setting but that might do it.

@diniulian I suggest this as the correct answer. Of course the other provides a solution, too - but changing geometry for physics, rendering with a different model parented to the rigid body etc. is too much effort if it works with a simple change of the Collision Shape. Physics work better the more basic the collision shape is. For example, with the cube set to Box you don't need much geometry. Mesh is the shape I use least, only where Blender needs to know there might be an object within the bounding geometry of another object, e.g. chain links or things like that outside bottle.

Oh, and if there are still problems since your bottles are not very large objects, you might try to set the Collision Margin of the outside bottle from 0.01 to something like 0.005 or 0.001 - but actually there's no need to do it in this example, after you've set the inner bottle to Convex Hull it works as it should.

@gordonbrinkmann - fair comment about it being a simpler solution, although it isn’t appropriate to all situations. Using Convex Hull does simplify the collision detection and is likely helping since you’ve then effectively got a solid bottle within the outer one - instead of thin surfaces colliding with thin surfaces and risking passing through, Blender can determine that the section of outer bottle is intersecting and push the surfaces apart in the correct direction. I guess both solutions need to be kept in mind but happy this one is the new accepted answer since it is simpler.

But it's not "thin surfaces colliding with thin surfaces", the bottles have outer and inner faces and the directions in which to push them apart are clearly determined. But since there's nothing inside the smaller bottle, using convex hull on it is completely sufficient. In case it still doesn't work you can increase the number of substeps. Of course this does not apply to every possible rigid body animation, but it serves best for the given question since it works without error, is adequate for similar situations and you don't have to rebuild or add objects or anything like that.

The problem is with the outer surface of the geometry being too close to the inner. This is causing points that collide with the inner surface from being confused as to which side of the thin glass they should be repelled.
The solution is to simplify your collision mesh so that it only includes the 'inner' surface - with the normals all pointing inwards. This allows Blender to treat it as if it is a bottle-shaped cavity in a solid block of glass so that it is obvious which direction intersecting vertices should be repelled.
I took your example and simply removed the outer faces of the larger bottle and set the number of simulation frames per second to 240 and produced this animation :

For rendering purposes you should create the actual outer bottle and set up the collision collections such that it is not included in the collision of the smaller bottle. The collision mesh (consisting of just those inner faces) should be parented to the actual outer bottle so that it follows the outer bottle and provides the surface for the inner bottle to react.


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TIFF alpha channel glows on edges
When I try to use an image that has an alpha channel, the image has glowing around the parts where there is transparency. Below are images to better explain my issue. Both are using the same image with exactly the same node setup and Cycles render engine.
In Blender 2.90.1 it looks like this:

and in Blender 2.79 it works as expected:

This is the image i'm using. It is a TIF file created in Photoshop

Is this a bug or has something changed in the way alpha is handled?
I haven't used 2.90.1 version for long as I only recently updated from 2.79
EDIT: After packing the TIFF file into the blend file, the glowing disappeared. Then after unpacking the image and adding it to a new image texture node, the  glowing appeared again.
Looks like Blender 2.90.1 treats external and packed files differently.

Hello :). What happens if you plug the alpha channel directly into the Alpha input of Pricipled BSDF? And don't use the mix node?

Hi. The result is the same.

I would suspect that for some reason the input values are larger than 1.0. Could you try to add a Map Range node with Clamp enabled between the Image node and the Principled BSDF? Does the glow also occur when only the color is connected?

I added the map range node with clamp enabled. The texture turned grayscale as expected but I could still see the glow around the holes like before (just not so bright as it was only grayscale). I also tried to connect the texture color to the Principled BSDF and disconnected the alpha socket of the texture node completely, after that the glow disappeared along with the transparent holes.

Photoshop has completely bungled alpha. All of Blender’s eight bit imports are unassociated, so I suspect it might be interpreting the TIFF incorrectly as unassociated alpha and it is associated? On the upside, Blender finally displays alpha properly thanks to @atmind.

I'm sorry, I got the versions mixed up big time. I corrected the question now. I also downloaded 2.91.0 Alpha from builder.blender.org and tried my blend file there but the behaviour is still the same as 2.90.1; there is no glow when using a packed image but after extracting and re-adding the image as an external image, the glow appears again.

@troy_s Now I'm going to be interested what is going on with TIFF when packed into a blend (that is fine), but unpacked issue is back. Why blender reads same data differently? Thank you

As @troy_s sugested, it's important to determine first whether the TIFF has an associated or unassociated alpha (the format allows both, although Photoshop internals are unassociated).
If alpha is misinterpreted, you'll get either double association (dark fringe) or a misplaced division (producing those glowing artifacts). Older blender versions used to assume that 8 bit RGBA images were always unassociated sRGB, usually matching the output from Photoshop. Blender 2.91 might have changed that.

Leaving aside changes that Blender 2.91 might have introduced, it's important to note that Photoshop offers different and incosistent ways of saving a TIFF: If you keep layer masks in your source image, it will save unassociated no matter what. If you apply the masks, it will associate if you mark the save transparency checkbox in the exporter, and save something that Blender won't interpret as RGBA if you don't.

Also important: keep in mind that Photoshop apparently associates alpha when you mark the Save Transparency checkbox ONLY when you're not using layers/masks.
When you keep masks, the resulting tiff will still be unassociated (straight).

With image packaged into blend it works for me as expected. The issue appears when TIFF is unpacked and used linked from directory. Troy_s probably will be able to explain the issue, I don't have a knowledge in this area. I can just say how to avoid the issue here.

your TIFF doesn't use Transparency but channel "Alpha" (that is also why option "Save Transparency" is grey when you are saving your TIFF

to avoid the issue copy alpha channel and paste into Mask channel for "Background" layer.

Then when you save with "Layers", "Save Transparency" is available.

This TIFF is rendered fine in Blender.

Here is an image of my TIFF save options: imgur the save transparency option is grayed out for some reason but the "Save alpha channels" option is enabled in the "Save as" window that appears before the TIFF options window. Color space is RGB and bit depth is 8bit.

I attached the blend file to the question now.

This method worked and now the transparency works in Blender. Though its weird that saving the image from photoshop and using the alpha channel instead of a layer mask works when the image is packed into the blend file. This sounds like a bug and should be looked into.

As Troy_s commented it can be on Photoshop side, I don't really know how these things works. Also Robert's comment is right, there is RGB larger than 1. So it is definitely clear Alpha channel participates on  RGB appearance. I'm more curious how blender handles packed  TIFF without issue ... :)

I might be wrong here but it seems like Blender treats the alpha channel of external images as premultiplied alpha regardless of what has been chosen in the properties panel. If you read here in the Blender docs it says that premultiplied alpha is useful for emissive effects and that sounds like what is happening here with RGB larger than 1, causing the glowing effect.

It used to be the other way around. Blender used to assume that 8bit images with alpha were unassociated, which made dealing with associated tiffs problematic.
Maybe (and I'm just speculating because I'm not using 2.91) Blender finally does the right thing and reads the tiff Metadata to pick the proper association instead of assuming it's unassociated. That would mean that an unproperly tagged image coming from Photoshop might break.

Another possibility is that they changed the tiff importer to assume it's always associated, which would result in missing a multiplication when an unassociated file is loaded.
If the texture's alpha dropdown doesn't do anything when you switch from premultiplied to straight that might be the problem.
Again, pure speculation. You need to figure out first whether the Tiff file is correct and whether alpha is associated or not.

I'm thinking that the only way you can see those glowing edges is that you feed unassociated to the shader and interpret it as associated (skipping multiplication). But in your screenshots we can see that your alpha is set to straight.
If the file is actually unassociated, then it's clearly a bug, but you have to make sure that the file is right.

I changed the Alpha dropdown to channel packed and that got rid of the glowing effect when using external image. How can I figure out if the Tiff file is correct?

@nyaol9 if your intention is to use a texture with transparency, ignore the "channel packed" option. It's intended for something else.
There are two methods of encoding alpha: One is as a separate mask. We call that "Unasociated alpha", because alpha is completely independent of RGB. It is also often called "straight" or unpremultiplied".
How do you tell an image is unassociated? Pixels that should be completely transparent show colour in the RGB channels, therefore the alpha channel has to be multiplied to the RGB channels don't contribute any colour.

The other method (which Blender produces when it renders a 3D scene) is "associated" (often called premultiplied). There's a relationship between RGB emissions and alpha. Completely transparent pixels will be black in the RGB channels as they don't contribute any light, but you may find colored pixels that are supposed to be transparent but still contribute light (light fire, glows, light beams, etc.). In an associated alpha image, if you inspect the RGB channels of pixels that should be completely transparent, you'll find black.

So the way to tell if your image file is whether Associated or unassociated is to figure out if RGB is tied to RGB: If it doesn't, and it has to be masked to be used, then it's unassociated (straight). If it's ready to be composited and transparent pixels don't add any light where they shouldn't, they are associated.
Keep that in mind to choose the right alpha type in Blender and you should be fine, unless there is a bug.

@Gez I really appreciate your insight, but as you can see these comments are character limited, for a reason. Please delete your comments and summarise them into structured answer. Thank you for your help to keep site readable.

@vklidu I didn't provide an anwser yet because it's not clear whether the behavior is caused by a Blender's bug or not. I tried to guide the OP so s/he can figure out the source of the problem instead. I don't think it's completely clear yet. If you think that my answers are clear enough to solve the problem, feel free to summarize my comments into an answer and I'll delete these comments.

@DuarteFarrajotaRamos is it possible to move it to chat? Would it be accesable to user with a low credit?


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Distribute points on grid geometry nodes
I'd like to do something like on picture windows are distributed on face height and length also on angled faces. Any ideas ???

Update: Is it possible to convert it to 3d space

I think @vklidu actually answered your question well, and his technique works well with a grid. What you want to do with your update is a completely different question, in my opinion.

I agree probably better to ask a new question ... I wanted to offer "array" grid in Z axis and use "Mesh Boolean" node, that works kind of, but it generates extra vertices. https://imgur.com/Dw4S0qO ... And Boolean grid as vertices doesn't work at all. Hmm

Did you ever find a way to do this in 3D? I'm trying to select points by proximity to the face of another geometry node primitive and cannot figure it out.

Here is kind of working ...

Plane object as base mesh
Grid primitive node for points distribution in larger area
All points inside the Plane are taken by Geometry Proximity node > Face as Selection factor for Instancing.

Tip: With this math you can easily extend grid by single value (integer) in meters ...

If for some reason scaling was not enough, could you do some attribute trickery where all instances not in proximity don't get an attribute applied, and then you do some sort of selection where only the ones with the attribute are kept?

@Ben I'm not sure I understand ... have you noticed my note under node tree? You can use Proximity for Selection (instead of Scale).

I had in fact missed that note.  Thanks.  Still get tripped up by geometry nodes letting you plug all manner of things into an equally varied number of socket types.

Why do you scale them? You have selection input to filter them out

Is it possible to make it in 3d geometry ???

@Cranitz ... I didn't want to cross the wires :) Selection is mentioned in sentence bellow the screen ... I will change the screen :)

Version based on Curve ...

one curve in X axis > Curve to Points
on these points instance second curve in Y axis already with Curve to Points
you just control End Points of those curves


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How to rotate a mask in blender (Vfx not sculpting)
Within blender I was doing some vfx and got to the masking stage, It was going well till I wanted to rotate it, and I couldn't.
I intended to rotate it because certain parts the thing I'm masking it doesn't change it just rotates.
I pressed R on the mask and it didn't do anything.
I've already looked through google and other similar questions.
Before pressing R

After pressing R

Already tried that @susu

Can you share the file?

I cannot share the file. (Yes I know the images don't transfer over and how to lock tracks)

I can rotate a mask in a new file, but I have to admit if you will want to keyframe this rot it doesnt work as you probably  expact anyway, for more check here https://blender.stackexchange.com/questions/39344/how-to-rotate-mask-around-cursor

The issue was that the origin point was set to individual point not median point.
Which can be switched here at the top

I'm glad you found a solution. But please, next time don't crop the images so tight, it's hard to help without information.

Ok next time I'll add larger images with more information


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Distortion of the model
After selecting a group of points and moving them along the axis y, the corners of the object are distorted. I can't figure out what it's related to


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When I parent my mesh to the rigify rig, my mesh "disappears"
When I parent my mesh to the Rigify rig, my mesh "disappears". I can see it in edit mode very, very tiny. I bought the mesh, so I don't know how it was set up, but how do I fix it?

The parenting overwrites any former parenting, so, if the previous parent had some transform values different  than 000 000 111, it can cause "jumps" in loc, rot and scale.
To solve, select the model, press Alt P > Keep transform (Clear parent), then Ctrl A > Apply Rot and Scale, then parent to the Rigify rig.


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Unify the direction of a normal curve
I want to have the same direction of the normals. I can not do it manually because I have 900 segments and it impossible for me to selected one by one the segments that have the same direction before reversing! there is a way to do this quickly?

Blender File

Could prob do with a script, that runs thru the splines, looks at the direction of s[1].co - s[0].co selects if "wrong way" and run reverse direction op on selected, in which case a small test file would be handy.

Right, I tried to do with python, but I have enough experience in programming.
file attachments.

Here is a script that changes direction based on the difference  of angle between first and last spline points and the x_axis.  Run in edit mode.  You may need to change based on which direction to "unify" to.  As is it unifies all curves in the test file you posted to run right to left.  Change either the angle test or the x_axis direction to make all go left to right for instance.
import bpy
from bpy import context
from mathutils import Vector
from math import degrees, radians
curve_object = context.edit_object
x_axis = Vector((1, 0, 0))
# deselect all
bpy.ops.curve.select_all(action='DESELECT')
for s in curve_object.data.splines:
    v = (s.points[1].co - s.points[-1].co).xyz

    angle = v.angle(x_axis)
    print(degrees(angle))
    if angle > radians(90):
        for p in s.points:
            p.select = True

bpy.ops.curve.switch_direction()

perfect, it is strange that this is not natively in Blender. Thank you

authors: Андрей Федин

authors: Михаил Лаврентьев

authors: รัตน์ บ้านเมือง


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Can the GPU be used while video editing
I'm currently using Blender for video editing.
I have an AMD R7 and I have configured OpenCL in my user settings.
However, it doesn't seem to make rendering video any faster. Can the GPU be leveraged in this specific scenario or is it exclusively for 3D editing that the benefits can be seen?
Update #1
FWIW, exported in Blender using lossless method and will be encoding using VidCoder. Note, VidCoder uses all the cores on my system.

No theres no GPU assist for VSE and before you ask, no you can't have more cores either. You can make an OpenGL render (without audio IIRC) though.

@3pointedit thanks for the info... funny enough, my next question was to ask about the cores too! :)

Sorry I was in a hurry.

No there is no GPU assist for the VSE (sequence editor) and before you ask, no you can't have more cores either. You can make an OpenGL render (without audio IIRC) though. If you look at an OS task manager or resource monitor you will notice that there is very little stressing the CPU or memory. As it is not a core function of Blender it is not well optimized for system resources.

Hello from 2022. Same issue


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Curves in plain edges
I'm following a course in Blender. My assignment is to replicate a Bobcat S175:

I'm stuck at the part where I need to create the arms and back of the vehicle. This is how far I got:

For the arms I will need some sort of curves in the plains. I am wondering how to to this. To be more clear, I want to create these parts:

I hope someone has suggestions!

Edit: I tried making a mesh which looks like the back of the vehicle. I applied the sub surf modifier to this object and tried to play with the edge creases. However, I can't seem to get it better than this:


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cannot see object from 3ds import; does not appear to be scaling or translation issue
I am trying to import this .3ds terrain model into Blender 2.79b:
https://interstice.com/bquery.3ds
The import from File->Import->3D Studio seems to go without error. After importing, I see that 54K vertices, 44K faces, and 44K triangles are now present (from the top bar of the Blender window).
But I see nothing in the 3d view windows. I select the object in the object hierarchy and then press . on the number pad. Nothing. I zoom in. I zoom out. I pan left. I pan right. Nothing. I've tried all the suggestions from every "object not visible" question here and elsewhere but still cannot see the object.
I notice that some of the Translate and Scale parameters may be wacky for the object, so I reset those to seemingly sensical values. I still see nothing. Maybe the values change back on their own. I have another drink.
At some point in the past I was successful in importing this object into another viewer (probably Solidworks) and then exporting from there to a file and then importing that file into Blender, and then I could see the object. So it seems probable that Solidworks recognized something was wrong with the paramaters of the model and fixed it.
Now I'd like to figure out why I can't import this file directly into Blender and see it.
Thanks

"I've tried all the suggestions from every "object not visible" question here and elsewhere but still cannot see the object." I've tried applying the information in those questions, all of which I had already seen, but the screens depicted almost never agree exactly with what I have in my Blender version, presumably due to version differences.

Meshlab seems to be the best choice when it comes to convert simple 3ds files to obj, because it gives informative error messages when something's wrong with the file. If Meshlab has difficulties to convert your file into obj, then most of the importers are going to have problems with it.


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Is it possible to have separate animations, with independent timelines?
I've a scene with several objects that have (keyframe) animations attached to them. For clarity, think of a house with different doors and windows that can open and close independently of each other.
Right now, I've a single timeline that opens all the 'doors and windows' one by one. But I would like to be able to change when which animation plays when, independently of each other. I would like to, for example, open two doors at once, while all others stay closed.
Is this possible?

Yeah, open the timeline and the dope sheet:

On the bottom bar of the dope sheet windon change the "mode" from "Dope sheet" to "Action". Select a door, add an action and call it like "Door 1" and animate it from frame 0 the door opening.
Repeat until you have all doors and windows opening at the same time (only the beggining, you can have different ending times).
Then change the Dope Sheet window to the NLA Editor where you can see all actions:

Press the icon of the down arrows and you'll see that it creates a box, repeat for every object and then, choosing a box and pressing "g" you can move the box freely.

While I'm sure this answer is pointing to the right direction, the information is too sparse for me to transform my (existing) animations into action. Could you go into a little more detail?

If you already have the animation, go to the NLA Editor, and press the down arrow icon on the name of the object animated to tranform the animation into a block.


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Boolean modifier: Carve vs BMesh solver
What is the difference between the solver for the Boolean operator.
It is obvious that Carve and BMesh give different result, but I'm unclear on when I should use which one?
The documentation says: 'TODO' which isn't all too helpful.
Can anyone shed any light on their specifics and appropriate use-cases?

Carve booleans are used in Blender for a long time. This library has it's own limitations and cases when it will fail and produce incorrect results. It is also very slow.
Bmesh booleans is the new implementation aiming at being a faster solver (really shows on high-dense geometries). So far it also has limitations, but devs are working on it to resolve any bugs. You can trace the progress here:
BMesh booleans (track todo's)
Bmesh might handle some cases better than Carve and vice-versa. It depends on the geometry and those cases are hard to generalize. Bmesh should be faster than Carve. You should avoid non-manifold geometry for both.
In time Bmesh booleans might (hopefully will) fully replace Carve booleans.

Just a quick note that Blender has now removed the Carve boolean library. The last release containing Carve is 2.79. Further information can be found here: https://developer.blender.org/D3050


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Node editor, pick random Image Texture from set?
If have a bunch of (procedurally generated, converted to mesh) rocks. I have four  image textures (both color and bump).
Is it possible automatically pick a random image texture from the set of four image textures in the node editor, such that each object would randomly get one of the four image textures assigned?

This Randomizer Node Setup should work for what you want to make. If you want you could also switch up the mix shaders for mix color nodes to only randomize the images but I would suggest randomizing the shaders because 1. you only have to do this setup once and 2. you can individually control for example the strength of the bump map and the mixing factor of glossy and diffuse and so on...
Just to explain whats going on here: I have that Random number from the Object Info Node and multiply it with 4 to have a Number between 0 and 4. Then I split that range in half by checking of it is greater or less than 2. Then repeating the same procedure splitting that ranges in half but checking greater 1 and greater 3 if that makes sense.

I think I understand your setup; thanks to the "Just to explain whats going on here" part. Thanks!

And how do you this for three shader options?

@jspr you can use the same setup just multiply by 3 instead