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blender 2.69: Texture is not shown correctly
I have created two objects: plane and polygon. Then i joined them together to new mesh. For that new mesh i created a texture. Texture is shown in texture view, but not in cycles render completly. Only one object displays the texture but not the rest.
Picture is here:
Is that a bug? Perhaps i made something wrong.

Is it possible you could upload your .blend? It's hard to tell what might be going on from your screenshot.

Hi gandalf3, i cannot find a button to upload my blender file. I wanted to do exactly that. Where is the button? Drag and Drop is not working as well.

There isn't one on the site, but you can use pasteall.org

This could happen if both objects already have a material before being joined. Blender will copy all materials assigned in the source object to the destination object, all faces still assigned to the same material prior to joining. When you're creating a new texture, it's only assigned to one material, so it doesn't show up on faces still assigned to other materials when rendered.
The object's UV image could still be shown as you intended in the viewport, because it's assigned through image attribute of the object's UV map. It doesn't rely on Texture data at all. But what's rendered, do rely on it.
If this is the case, remove the unwanted material's slot, assign faces from the other object to the intended material, or assign the same texture to all materials in the object.

This was the solution, thank you very much. I realized now that my new object consists of two materials after joining. I deleted one material and now all is shown again.

Be sure to check these points:
Remove doubles.
Recalculate normals.
UV Unwrap mesh (both meshes).
I had some problems with scale, so try to apply scale (Ctrl + A)

I have done exactly this: remove doubles (no doubles were found), Recalculate normals, unwraped the finished endmodel. In 3Dview/textureView it is correctly displayed. But the render doesn't show it correct.


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Low quality mp4 renders
I have imported a 337 MB mp4 video file with no audio into Blender. In Blender, I am primarily just adding audio and then rendering back out to mp4. However, the rendered video quality is drastically lower, making much of the text in the video unreadable. The size of the output file is 65.7 MB.
In this image you can see my output settings:

Can anyone tell me what I am doing wrong? How can I get a higher quality render to mp4?

You should increase the bitrate. It determines the compression of the video data.
A starting point could be to set the bitrate as least as high as in the input file, and then add the Mp3 rate of 192kbs.
1920 x 1080 = 2,073,600 pixel count
24 frames per second
4 = High Motion

(2,073,600 x 24) x 4 x 0.07 = 13,934,592 bps / 1024 = 13,608 kbps bitrate

See sections 4 (Quality versus Streaming) and 5 (Starting Points), in this tutorial.

Also remember that Blender's encoder perfoms compression as a single pass and may not yeild the same result.

Following your formula I came up with a bitrate of 17,010 for an imported video of 1920x1080 at 30 fps. In Blender, I changed the following settings:
Bitrate: 17010
Minimum: 15000
Maximum: 17010
The output video has whopping 624 MB file size, which I would be fine with, but the blurry rendering remains unchanged as far as I can tell.

Also, I forgot to mention that the total bitrate of the source video that was imported into Blender is 8138 kps.

@Darren strange, if you're happy with input files quality with a higher bitrate the output quality shouldn't be diminished. You could lower the GOP (uncompressed keyframes) a bit and check the result. Otherwise I would choose a different format (at least for testing).

Ok, it looks like I am part of the way to solving the problem now. I overlooked the "Percentage scale for render resolution" setting. This was set to the default of 50%. After putting this to 100% the problem indicated in my initial post is now solved. However, now there is this strange pulsing that occurs approximately every second. During this "pulse", the video seems to move to a much lower quality and then quickly returns to a high quality.

I had the same problem.
The input video was of decent quality, but the output had an evident encoding problem resulting in bad quality.
The strip containing the video was starting before the frame 0. I can only presume that was causing the problem because after I hard cut the strip (instead of a soft cut) at a positive frame, the video was encoded just fine.
I'm a noob with Blender, so this is just my guess:
Perhaps the input video was decoded starting from frame 0, producing an error on all following frames.

source: Stack Exchange

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

sort: votes


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how can I make my particle affects not glow?
I am making a scene with a particle effect system in it, and I am wondering how I can take away the glow from the object. It is really bright, and it is not intended to look like that. Thanks

If you are using Emitter particles, you have to change the render type from Halo to something like Object, and use an object like a cube with a non Halo material on it.

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


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how can I change the size of particles?
I am fairly new to blender, and I am wondering how to change the size of the particles I am working with. They are way to big. Thanks

This can be changed in the particle settings under either Physics or Render (when using a display type that allows this) with the Size slider. You can also change the size of your particle objects by scaling the main object(s) you are using but it's best to control the size via the particle settings.
Additionally, you can randomize the size of your particles by using the Random Size slider.


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I am wondering how to make a storm trooper helmet in blender
I am fairly new to blender, and I am wondering how to make a storm trooper helmet. There are no tutorials out there, and I was just wondering if anyone knew how. Thanks

You could use an image of front and side view and set this as background image in the viewport, after that you would extrude edges along the contours, excellent exercise.

Any tutorial on head modelling that uses reference images can easily adapt to a helmet.

http://my.safaribooksonline.com/book/animation-and-3d/9780470102602/working-with-meshes/extrusion_modeling_and_box_modeling

Also, look for tutorials on hard surface objects. They will probably come in handy.


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Nodes are deactivated/inactive/greyed-out and cannot alter value
I have nodes but somehow they are greyed out and I am unable to change values. Did I press a hotkey accidentally? If so what was it?
An example is attached below;

Can you attach .Blend file?

@Georges, I'm sorry, I won't be able to. This is a commercial project and I would need to get a special permission from my client.

A workaround is to delete the lot and create a new material from scratch.

This issue could have been caused by linking in an object from another scene. When you link in an object, "ghost" materials are created - completely identical to the materials from the original file, but uneditable.
If this is the case, then simply append objects or materials themselves and you should be able to edit the nodes again.

Ah, my mistake indeed. I was LINKING, instead of APPENDING.

This is not the case for me. I am 100% sure I click Append, but the materials are still greyed out.

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


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Dimensions vs Scale without affecting animation
Before the issue:
For the past few weeks I've been doing a few animations on a Character with an Armature, with a pretty good certainty that I had the scale at 1.
Turns out, somehow in the middle of the process, (despite not being changed in size / scale since its creation) the Armature ended up with a similar scale to the character - which was set to about 0.10.
Probably happened automatically during the parenting and I didn't notice it?
I've been trying to come up with solutions to change their scales back to 1 without affecting the animations and I recently found out that

using ALT + S does exactly just that.

Current issue:
However...
I now have the issue of having - although properly scaled meshes and armature - really huge dimensions on both.
If I would export this into UE4 it would be ridiculously large.
On the same note, although having the same size and (now) scale, my Armature has nearly 13m in height while my mesh has only near 3?
Question 1: Does this difference in dimensions affect anything during the export?
Question 2: How can I change these dimensions without affecting the animations in any way?
Would really appreciate the help!
TL;DR: I've tried Applying Scale. Scale and Rotation too.
But I only found ALT + S to help with the Scale without affecting my animations and now I have huge dimensions on my mesh and my armature.
How do I change these without ruining the animations?

I actually just found this thread on a subreddit:
https://www.reddit.com/r/blenderhelp/comments/8eqx0g/armature_apply_scale_without_destroy_the/
--
Doesn't the scale of the armature need to be 1,1,1 for it to be exported correctly onto an engine?

I had tried this, but I was assuming the scale of the armature should be 1 as well, so I dismissed it. Was I wrong?

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


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How to level the bumps on the surface of the object?
I have created a human head, on that there are many bumps, which makes my mesh a mess, so what is easy way to level these bumps?

Can you show us the mesh in edit mode?

Did you try Smooth brush in Sculpt Mode? try uploading the file here, this might help: http://blend-exchange.giantcowfilms.com/

You might want to try the smooth and flatten brushes.

use proportional editing, very simple


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Why do my object collapses when moving armatures?
I have rigged the model, when moving or rotating the bone my model deforms.
Weight paint of my model,
When manipulate the bone,

And I am pretty sure that I have weight painted model correctly, I used point weighting for this. Please someone help!
Blender file here.. https://drive.google.com/file/d/0BwKqh0sK7cfeOFBOMEZFTVNJMmM/view?usp=sharing

Hard to see from the screen captures you provide here (no perspective to understand all). Can you share your blend file ? http://blend-exchange.giantcowfilms.com/

Actually, there is issues with the Weight Painting, the Armature and the mesh itself. I'll try to explain:
You did the weight painting for the left hand side of the character, and it seems to be fine, but what went wrong is mirroring it over correctly to the right hand side. When you rotate the hand joint there, some stray vertices in the legs move also, which should not happen. When I checked the vertex groups, the right hand joint was actually ok. It took me a while to find out that those vertices accidentally became members of one of the finger bones (PK.1.R). Since the finger bones change their location and orientation when you rotate the hand (they are a child of the hand bone), strange stuff happens on the legs. So here the weights need to be mirrored correctly over to the other side. Unfortunately, mirroring them using Blenders Mirror Vertex Weights tool failed for me when testing, I'm not sure why. Also check the center bones (spine bones for example), one of them is moving a finger, and all of them seem to affect parts of the face, which they surely shouldn't.
On the mesh I would question why the shirt has a thickness to it. Remember when you model that you also need to weight paint it correctly. From the inside, which is a pain! You can do yourself a favour and delete the inner faces, they never appear in a render anyways. Also in the helmet, it looks to me as if a vertex has been dissolved accidentally. That n-Gon in the back just shouldn't be there, you should have three quads instead.
And lastly, when using an Armature, unless you really intend to do so, make sure the Subsurf Modifier comes AFTER the armature in the stack. In your model, the Subsurf is on top of it, in Blender this means it is executed first, and the resulting Polygons will then be deformed by the armature. Not only does this make the calculation slower, and also the deformation gets a "chewing gum look" to it, it also has the catch that the amount of subdivisions can differ between viewport and render time. That means, the deformation will be calculated differently when you render than when you work on it, so you never see the final result correctly. If you swap the stack order, the hand deformation looks much better immediately.

Thanks, I have another doubt. When I move mutti.R, hand deforms. So please help me in that too.

the problem is that a few vertices have no weights at all, or to be clear, they are not assigned to any group. You can test this easily by moving rootia. Some hand vertices just don't move at all, which means the weighting isn't finished. If they would have weights on any bone of your rig, they would move with the root bone. If you check the weight colors on mutti.L, you'll see that far more vertices are included (you can also select the vertex group in the panel and use the select button to check) than on the other side with mutti.R. You'll have to work on the .R weights to fix this!


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import animation channels independently
I wonder if I can import keyframes (with a python script) only as x keyframe. It seems like I can only set the whole object location at a keyframe, but I want only set the x location, since y location may have different keyframes. Is there any solution for this?
I cant get it to work with object.insert_keyframe(data_path='location', frame = key.frame)
Otherwise I don't understand why the channels can be exported independently.
I already tried to import the specific x value by setting the current frames to the keyframe and use the objects frame location for y and z value.

Select the animated object, in the dopesheet select all keyframes you want to copy, Ctrl C to copy in the clipboard, select the new object, select the channel to be animated, set the cursor to the first frame where you want the copied animation to start, Ctrl V to paste the single animation channel.

To insert single keyframes select the object and type:
bpy.context.object.keyframe_insert('location', index=1)

Right click on the x-channel in the 3D Viewport's Right Side Property panel and select Insert Single Keyframe.

Hi, of course i meant import with a python script (i should have pointed that out more clearly). So is there sth like obj.keyframe_insert(data_path='location_x', frame=key.frame)


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How to make skirting boards in Blender geometry nodes?
I want to add skirting boards to all my walls and I thought geometry nodes would be the fastest way to do it. A flow like:

Duplicate Elements the wall object, so the original wall is untouched

Add 1.5cm to the x and y dimensions of the duplicate to make the skirting a little wider than the wall

Set the z dimension of the duplicate to 7cm to make it sit on the floor.

But I don't know how to do steps 2 and 3 at all. I can use transform geometry to scale objects by a percent, but not set absolute values. How to do this please?

Here's one approach to your problem:
I'm using a separate geometry node to isolate just the bottom edges of the wall. Then, using the curve-to-mesh node, I can use a profile shape to drive the shape of my skirting. I'm using a simple curve object to give it the cornice-bevel look.
You might want to change how the bottom edges are isolated for your setup. In my examle, my walls start at 0 on the z axis, so my compare float node works. If this doesn't work then flush out your question a bit more with pictures of your project etc. so we can best help answer

my skirting profile object (curve)

Thanks. I don't want to make another object for the skirting board in my main project. I'd rather just use a 1.5x1.5x7 cm cube that flows along bottom edge, made in the geometry nodes. Is that possible?

@Richard Yes, you can make a quadrilateral curve primitive in geometry nodes and use that as the profile curve instead. Or you can use a grid mesh primitive, define the size, and then do mesh to curve and use that as your profile curve

I'm struggling with the selection part - even selecting the whole wall just seems to run three razor blades around the edges. I've added a Blend file in my question trying to implement what you said and would appreciate it if you had any time to look. The object with nodes is walls - _wallSkirting.

@Richard I believe you need to put your geo nodes modifier last in the stack, after the boolean modifiers. And your geometry nodes object's origin isn't on the ground, thus causing your edge selection to be off. reset transforms and it should work

Thanks, when I applied location and moved the doorway modifiers up then a skirting appears - but only in the x-axis, not in the y-axis. In the y-axis it's still just a flat wall.


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Why is my Blender render blank?
I've tried everything I understood from this question, Render result is completely blank, but pressing F12 still gives me a blank render window.
File is here:
Update: I just noticed there is what looks like a little error message briefly in the status bar: "Build without OpenImageDenoiser"

Hello and welcome. While files, images, and external videos or links may be helpful additions they should not be the only way to obtain information about your issue. Don't make understanding your question rely on downloading a file, watching a video or visiting an external site. Use the builtin tools to upload images or gifs, along with thoroughly explaining the problem in written form so it can be indexed and searched for thus helping future visitors with similar issues.

Scene renders just fine for me, so i guess its not a scene setting, but more likely a technical problem on your side. Do other blend files render? Does it render if you change something under File > Preferences... > Cycles Render Devices?

Your file renders perfectly fine on my PC. Maybe it's an issue with your graphics card and/or the necessary drivers?

Thank you both. That's so weird. I don't know what else to check. I'll try update all my drivers and install the CUDA thing I guess.

Ok, the problem is the Blender version in APT on Linux is old and broken. Installing Blender with Snap so it's as recent as possible fixed it.


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How to make Blender render in real-time, as fast a computer game?
I understand from this answer (https://gamedev.stackexchange.com/questions/136757/how-do-modern-game-engines-achieve-real-time-rendering-vs-blenders-slow-rende#answer-136776) that

computer games (and libraries like three.js and babylon.js) simply project objects onto the camera, and can thus render instantly
whereas Blender does raytracing, which takes minutes per frame.

Is there any setting I can change to make Blender use the projection mode of rendering rather than raytracing?  I've already done all the rendering performance tricks and I'm still orders of magnitude away from real time.
The answer referenced above says Blender Internal renderer is much faster than Cycles, but Internal is being removed from Blender 2.8 onwards, so that's not a solution.

If there is no Blender solution, then would using Blender to make models and Unity to make animations be be the best plan?  I haven't used Unity but I assume it can do the speedy rendering thing.

Have you looked into 2.8ths eevee engine? Or how about the blender game engine?

Do you want to make a game or a movie?

Thanks @kanukit. Looks like 2.8 solves my problem with real time rendering. I'll download the alpha and take a look.

Use the Blender 2.80 Beta Version to get a new render engine called Eevee. The engine is lighter in performance consumption and can do real  time rendering even more realistically than the traditional Blender Render engine. Note: Before you open the old Blender file in 2.80 Beta, then keep a backup copy. Because once you open or create a project in Blender 2.80 Beta then you can't open it again in older versions. The physics engine is not yet completed. So, don't use the physics engine in Blender 2.80 Beta. If there is a bug or a problem in a feature of Blender 2.80 Beta,  then download the next day's version to get a better working version of Blender 2.80 Beta.


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Trimming the edge of a picture (not resizing)
this might be something I can't do in blender. I know what to do in photoshop etc but i was hoping there was a quick way around having to do that.
I have an imported image i want to use on the side of a box , its just s bit big and i want to trim the edges so it fits nice.
in the pic the left image is the box with knobs etc that i want the image cropped in size to fit. The right image is just as a referene to what it looks like on its own.
I want to crop the black edge around it.
Possible?
Thanks.

do you mean scale the picture so that now the edge is white? or paint in white? In the first case, scale the UV of the object in the UV Editor. In the second case you can paint the image in the Image Editor (or even in the 3D view in Texture Paint mode)

Hey Moonboots, see how the left one has a box under it? I want to trim the excess black around the outside of the picture so it fits flush with the box underneath. The edge of the pic is the interior white box. The black around the edge is just background and I want to get rid of it.
THANKS.


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Gltf animation not playing/exporting properly
In a project I'm working on, to create a visual in a gltf that the gameboy screen is moving, I ran a script that tells each and every panel to move back and let the next move forward, thus making it seem as if the screen is doing something. However, When I export all goes well except for the last two screens. the seem to be out of place way to the right until its their turn to show. I tried to delete the last two screens, But all it did was recreate the problem with the screens left. There is 17 screens in total And a BG screen that should not move. Any Idea how this could be fixed?

This is he script I used:
import bpy

# Number of frames to show each image
duration = 21

# X position of plane when it's in the front
x_front = 0.644278

# X position of the plane when it's in the back
x_back = -0.183634

# Fix inconsistent name for 1scr
if "1scr" in bpy.data.objects:
    bpy.data.objects["1scr"].name = "1src"

# Remove 18src, it's a copy of 1src
if "18src" in bpy.data.objects:
    bpy.data.objects.remove(bpy.data.objects["18src"])

last_n = 17
for n in range(1, last_n + 1):
    name = "%dsrc" % n
    ob = bpy.data.objects[name]
    action_name = ob.name + "Action"

    # Clear out existing animations
    ob.animation_data_clear()
    if action_name in bpy.data.actions:
        bpy.data.actions.remove(bpy.data.actions[action_name])

    action = bpy.data.actions.new(action_name)
    action.id_root = 'OBJECT'
    fc = action.fcurves.new(
        data_path="location",
        index=0,
        action_group="Location",
    )

    pts = []
    f = (n-1)*duration
    if n != 1: pts += [0, x_back]
    pts += [f, x_front]
    if n != last_n: pts += [f + duration, x_back]
    elif duration > 0: pts += [f + duration - 1, x_front]

    fc.keyframe_points.add(len(pts) // 2)
    fc.keyframe_points.foreach_set("co", pts)
    for pt in fc.keyframe_points: pt.interpolation = 'CONSTANT'

    # Push to NLA track
    ob.animation_data_create()
    track = ob.animation_data.nla_tracks.new(prev=None)
    track.name = "nouns"
    track.strips.new(action.name, 0, action)
    track.mute = True
    track.is_solo = False

Here is a link to the blender file: https://www.mediafire.com/file/ae4yob23aw2h0f0/NOUNS+GB+BLENDER.zip/file

lol I wrote that script specifically for your last file, it probably won't work on any other file.

Its seems to work fine until that last bit. I changed it up to specify where the planes should be exactly as this one has the planes in a new location.

Do you think you could help me out please? I realized the link was to a file that was not updated. I went ahead and updated the link to the correct one.

The reason it doesn't work is it moves the panels on the X axis, which in this model is left-right. You need to move on the Y axis this time. You can change the index=0, to index=1, to make it do the Y axis, but I don't know if it will work. Like I said it was just an off-one script. (Also remember to pack images into your .blend before uploading.)


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Object getting rotated with the Array + Curve modifier
I'm trying to make an object follow a simple curve, however I'm having issues with the object rotating once the curve modifier is applied on it, and I can't figure out how to have it rotate the way I want it to go.
I have the following curve, and a simple rectangle object that I want to duplicate along the path of the curve. Think of road markings following a road.

I've set the origin of the curve and rectangle to their respective geometries. I then set the 3D cursor at the curve's origin, and then Shift + S > Selection to Cursor on the rectangle. I've also applied all transformations as well.
When I apply the Curve modifier to the rectangle, it rotates the rectangle, and no matter what I do it won't rotate in the way I want it to. I've tried:

Applying different rotations on different axis
Applying the scaling on different axis
Rotating the curve in a bunch of ways

But it all results in the exact same situation where the object isn't oriented the proper direction I'd like it to be.

If it makes a difference, the curve was made via Duplicating another Object's Loop Cut and converting it into a curve, then removing the 'bottom' vertices from that curve.
How can I get the rectangle oriented correctly along the curve?
EDIT: Here's the blendfile https://pasteall.org/blend/8f47a59305a24b01aaeaa348d8611e57

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

@moonboots Just edited my OP with the link

As you've applied the curve scale, it has increased its vertices radius, bring it back to 1:

Thank you so much! After resetting the radius back to 1, I could rotate the rectangle without it deforming completely

Kindly check this, if this can help. https://pasteall.org/blend/480c8368348c44a48301f5d4bcd594a8
cheers


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modal function of a modal operator is never called
I want to receive real time data into blender based on which I would control some animation. To receive the real time data I am using a datagram socket with a modal operator. But for some reason the modal function of the operator is never getting called
Here is the code for my operator
import bpy
import socket
import os
import sys

absolutePath = "/Users/pulkitjuneja/Documents/projects/EVA/scripts"
sys.path.append(absolutePath)

from animationController import main

class socketModal(bpy.types.Operator):
    bl_idname = "object.modal_operator"
    bl_label = "Lip synch Operator"

    def __init__(self):
        print("Listen Start")
        os.chdir(absolutePath)
        self.port = 1301

    def __del__(self):
        print("Listen End")

    def execute(self, context):
        print("execute")
        return {'RUNNING_MODAL'}

    def invoke(self, context, event):
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.socket.setblocking(0)
        self.socket.bind(("127.0.0.1", self.port))
        self.execute(context)
        print('socket listening on port', self.port)
        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

    def modal(self, context, event):
        data = None
        try:
            data = self.socket.recv(1024 * 1024)
         except socket.error:
            print('no data')
        print(data)
        print("here")
        if event.type == 'BACK_SLASH':
            self.socket.close()
            return {'FINISHED'}
        return {'RUNNING_MODAL'}

bpy.utils.register_class(socketModal)
bpy.ops.object.modal_operator('INVOKE_DEFAULT')

I am running this script inside blender to register and run the operator but only the invoke function seems to be called. Is there anything I am doing wrong ?

The invoke function have to set the operator as modal adding a handler for it, with something like 'context.window_manager.modal_handler_add(self)' (see the corresponding code template in the UI)

Thanks a lot ,That fixes the issue. But now the operator freezes blender. why is that happening ?

Where have you add the handler exactly? and what is traced on the console?

i am just running this script through the python text editor in blender and then starting the operator using space bar in blender. The modal function runs repeatedly printing "here" but the blender interface freezes

Catch exception if there is no data. Something like "try: xxx.recv(size) etc" then "except: no data to receive". A code template here http://whitepythons.blogspot.fr/2014/05/non-blocking-mode-and-timeouts-sockets.html

did that already, updated the code in the question. After doing that the code runs without any errors ,but freezes blender. Could that be because the modal operator acts like an infinite loop ?

Could you update the complete code? your update does not include the handler setting.

okay added the updated code now

This is a bit late, but, at present, the modal operator will be invoked at every(!) blender event. This is perhaps not what you want, and could be the source of your problems. A better idea for such operators is to be restricted to particular events. For example, you could start a timer that triggers every 1 second:
bpy.context.window_manager.event_timer_add(1, bpy.context.window)

And, in your modal function, have:
def modal(self, context, event):
    if event.type == 'TIMER':
        # do something
    return {'RUNNING_MODAL'}


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Invisible wall problem( Link to blend file in comments)
thanks for your time! I know this is most likely a noob problem but it is driving me NUTS , I can't seem to find an answer anywhere. When i create a 3d house model, unwrap it, then export it to unreal as an fbx, most of the walls become invisible...I read somewhere about flipping the normals,i tried that but it still aint working. if ANYONE has a solution i would REALLY appreciate it :) thanks

could you upload the blend file

hey dude, thanks for the reply, i dont actually have it anymore :S if it helps, it happens EVERY time i try and build a house. I built a quick house this morning(windows, doors etc) and the same happened when i imported in into unreal engine.

You should repeat what you've done and replicate the problem and save and upload the blend file. This way someone can help you.

ahh ok fair enough, will do, ill get a quick simple house done now. when i do it, how do i go about uploading it on here? sorry, im new to this site :P

ok i have a quick model house, it cud be down to the uv unwrapping as im new to blender.

@Nate Just a tip, that HTML string you just commented is meant to be edited into your original post by choosing edit under your name, and paste it in somewhere. Here's the official help page for Blend-Exchange


text:
How can I loop two different animations with one playing right after the other?
I am trying to loop two different animations in my game, one right after the other. In this case I am trying to have SlimeJump1 play, then SlimeJump2 play, then have them continuously play in this order. I have already tried delay sensors, and they won't work. How would I do this? The download link for the file is here. Thank you!!!

Sorry for being such a noob, I'm sure there's a simple way to do this. :P

Feel free to experiment with the file as much as you want.

You could use the State feature to put the character into a new state after the first jump, which signals the second jump to act. I'm a noob too so that's about all I can offer at this point.

Ok, so to do this, you have to have two states. On the first one, you have an always sensor playing the first animation. Then you have a delay sensor that is set for 3 * length of animation - 50 hooked up to a state actuator that changes the state. The second state is the same, but you play the second animation.

I agree on the state machine. This allows to describe the sequence of actions. But using delay sensors makes you setup animation information (when the action ends) twice. Better use action actuators. See: https://blender.stackexchange.com/questions/50732/how-to-start-second-action-after-check-that-first-one-is-done-in-bge/51008#51008


text:
How to bake Mantaflow simulation in version 2.83
I tried development versions before, and there I could use Object > Quick Effects > Quick Liquid and there'd be bake data / bake mesh buttons in the Physics Properties.
Now, it seems like the bake happens in the background, and I don't know how to re-bake the simulation after adding e.g. an effector.

You need to switch to Settings > Cache > Type > Modular:


text:
Update function for NodeSocket?
How do I set a callback for socket input change (value or link change) when having a custom node?
I have a socket defined like:
self.node_tree.inputs.new("NodeSocketFloat", "Start")

Is there a way to call an update function such as when working with a Property, for example:
bpy.props.FloatProperty(name="Value", description="Trololo..",default=0.0, update=update_effect)

Now it seems like the whole compositor gets refreshed when changing the socket value but I need to actually compute something not related to the linked group nodes to the changed socket just like when the property gets changed and calls the update_effect.
Thanks.
EDIT:
I have tried defining socket_value_update function which doesn't seem to work at all. update function does what I need but only when a link to the socket is removed/added, not when the value changes.
EDIT2: I've opened this issue here.


text:
Custom compositor node - connecting input to output
I am trying to make this simple node group that would simply connect the input to the output so it would simply repeat an image like below.

What is the problem with my code? It's like nothing is coming out from the output.
import bpy

class Repeat (bpy.types.NodeCustomGroup):

    bl_name='Repeat'
    bl_label='Repeat'

    def init(self, context):
        self.node_tree=bpy.data.node_groups.new(self.bl_name, 'CompositorNodeTree')
        if hasattr(self.node_tree, 'is_hidden'):
            self.node_tree.is_hidden=True

        self.node_tree.inputs.new("NodeSocketColor", "Image")
        self.node_tree.outputs.new("NodeSocketColor", "Image")
        self.node_tree.nodes.new('NodeGroupInput')
        self.node_tree.nodes.new('NodeGroupOutput')

        #trying to connect input to output here, possible problem?
        self.node_tree.links.new(self.node_tree.nodes['Group Input'].outputs[0],self.node_tree.nodes['Group Output'].inputs[0])

    def free(self):
        bpy.data.node_groups.remove(self.node_tree, do_unlink=True)

from nodeitems_utils import NodeItem, register_node_categories, unregister_node_categories
from nodeitems_builtins import CompositorNodeCategory

def register():
    bpy.utils.register_class(Repeat)
    newcatlist = [CompositorNodeCategory("CP_GENERATE", "Testing", items=[NodeItem("Repeat"),]),]
    register_node_categories("GENERATE_NODES", newcatlist)

def unregister():
    unregister_node_categories("GENERATE_NODES")
    bpy.utils.unregister_class(Repeat)

try :
    unregister()
except:
    pass
register()

The node stuff you are doing in register is from custom pynodes, use them only in their own custom node trees as they don't mix well with standard nodes. You want to create an operator that creates standard nodes in a group. The code in your init is close, but old - as in pre2.67, see this answer.

@sambler Ah thanks for the link, I didn't know it's obsolete.

@sambler OK seems like I managed to create a working node_tree but for some reason it's not working in the custom node but the same tree is working when assigned to a node group node. I however wanted to make the node customizable looking like standard nodes, not this ugly group :D. Any way how to do it?

As I mentioned, custom nodes do not interact with existing nodes, as one of the blender devs answered PyNodes do not make it possible to extend Blender Internal, Cycles or the compositor with new nodes. At this stage a group node is the option you have, you just have to accept having the node group list in your node until a developer offers a better solution.

@sambler I see, kinda weird but can't be helped I guess. Thank you for your help! :-)

@Hitokage I've checked the source code, and as I suspected the NodeCustomGroup is discard when the complete node tree is evaluated... For now, that class only works directly with Cycles nodetrees.

@Secrop I see, can't be helped. Thanks anyway.

Just to update the information in this thread: 2.80 now gives the hability to create custom nodegroups for Compositor! One just needs to derive #CompositorNodeCustomGroup#, and work the same as using the former #NodeCustomGroup#.

Amazing! Thank you so much @Secrop for this update and remembering this post!!!


text:
Is it possible to make this in one piece?
I stuck over here. How do I make the middle part to a Cylinder and keep this as one piece? Thanks a lot!

Hello :). You can turn the rectangle into a cylinder using the To Sphere operation. Just subdivide the top/bottom edge loop.

The rest of the geometry turns into a mess. lol


text:
How to create this type of icing and bite mark?
I made the donut already with Array and Simple Deform modifier. The file is 2.4M, somehow it can not be uploaded to blender-exchange.
Thanks for your time!

for uploads you can use https://blend-exchange.giantcowfilms.com/ - follow the instructions there and edit your question afterwards with the link that is provided by that partner site

You could cut out the bites in the mesh, using the boolean modifier, and create a procedural dough shader.


text:
Box lid does not open right in animation
https://www.reddit.com/r/BlenderDoughnuts/comments/ehcs83/y_is_it_doing_this_lol_help_please/?utm_source=share&utm_medium=web2x
The lid of the box can be positioned, but once the keyframe created, the rotation has completely changed to different things. Please see the video above.

No Option is available somehow.

The issue is that you want it to rotate on one axis only. However, the local axis for that object is not aligned in that direction, so Blender is trying to rotate it on both the x and y-axes to get it to that new position.
Here's a plane rotating the way you want it to. I've shown the local axis of the object to make it clearer how the plane is only rotating on its local Y-axis.

Now I've applied the transformations of the plane and applied keyframes in the same object positions. You can see how the local axes no longer align with the direction of rotation.

Uh oh! That is not looking good. So how do we fix it?
The first thing you want to do is to clear the object's animation keyframes.
Next, activate the Select tool while in Object mode. You're then going to need to go to the Active Tool and Workspace Settings tab. Under Options > Transform > Affect only, select Origins.

Now, select the box lid and rotate it with R. However, now you will only be rotating the object's origin, not the position of the object itself. Align one of the object's axis so it is normal to the plane of rotation (something that looks like the Y-axis in the first gif, this axis should stay in one place while the object is rotating).
After that, reposition your object and set the keyframes for your animation again.
PS: Nice job with the donut tutorial! I like what you've done with it.

Thank you. I am working on it now. Hopefully, get it done on time.
PS: Thanks! :D

Hi stphnl329, There is no OPTIONS there. I posted the screenshot on the original post.

You need to update Blender from 2.80 to 2.81

This new feature is amazing, lifesaver! Thanks again!


text:
Assigned Materials Show Up in Render Preview but Not Final Render
Blender Version 2.77
I’ve been working on a render of a lightbulb recently and I have been having troubles with material slots.
I have the materials shows below assigned to certain vertex groups that I selected and then hit the assign button in edit mode to assign the material. Note: I have no textures, only materials.

So the main problem though is the materials that I assigned not showing up in final render. It shows the assigned materials in render preview and the material view but never the final render.
Here is render preview:

Here is the final render:

As shown above the render preview shows the assigned materials while the final render shows only the first material slot. Also remember that there is no textures and I have made sure that the correct faces are assigned as well as all nodes are connected.
Object screen:

I can provide more information if necessary.

Materials aren't assigned to vertex groups, they are applied by face. https://blender.stackexchange.com/questions/516/add-different-materials-to-different-parts-of-a-mesh

They were only using the vertex groups as a middlemanr to select the vertices; after they were selected, they were assigned to the material in question.

Okay, I've learned something very important. Not only make sure the mesh is showing or not showing in final render or the viewport, but also check the modifiers.
I found that the remesh modifier was showing in render mode but not the viewport and this was causing a crap ton of problems.
So the lesson is. Make sure to check your modifiers. Also remesh sucks.

I'd just like to point out that remesh can be very useful! ... But only in certain cases. (:

It look more that your material isn't doing what you want it to do, as opposed to being improperly assigned. Look on your render properties tab, and see how you're telling blender to handle transparency. You might need one or more of the following:
--More transmission bounces. This lets the ray bounce around a few more times (in this case, through a few more surfaces) before giving a result back to the render engine. If it's set pretty low, you can end up with fairly opaque materials, because you have to bounce it through its surfaces (front AND back) and return through the same way to the camera. I'd recommend at least four more bounces than your minimum bounce number, but twice as many as your highest bounce is ideal. If you're trying to make less-noisy glass (my heart goes out to you friend) try increasing clamp indirect, instead, or play with the Light Path node in your material.
--More render samples. This is in the same vein as above, but it's important to note the maximum value should be your highest bounce number, and your minimum value should be your lowest bounce number. If your preview bounces are higher, this could be exactly your problem. Preview is what you see in render view in the viewport and Final is what you see when you hit the Render button. They don't have any bearing on each other, and can be totally different. Your Final value should be at least as high as your highest bounce for best results, but you actually can get away with less in most cases; you'll have to play around with it to see what works for your scene.
--Enable or adjust transparency. Sometimes, for some reason, this isn't checked. I assume for performance reasons, as it can be computationally expensive in many cases. If you can't find it, look for a collapsed menu that says 'shading'. You'll want Ratrace selected, and your alpha slider anything greater than zero. I'm not sure if this specifically was only a Blender Internal option. You might not have all of those settings, but transparency should still have it's own section or subsection. The main point is to make sure you're not using the world material for your transparency mixing.
Alternate things to look into:
--Check your material settings. Make sure your material is doing what you want it to do. It could be that it's a little too reflective, and all the light is bouncing off instead of passing through. You can adjust this by mixing in a Transparent node, with Layer Weight as a mix factor (you'll want the transparency plugged into the top slot, and I find while Fresnel gives more accurate results, Facing is more visually appealing).
--Adjust your lighting. I'd say easily eight times out of ten, if your render isn't looking right, it's because your lighting is off. From the look of your render, the light is shining directly onto the lightbulb. Because of the way Blender calculates Fresnel, which is automatically included in the Glass node, anywhere light shines directly onto something is going to be less transparent. Simply changing the position so it's on a different angle than the camera could very well improve your results. This includes the light coming from the filament. The filament should be brighter than any other lightsource, if you want it to be on.
--Thicken your glass. Instead of making it a single solid shape, make it a shell. That is, with visible thickness. This will make the glass the thin shell you're trying to tell Blender to render, instead of the thick solid mass it thinks you want. I don't remember when the thickness modifier showed up, but this is perfect for this task, and it'll save you a few vertices. If you don't have the thickness modifier, or just don't want to use it, copy your glass vertices, shrink them slightly (ALT + S is best for this kind of object) until it's the thickness you want, then flip the normals via the tool panel. There should be an option on the tool shelf, but if there's not, searching 'flip normals' will bring it right up for you.
--Adjust your environment. Give your lights more places to bounce off. As it stands, you have the lightbulb and your plane. This isn't enough for the resutls you want to achieve. Make a cube or sphere around your scene just big enough for your camera, lighting, and objects. Make sure the normals are pointed inwards. If you want it invisible, don't make it transparent, the rays will just go right on through. Either use a Holdout node, which will make it like a hole to see the world background, or mix in a Transparent node with your original texture and plug Camera Ray (on the Light Path input node) into the mix factor. This will make it invisible to the direct camera rays, but allow light to bounce off for things like reflections and indirect lighting. Your nontransparent material for this can be anything opaque, but rougher object will bounce softer light than smooth objects, and brighter colors will bounce more light than darker ones.
I hope this helps! Happy Blending!

I've tried all of what you said above but it still is not assigning the materials in the final render. In this image I moved the filament material up on the material list and it changed the whole mesh.

So did you solve it? I wasn't entirely sure by your answer.

Yes, it was just a modifier not being shown in the final render.


text:
How can I make a rounded indentation on a cylinder? (Cosmetic Plastic Bottle Lid)
I'm trying to do a cosmetic bottle in blender but i don't how to do this thing in the image. How to do this round edge on the cap. Can anyone help me?

Why this question is downvoted so much? It's pretty hard topology concern...

I tried to find a tutorial and tried to do it myself but i can't. I guess it's a good question and will help other people.

Thanks you cegaton for the edit. Never heard of the word indentation before.

Tomorrow I'll make an answer with nice quad proper topology.

Apart from Boolean Inset and then scaling inwards along normals (Alt+S) can do that.

Though you may do it using Boolean Modifier (or BoolTool add on) the good solution here may be using an Inset tool since it'll allow you to make a clean topology mesh.

Add a cylinder with 16 subdivisions. Add edge loops Ctrl+R to define the indentation position. Select the faces representing the indentation and press I,B (to enable Boundary mode). Repeat it twice (to create the extra edge loops for subsurf creasing). Extrude it inwards (E), then inset again as before.

Add the additional edge loops to the indent, then form its shape transforming some vertices. Finally fill the top part of the cylinder with mesh (example topology pictured in the first .jpeg).

Damn, I wish I could upvote twice. Years using Blender now and I didn't know about that Boundary Mode for the Inset operator, that second GIF caught my eye. Life saver, insanely useful when working near the symmetry axis with the Mirror modifier. Thanks for this!

@Duarte Farrajota Ramos Thanks for kind words. You have no idea how often I discover obvious/basic blender tools after many years :).

To answer to Kosmani's question here, which is about a slightly different lid:

You can begin with a 32 vertex cylinder and 16/8 vertex sphere that you'll use as a boolean object:

Apply the Boolean, add some horizontal edges with the knife tool:

Rearrange the topology a bit, give your object a Solidify modifier:

Apply the Solidify, bevel the edges in order to sharpen when you'll give your object a Subdivision Surface modifier:


text:
Strange transparency/artifacts when baking normals from a high-poly mesh
After adding a bunch of details (using KITOPS inserts, mostly) to a high-poly mesh, I've been attempting to bake the details of the mesh to a normal map for a lower-poly version. For some reference, here's a screenshot of the high-poly mesh:

And here's a screenshot of the low-poly mesh:

This is maybe my fourth or fifth time ever baking textures for 3D models, so excuse me if I use any confusing terms or anything like that, but I've been following some video tutorials and I believe that everything should work as I expect it to. When I actually try to bake the normalmap for the low poly mesh, though, I get some very weird results, where some elements (mostly, the KIT OPS assets cutting in to the high-poly) are not correctly present in the baked texture, and are partly (or entirely) transparent, depending on my "Extrusion" settings under the Scene panel > Bake > Selected to Active menu. Here's what the baked texture looks like with Extrusion set to 0.4m, which I understand to be a pretty reasonable extrusion setting:

And here's what the output looks like with Extrusion set to 0m:

(Note that the transparent elements in the first texture, like the hexagonal "bolt" and the rectangular boolean cutting into the mesh next to that, are partially visible and display that artifacting I'm referring to in the second texture.)
I've tried fine-tuning the Extrusion setting to find a sweet-spot where the bool elements will be visible but not artifacted, but I wasn't able to fix the problem that way. Is this an issue with my meshes? Or is something going on with the renderer?
For the record, I've restarted my Blender, and my computer, multiple times since this issue first began, and nothing has changed.
(My renderer is Cycles (using CPU), and I'm using Blender version 2.93.1, and my OS is MacOS 10.15.7)
Thanks for any help y'all can provide!

And if you increase Extrusion value? There isn't reasonable Extrusion in general, only for a particular case as it solely depends on scale of the model in the scene. If you aren't lucky in baking with it set to higher value maybe custom cage will be required

@MrZak, increasing the extrusion value results in outputs similar to the 0.4m Extrusion setting output, where the transparent details remain transparent.

Make sure normals are pointing correctly (outside) so that object is blue in Face Orientation overlay. Other than that, construct a cage to define custom extrusion value for baking (see online examples for cage, normally duplicate lowpoly)

@MrZak Gotcha. The transparent areas in the bake occur where I'm using cutters from KIT OPS to boolean cut into the high-poly mesh, so perhaps something about those boolean operations is causing problems with the normals of the faces in the result of the cut.


text:
Having trouble incorporating adding materials to current python code
I previously had an issue that was solved by @scurest. He rewrote my code to make it much faster. I had another version of the code that applied different materials to each cylinder according to a value in an excel file. I have not figured out a way to incorporate this correctly. I get errors about my floats even though they worked previously. I also received this error:
TypeError: mathutils.Matrix.Diagonal(vector), invalid vector arg: sequence index 1 expected a number, found 'str' type,

Everytime I adjust something I get a new error. Please see the code below.
import math
import bpy
from mathutils import Matrix
import csv
#opens csv file to be read and stores it as the variable f
with open ('C:/Users/MacLab/Desktop/Modeling/Neuron 43 EM Post Analysis wo Labels.csv') as f:
    #sorts through the data in f and makes a list of values from them
    readout=list(csv.reader(f))
    #print(readout)

# Create a cylinder to use as a "template"
bpy.ops.mesh.primitive_cylinder_add(
    vertices=32,
    radius=1,
    depth=1,
    enter_editmode=False,
)
cyl = bpy.context.object.data
cyl.name = 'tmp'
bpy.data.objects.remove(bpy.context.object, do_unlink=True)

for ai, a in enumerate(readout):
    start_t = time.time()

    mesh = cyl.copy()
    mesh.name = a[0]
    radius = (a[3])
    depth = float(a[5])
    mesh.transform(Matrix.Diagonal([radius, radius, depth, 1]))

    #assign material to object
    #if the value in the coloumn referred is equal to 1, then get the dendrite material and add it to the active object
    if (a[18]) == 1:
        #get material
        mat = bpy.data.materials.get("Dendrite")
        #print('DR')
    #else if the value in the coloumn referred is equal to 2, then get the Terminal material and add it to the active object
    if (a[18]) == 3:
        #get material
        mat = bpy.data.materials.get("Both")
        #print('DR')
    if (a[18]) == 2:
        #get material
        mat = bpy.data.materials.get("Terminal")
        #print('PS')
    #in any other cases, get the Silhoutte material and add it to the active object
    else:
        #get material
        mat = bpy.data.materials.get("Silhouette")
        #print('NONE')

    # Copy the template cylinder and scale it to the right radius/depth.

    mesh.materials.append(mat)

    ob = bpy.data.objects.new(a[0], mesh)
    ob.location = (0, float(a[6]), 45000)
    ob.rotation_euler[0] = -math.pi / 2

    bpy.context.collection.objects.link(ob)

    print("%d : took %.4f" % (ai, time.time() - start_t))

# Done with the template cylinder so remove it
bpy.data.meshes.remove(cyl)

I was able to use the code below and added zeros in the csv where the code was expecting values. I readded some floats and also changed two of my if statements to elif.
    import time
    import math
    import bpy
    from mathutils import Matrix
    import csv
    #opens csv file to be read and stores it as the variable f
    with open ('C:/Users/MacLab/Desktop/Modeling/Neuron 114 EM Post Analysis wo Labels.csv') as f:
        #sorts through the data in f and makes a list of values from them
        readout=list(csv.reader(f))
        #print(readout)

    # Create a cylinder to use as a "template"
    bpy.ops.mesh.primitive_cylinder_add(
        vertices=32,
        radius=1,
        depth=1,
        enter_editmode=False,
    )
    cyl = bpy.context.object.data
    cyl.name = 'tmp'
    bpy.data.objects.remove(bpy.context.object, do_unlink=True)

    for ai, a in enumerate(readout):
        start_t = time.time()

        mesh = cyl.copy()
        mesh.name = a[0]
        radius = float(a[3])
        depth = float(a[5])
        mesh.transform(Matrix.Diagonal([radius, radius, depth, 1]))

        #assign material to object
        #if the value in the coloumn referred is equal to 1, then get the dendrite material and add it to the active object
        if float(a[21]) == 1:
            #get material
            mat = bpy.data.materials.get("Dendrite")
            print('DR')
        elif float(a[21]) == 3:
            #get material
            mat = bpy.data.materials.get("Both")
            print('BOTH')
        elif float(a[21]) == 2:
            #get material
            mat = bpy.data.materials.get("Terminal")
            print('PS')
            #in any other cases, get the Silhoutte material and add it to the active object
        else:
            #get material
            mat = bpy.data.materials.get("Silhouette")
            print('NONE')

        # Copy the template cylinder and scale it to the right radius/depth.

        mesh.materials.append(mat)

        ob = bpy.data.objects.new(a[0], mesh)
        ob.location = (0, float(a[6]), 25000)
        ob.rotation_euler[0] = -math.pi / 2

        bpy.context.collection.objects.link(ob)

        print("%d : took %.4f" % (ai, time.time() - start_t))

    # Done with the template cylinder so remove it
    bpy.data.meshes.remove(cyl)

```

radius = float(a[3])

and will run into similar hassles with a[10]  every item from csv will be a string unless converted eg material_index = int(a[10] ... if material_index == 1  or if a[10] == "1" or they'll never be true. ... it will twig, sooner or later,  to where the error messages become  pretty self explanatory.

in reference to radius = float(a[3])... the system is giving me this error ValueError: could not convert string to float: '' ... it doesn't work when I remove float and has worked in the past with the float. I double checked that I am calling the correct column in the csv as well.

I am not exactly sure what you are saying in the other comment :/ would you be able to rephrase? i appreciate your help!!

print(radius) could it be the csv header line?

I fixed it!! Something weird with the csv expecting more values, so I just put in zeros. Might have also changed a couple of other things in the code. I'll edit with an update.
Thank you!


text:
Object is clipping at certain angles
I want to create a figure in which neurons are shooting out of an image. At certain angles, the objects start clipping. The set of cylinders that represent neurons are clipping. It doesn't matter what angles I change, it still happens. I can change the angle of the image, objects, and camera and same thing. I've also tried changing the clipping distance. Help!
The first image is good except the clipping.
The second image is an angle that didn't clip , but the objects need to be perpendicular to the image.

Please give more details. What objects are clipping? It depends on what angle? camera view angle? Angle relative to another object? What do you mean when you say 'clipping'? What result do you want to achieve and what steps have you taken?
Also might be helpful to post other screenshots of your scene from different perspectives, wireframes, setups, etc.
With the current amount of information you are giving in your question, I doubt anyone would be able to give you a solution.

@AlexandreMarcati The set of cylinders that represent neurons are clipping. It doesn't matter what angles I change, it still happens. I can change the angle of the image, objects, and camera and same thing. I will try to add more info on the post! Thank you.

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


text:
Fitnessbar texture
I have to create a texture similar to this bar https://i.sstatic.net/8SGTN.jpg]1
or this  https://i.sstatic.net/1Maz5.jpg]2 but i can't create something like that with the displace because i have some problems in skretching the textures on the short sides
someone have an idea? thanks
i tried with geometry as you suggested but it doesn't work :(https://i.sstatic.net/23SBj.jpg]4

Could this: https://www.youtube.com/watch?v=BrYrKBAS70Y tutorial help you with the outer material setup?

https://blender.stackexchange.com/questions/84745/create-irregularly-shaped-gaps-in-cube/

Scaling the Normals
Use the Scale node with the Normal attribute and multiply by the bump texture.

hello, thank you!, could you send me your blend file please so i can see better? thanks

Unfortunately, I did not save :/ . https://i.sstatic.net/YDtHC.png Bigger image of the node tree.


text:
Having trouble with Blender and Substance Painter
I'm pretty sure I'm doing something wrong, maybe when creating the UV maps and was hoping to get some help.
As you can see here:  The wood on the front of the house seems ok, but for the wood at the left side it seems like painter doesn't apply the pattern for OR shows the front facing faces of the wood mesh, but it does show the back side of the faces.
I've attached a photo from blender just to get a sense of how it should look:
Update: Seems like mirroring the meshes for the faulty wood bars did the job, but why? Doesn't a mesh keep its properties after being rotated/mirrored?

Select all in Edit mode and recalculate normals (Ctrl+N), then re-export, see https://blender.stackexchange.com/questions/3606/why-are-some-faces-in-my-mesh-darker

@MrZak thanks! I lost the original file wit hthe problems but I'll try it next time


text:
When I try painting a texture with the fill brush i get a weird result
I'm trying something supposedly very simple which is to fill a texture with a color and I seem to get a weird result:

What am I missing here?

The picture you posted is really too small, can't even read it. Please post a normal size picture, and insert it correctly in your post with the picture insertion tool, or using the following code: ![description](link)

@L0Lock wow, you're right, just saw how blurry it was. updated.

Umm not sure if this is a bug of blender. Because I had the same issue too,  so a workaround is using the uv image editor and painting your texture on the image editor directly, avoid painting throught the 3d viewport blender doesnt like it, dont know why. :)
To enable painting on the image editor only change the tab that says view to paint.
Goodluck

Thanks, but i need to paint on the 3d viewport :\


text:
How to debug AN's red boundary box?
What can I do to debug an AN network when I get the red boundary box around my Node Tree?

Red border means a fatal error occured. This is probably caused by a bug in Animation Nodes, however, it may also be an error in your node tree when you disable certain error checking options. In case of a fatal error:

A new panel called the Problems Panel appear. It include some suggestions and an operator to open a new issue on github to report the error as a bug. Choosing Monitor Execution as the Execution Code method in the Developer Panel should present more information in the problems panel like the node that causes the problem.
The error will be printed to the terminal, so looking at the terminal should give you all the information you need, like the node that caused the problem and what exactly is the problem.

It should be noted, however, that some nodes don't have an execution function, and they contribute code to the execution unit directly, thus the terminal output will not be as useful. In this case, the terminal output should be something like:
  File "/home/omar/projects/blender2.80/2.80/scripts/addons/animation_nodes/execution/main_execution_unit.py", line 38, in executeUnit
    exec(self.executeCodeObject, self.executionData, self.executionData)
  File "execution: 'NodeTree'", line 3, in <module>
  File "<string>", line 11, in main

Which tells us that the error occurred in line 3 of the execution code of NodeTree. The Developer Panel have an operator that prints/write the execution code of the selected tree to the terminal/text block, the output should be something like this:
 ...
  9.  nodes = bpy.data.node_groups['NodeTree'].nodes
 10.  _bqracm2qds5y5ta = nodes['Expression']
 11.  __socket_False_0_bqr = None

  1.
  2.  # Node: 'NodeTree' - 'Expression'
  3.  _result_bqr1 = _bqracm2qds5y5ta.expressionFunction()

Line 3 of the execution code lies in the scope of the node called Expression, so we know that this node is the source of the problem.

Such a detailed and informative response! Thank you :)

In my case I couldn't find any error in my AN setup despite the outline being present and the nodes not working, even trying to make a simple frame with a viewer wouldn't work.
After some research I realized I had some old node tree I had totally forgot about, which was indeed the source of the error as removing it made my main tree work again and the outline disappear.


text:
How to generate fake Normal map from an image texture inside Blender Cycles?
Back in a day when I worked with Blender Internal render exclusievely there was a slider called Normals, I simply cranked it up and the texture started to look voluminous. Struggled to find the same thing in Cycles.Any help? Thanks!

I think the bump node is what you want?
Plug the BW output of the image into the hight input of the bump node. Then, feed the bump node's normal output into the normal input(s) of your shader. You can also plug raw BW images into the displacement input of the Material Output. For more reading on the bump node, check this out: How to create normal texture with node setup?

I discovered  bump node but somehow couldn`t get anything from it. Guess my setup was wrong. Gonna try soon , thanks!

Although perhaps not exactly what you're looking for, there are third party apps such as these: https://www.slant.co/topics/4757/~programs-for-making-height-maps-normal-maps-and-or-other-maps#1
I have personally used CrazyBump, and although it seems sketchy, I can confirm that it works. If you use one of these, you have to load in your color (albedo) texture, and it will generate a normal map. You can then load the normal map into blender, and use a normal map node to control its intensity. A bit of a hassle, but this gets the best results that I know of.

Thanks! Some programs are new to me in that list

You have to use Normal maps with the Normal node, and Displacement maps with the Bump node: Create the Normal or Displacement image with a soft like CrazyBump, import it in an Image Texture node, plug this node into a Normal or Bump node, and plug this node into the Normal input of the nodes you want (Glossy, Diffuse...)


text:
how can I render Smoke&fire in Cycles 2.79?
I`m attaching 2 screenshots to illustrate my problem, I made a generic explosion simulation which looks fine in Material\Object mode, and the next screenshot demonstrates what I actually get when trying to render it.
Tried to bake it, changed to CPU, nothing works. Would be glad to know how to solve it]1

You need to provide more information - a screenshot of your material nodes for your smoke domain would be really helpful.

I attached it to my question, but I didnt do anything with them, all by deafault. I mean I only tweaked Particles and Physics tabs just a little bit and thats it

Thanks. The Quick Smoke material is smoke only -  but the final Add node includes a spare socket for ‘flame’ if you need it. See Bigfoot Blondie’s answer for a setup to include flame.

Firstly. Your nodes:

This setup is by no means perfect but it should work. Attach it to your smoke simulation domain.
If that doesn't work, try placing down a single circle, filled. Go to:
Objects --> Quick Effects --> Quick Smoke.
Play animation...
If you render and it works, then there is something wrong with your nodes/object. I recommend trying to recreate your previous attempt.
As annoying as it may seem, you should have a better idea on how to recreate it and will replicate it faster.
If it doesn't work there may be something you have changed in your render settings. Try doing the Quick Smoke method on a new document and see if it works. I still have much learn about blender myself so I can't help you there, sorry.
There shouldn't be any issues with GPU rendering in 2.79.
Good luck, Hope I helped,
BFB

additional nodes didnt change anything. I guess Ill have to recreate it from scratch. In a new project default Quick Smoke does render... Hm just created another new project and it doesn`t render anymore. Such a sorcery

Ahh, yes. I don't use smoke/fire simulations much so I don't have to deal with its nonsense. But with everything I have ever done, If it doesn't work and you hit a roadblock for a while, just start again. This is particularly true with simulations and particles as so many things can go wrong. Again, Goodluck with your projects - BFB


text:
how to tweak the wind affecting the cloth simulation (flag)?
I have a wind blowing onto my flag, looks fine at the beginning but quickly becomes very static so the cloth barely moves. How can I tweak it? I`d like to apply file but cant find where to upload.
Edit
here`s file

Increase Random value or add keyframe to Strength value and in Graph editor assign Noise modifier to this curve. Tweak curvature for desire result.

To append file use  https://blend-exchange.giantcowfilms.com/ and given code place into your original post via "edit".

thanks! Now I know!

Add a wind effect, or try it out with the Stance Simulator, I hope it helps


text:
can I render some elements the way they look in material preview and how to do it?
So I have a a scene and I like some elements displayed in material tab so I want to render those this way. I d like to know how to do it for Cycles or Evee both
Edit: I need it for video

You mean, the Preview  of the Material Properties panel ? You can do a screenshot (either via your OS screenshot tool, or in Blender with Window/Save screenshot) then crop it with any image editor

no, haha. I need a video. Can t do so many screenshots!

In that case you can make a screencast (with a tool like VLC or ffmpeg or whatever depending of your OS). But I guess this is not what you want to do. Could you please be more specific, and show us exactly what you want to capture ? A screenshot would help

well I can t post screenshot because the customer doesn t want it, but I will try to be more specific. I am sure we all remember those days when Blender had an internal render, and it had a OpenGL Render option and it basically just rendered scene depending on the mode (solid, material, etc.). That`s what I want but in new Blender and with Cycles and Evee

Ok you should have start with that ! It's under View/Viewport Render Animation (in the viewport menu). It won't work with Cyles (as in  2.7x) but seems to work with Eevee as far as i know.

thanks! Evee should be enough=)

First, you can do it in the 3D Viewport only. Find a View menu, and click the Viewport Render Animation. It will render the animation right from the viewport, using EEVEE if in solid or material preview mode. If you disable screen overlays, you can easily get nice renders in EEVEE this way, however, this is limited and inaccurate (not enough screen samples will be used, and softshadows can be blurry and flickering, among other limitations).
Here is the place where you can find View menu:

And then, find this menu command:

Thanks a lot!//


text:
Create Seamlessly Looping Animated Displacements
How would one create an animated displacement that could loop seamlessly? In other words, the end of the animation needs to be able to loop to the beginning without a noticeable skip or jump.
The below GIF demonstrates my problem:

See how you can tell when it's transitioning between the last and first frames? That's what I want to avoid.
The method I used to make that animation was to displace a sphere of liquid with a turbulence force field. I am going to assume that it's not possible to create the effect I'm looking for with that approach, and so long as it creates a similar visaual look as the above animation, any methods are good.
In other words, I don't care wether or not I stick to a fluid simulation, so anything works even if it uses shape keys or scripting instead of a turbulence field with a fluid sim.
Thanks in advance!!

Looks like Naruto's Rasengan training. Maybe helpful: seamless ocean

I would have solved it like in the following answer: https://blender.stackexchange.com/a/48915/11287
Instead of displacing the plane, i would have displaced a sphere.

You generate the displacement mathematically by combining multiple Sine waves at different amplitudes, frequencies and orientations. By carefully selecting the frequencies of the waves you can ensure that they all coincide at the start/end so that the animation can be looped.
Here's the result :

This is produced by the following material :

This looks complicated but look closely and you'll see that it is actually made up of 5 virtually identical sets of nodes - to combine 5 waves.
Here the coordinates (adjusted to move the origin to (0.5,0.5) by the Subtract RGB node) are passed through a Mapping node so as to rotate them by a variable amount and this is then separated into its X coordinate (since we only need a linear value per wave). This is then passed through a Multiply node to set the frequency of each 'wave', with the multiplier for each being set to a multiple of 2*pi - this is what ensures the animation will loop correctly. This used to drive the Sine function and scaled by variable amounts (so the different waves have different influences) before being added together and passed to the displacement. The Value node varies the offset between 0.0 (on frame 1) to 1.0 on frame 51, with the animation running from frame 1 to 50 (since 51 should be identical to 1) - ensure to use Linear interpolation on your f-curve for the keyframed Value node.
Play around with the Mapping node orientations and the multipliers (for amplitude and frequency - but keeping the frequencies as multiples of 2*pi!) until you get suitably pleasing results.
Blend file included

OMG you're a legend thank you so much it's perfect.


text:
Motion Capture T-pose Bent At Hips
As part of a larger project, I created a simple human mesh in MakeHuman, enabled MoCap with it in MakeHuman, and imported it inro blender as an FBX file.
When I 'Load and Retarget' the .bvh file I want to use, the model/rig dosn't go into a t-pose as it's supposed to, it is bent at the hips. This totally screws up the animation, as it looks like the figure is always leaning over. This happens with all the MoCap files I try.
I tried going into pose mode and bending the hips back into a normal position, but because the hips are constrained, I can't find a way to do that. I've re-made and exported the .fbx file, and re-downloaded the MoCap files with the assumption that it was just the files that were corrupted, but the problem persists.
Here's a screenshot:

The guide I've been using to do all this is this video by Remmington Graphics.
The MoCap files I'm using come from this site.
What is causing this issue and what can I do to fix it?
Thanks in advance!
Here is the .blend with the extra files packed into it:

EDIT: Here is the MoCap file, a FBX file and a DAE file.
https://drive.google.com/file/d/12RfzXPWZ-7SgoaRTD9LNmtk_bEmFIk0q/view?usp=sharing
https://drive.google.com/file/d/1MD2nwFtcIBvpLKuFYxUMyYAmB6oMREla/view?usp=sharing
https://drive.google.com/file/d/1konpJ3EGeyZH47Zf7OtbTI41O_fSxfqP/view?usp=sharing

Better if you post the bvh and the model separately, without any Blender conversion. So we can check all the chain from the beginning

Ok, I did that.

The video author is using Blender 2.77a, you are using 2.79. This is important since Blender got a few tweaks on importing Collada files.
I am using 2.79b and tried to replicate your problem. I don't get the same problem but I do get issues when importing Collada if I do it the way its done in the video. I was able to solve it with this setting:

This fixed my issues, I hope it fixes yours.
Steps taken:

Exported character from MakeHuman as Collada file with Mocap skeleton
Imported Collada file in Blender with the "Auto Connect" setting
Selected the skeleton. Made sure its in Object Mode
In the MakeWalk v1.1.0 panel, pressed Load and Retarget and selected the Mocap file
Played the animation

It is also worth noting that I downloaded the "Daz friendly" version of the Mocap Files.

Ok, I did that, but now when i go to 'Load and Retarget' it gives me a traceback error. What next?

I got that message as well. When you select the rig, it sometimes goes into Edit Mode. Make sure that the rig is in Object Mode.

The MH model skeleton from the dae model:

The bvh skeleton:

See the position are different. For starters, they have to be the same.
Trying to use the MH load and retarget yields:

It appears there's an incorrect model binding, and a broken starting position...
Normally, you may want to retarget the BVH bone structure to the MH one...
if this yields correct results you're ok then...
If not, then you have to go for the manual bindings... align the bones to the model, fix the starting position, parent the model to the armature (fixing weights if necessary), test the animation.
(By the way, in your original blend the model seemed to walk and jump a ledge, while this animation show a hand-walking exercise. Sure they are the same?)

Oh it might be that I selected the wrong file oh well


text:
Changing camera location in script and rendering - problem with keyframes resetting the location before render
What I do is that I change the camera location in Python API and render a new view. Here is an example:
import bpy
import copy
import os

#backup
camera = bpy.context.scene.camera
originalCameraLocation = copy.deepcopy(camera.location)
renderInfo = bpy.context.scene.render
originalPath = copy.deepcopy(renderInfo.filepath)

cameraStep = 0.2
stepCount = 5
#iterating and shifting the camera along X axis + render
for i in range(0,stepCount):
    camera.location[0] += cameraStep
    renderInfo.filepath = os.path.join(originalPath, str(i))
    bpy.ops.render.render(write_still=True)

camera.location = originalCameraLocation
renderInfo.filepath = originalPath

This is working fine until I use keyframes to animate the location of the camera. No matter where I put them. This is the standard behavior in Blender, I am aware of this. Blender resets the given attribute according to the keyframes before rendering.
I would like to seamlessly integrate the animation into my logic. My goal is to get the current camera location as the initial one in my loop (affected by the animation if keyframes are present) and make the shifting relative to that. This is probably working when I simply do this, right?
bpy.context.scene.frame_set(currentFrame)
animatedLocation = camera.location

The issue is that the line:
camera.location[0] += cameraStep

in my code does nothing due to the position reset before rendering. Is there any way to disable this resetting or temporarily disable the whole animation just for the rest of the loop? So basically having the loop like this:
#this should be affected by the keyframes
currentFrameCamera = copy.deepcopy(camera.location)
for i in range(0,stepCount):
       currentFrameCamera += cameraStep
       ...disable the keyframes so the new location reaches rendering...
       camera.location = currentFrameCamera
       ...rendering...

I can think of inserting a new keyframe every time I change the location but I'd need to backup the possible existing ones, restoring them afterwards etc. That feels a bit hacky. Another, probably better solution would be to create a new camera or rather duplicate the existing one, removing the animation keyframes there, setting the location, setting the new camera as active, and removing it after render. I would like to discuss which solution is optimal or if there's something better to do. Thanks!

Creating a new camera is, imho, a clean and easy solution. Just be careful : if you copy the camera then delete keyframes, they will be deleted for the first camera too (because they share the same Action). You should unlink the Action from the new Camera (with something like "myNewCamera.animation_data.action = None")

Thanks @thibsert for the information about the Action. That would probably give me a lot of headaches before finding out :D. I guess I will go for the new Camera solution then.


text:
Limit "prop_search" to Specific Types of Objects
Currently working on a piece of custom UI that contains an object selection box.
layout.prop_search(scene, "myselection", scene, "objects")

I'm wondering how I can make it so it only lists objects that contain a certain data type such as curves in the same way that the Follow Path constraint does.

Thanks for your assistance.

Since blender 2.79 this is possible using the poll parameter of the bpy.props.PointerProperty.
import bpy

class OBJECT_PT_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
        scene = context.scene
        layout.prop(scene, "mychosenObject")

def scene_mychosenobject_poll(self, object):
    return object.type == 'CURVE'

def register():
    bpy.utils.register_class(OBJECT_PT_HelloWorldPanel)
    bpy.types.Scene.mychosenObject = bpy.props.PointerProperty(
        type=bpy.types.Object,
        poll=scene_mychosenobject_poll
    )

def unregister():
    bpy.utils.unregister_class(OBJECT_PT_HelloWorldPanel)
    del bpy.types.Scene.mychosenObject

if __name__ == "__main__":
    register()

See the documentation

bpy.props.PointerProperty(type=None, name="", description="", options={'ANIMATABLE'}, poll=None, update=None)

Returns a new pointer property definition.
Parameters:

type (class) – A subclass of bpy.types.PropertyGroup or bpy.types.ID.
name (string) – Name used in the user interface.
description (string) – Text used for the tooltip and api documentation.
options (set) – Enumerator in [‘HIDDEN’, ‘SKIP_SAVE’, ‘ANIMATABLE’, ‘LIBRARY_EDITABLE’, ‘PROPORTIONAL’,’TEXTEDIT_UPDATE’].
poll (function) – function to be called to determine whether an item is valid for this property. The function must take 2 values (self,object) and return Bool.
update (function) – Function to be called when this value is modified, This function must take 2 values (self, context) and return None. Warning there are no safety checks to avoid infinite recursion.

Pass the right collection, in this case bpy.data.curves:
import bpy

class OBJECT_PT_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
        scene = context.scene
        layout.prop_search(scene, "mychosenObject", bpy.data, "curves")

def register():
    bpy.utils.register_class(OBJECT_PT_HelloWorldPanel)
    bpy.types.Scene.mychosenObject = bpy.props.StringProperty()

def unregister():
    bpy.utils.unregister_class(OBJECT_PT_HelloWorldPanel)
    del bpy.types.Scene.mychosenObject

if __name__ == "__main__":
    register()

Explanation: How to make my prop search show the objects in my scene?

Sorry if I wasn't clear enough, I want the list to only display objects that have curve data, not the curve data itself.


text:
How do I run a script on multiple .blend files from the command line?
Problem: I have a bunch of .blend files that I want to make the same changes to as quickly as possible.
Solution: Run a python script on each file from the command line?
Here's the python script I'm currently using:
import bpy

#show all layers
bpy.context.scene.layers = ((True,)*20)

#delete the camera, sun and ground
for obj in bpy.data.objects:
    obj.select = False
    if obj.name == "sun":
        obj.select = True
    elif obj.name == "ground":
        obj.select = True
    elif obj.name == "camera":
        obj.select = True
    bpy.ops.object.delete(use_global = False)

#adjust object locations
for ob in bpy.data.objects:
    ob.location[0] = ob.location[0] / 10
    ob.location[1] = ob.location[1] / 10
    ob.location[2] = ob.location[2] / 10

#save the file and quit
bpy.ops.wm.save_mainfile()

And here's the .bat file:
cd C:\Program Files\Blender Foundation\Blender

blender -b "C:\[path]\file_01.blend" --python "C:\[path]\adjust.py"
blender -b "C:\[path]\file_02.blend" --python "C:\[path]\adjust.py"

The python script works inside Blender, but when I run the .bat file (in admin mode) it just closes. What am I doing wrong?
Bonus: Is there a way to simplify the .bat script so that it just runs on every .blend file in the folder without them being typed out?

You can check if there is any error by running it from direct commandline, I think, but I will try to run it from my computer also.

By the way is script working in Blender when you try to run it manually?

Originally, no it wasn't working (I was thinking of a different script when I posted this). I've corrected it now (and updated my post), so the script definitely runs in Blender from the text editor but the problem of running it from the command line persists.

Try using forward slashes in your path. Backslashes have different meanings in different environments, so are often a cause of trouble. You also don't need to specify the full path, relative paths are fine too.

No change when using forward slashes.

There is nothing wrong with either script. The problem was the use of an ampersand (&) in the file path. Don't use special characters in your folder/file names. Newbie mistake on my part.

I put up together an Autohotkey script that does exactly that (requires Windows and Autohotkey v1 installed)
https://github.com/Flowgun/BlenderBatcher

While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference.  Link-only answers can become invalid if the linked page changes. - From Review


text:
Blender Principled BSDF shader missing, please help
The Blender Principled BSDF shader is missing in my node editor. I'm using the latest Blender version 2.79. Please help :)

You need to switch to Cycles rendering engine to be able to see/add Principled BSDF shader:


text:
Material shown in material mode but not render mode
I have material which is attached to my object and it is seen normally when i am in object mode/mateiral

But when i go into render mode i get object without material:

As you can see also in material preview it is gray.
It is cycles render.

Node setup is incorrect, use MixRGB instead of Mix shader. Green and yellow sockets are incompatible


text:
Faces won't appear regardless of it being in wireframe or solid

So as you can see the faces are there, but the object is not in wireframe. It is in solid. How do I make it so the faces appear? I have tried alt+H and pressing z too many times to count.

perhaps in the Object menu > Display > Maximum Draw Type, switch from Wire to Solid?

@moonboots omg thank you I saw that on a different post and I couldn't find display in the object menu so I ignored that idea. Turns out I was looking in the wrong object menu. I thought it was the drop down object menu on the view/select/add/object bar so yeah my bad sorry

@cegaton yes but their question is possibly very misleading so in case anyone has this question in the future it is best to leave this question up so they actually get the answer they’re searching for.

In the Properties > Object menu > Display > Maximum Draw Type, switch from Wire to Solid


text:
Render multiple Layers, how to mix/combine them, it's not working here
I am startup up with Blender and through an internet course I created a scene, which are heavy to render on my pc.
So I started to investigate Render Layers, ideal for my situation I thought, I can render each Layer at a time, also on different computers and eventually combine al rendered images together, to created a final Rendered masterpiece.
I am figured out that I have to set Transparency on, on all images.
So I did.
And for the background (World), which will be displayed on the back, with everything in front of it, I figured Transparency is not needed, so I rendered an empty Layer with the Environment setting on.
I now have 3 images to start with, more Layers will be rendered in a later stadium.
So I find out that I have to use the Node Editor with a box called Alpha Over to combine them, so I did, see screendump picture.

But the problem is, my combined end result is not showing anywhere.
What am I doing wrong, is my approach not right, I'm kinda stuck here.
Help would be much appreciated!
Regards
Martijn.

It worked. I rendered 3 layers and in the node editor I checked use nodes and backlog.
And then using alpha over I combined them and the result was shown :


text:
How can I rig a cylinder so that when it's rotated its end cap will not penetrate the floor?
I have a default Blender cylinder positioned upright atop a ground plane:

How can I rig the cylinder so that can be animated to wiggle/jitter (perhaps procedurally with noise f-curve modifiers on two of its rotation axis) without penetrating the floor?

A simple parent-child relationship as in the image above is sufficient to rotate (and translate) the cylinder on 1 axis in either a positive OR negative direction.
I'm looking for a setup that would allow me easily to rotate the cylinder on two or even three axis in both a positive and negative direction.
I imagine this would be possible with some drivers applied to the XYZ coordinates using trigonometric equations but the math escapes me. It might also be possible using a particular bone setup with the correct constraints but my attempts to find something that works so far have not succeeded.
Thanks for your assistance.

Related https://blender.stackexchange.com/questions/42144/rolling-cube-animation-how-to https://blender.stackexchange.com/questions/7183/how-to-animate-a-cube-pivoting-more-than-once-without-affecting-its-original-po https://blender.stackexchange.com/questions/143046/how-can-i-roll-a-cube-around-its-edges-with-armatures https://blender.stackexchange.com/questions/69731/rotate-a-cube-on-a-plane-using-drivers https://blender.stackexchange.com/questions/119677/how-can-i-rig-a-cylinder-so-that-when-its-rotated-its-end-cap-will-not-penetrat

There is no need for complicated trigonometry or drivers. You can do this with constraints.
Constraints are faster than drivers and have no security problems (manual).

The Cylinder Rig
Create the following bones. (Side view. Note, that the orientations of the bones are all the same.)

CTRL_cylinder has no parent or child. The other bones are in the following hierarchy:
floorRotation > orientation > DEF_cylinder > Cylinder (object)

Add a Copy Rotation constraint from CTRL_cylinder to DEF_cylinder.
Add a Copy Rotation constraint from CTRL_cylinder to orientation.

Add a Locked Track constraint to orientation. The Target is CTRL_cylinder, with Head/Tail at 1. Set the To field to -Z and Lock Y.

Add a Copy Location constraint from CTRL_cylinder to floorRotation.
Add a Locked Track constraint from CTRL_cylinder to floorRotation.
Yet again, Head/Tail is at 1. Set the To field to Y and Lock Z.

I suggest the rotation order YZX for CTRL_cylinder. Add a crazy control shape for CTRL_cylinder and set it to be displayed At DEF_cylinder. The animator can move, rotate and roll the cylinder. Optionally, the Y axis can be locked, if no twisting is desired.

BONUS CONTENT
Two Axis (Rocker) Setup
This is useful for objects with two or more pivots, like feet, chairs, ... or a cube.

Create the following setup. The CTRL_cube is not in the hierarchy. The other bones are parented as such:
y_copy > frontPivot > backPivot > DEF_cube > Cube (object)

The rotation order of CTRL_cube is XYZ with Z locked.

Add a Copy Location constraint from CTRL_cube to y_copy.
Add a Copy Rotation constraint from CTRL_cube to y_copy with only Y checked and Local Space for Target and Owner.

Add a Copy Rotation constraint from the CTRL_cube to frontPivot.
Add a Copy Rotation constraint from the CTRL_cube to backPivot.

Finally, limit the rotation of the frontPivot, to prevent the cube from going under the floor.

Add a Limit Rotation constraint to the frontPivot in Local Space, For Transform and with the X Limits 0 and 90.

The result can be moved rotated and rocked from front to back. With additional pivots and their respective Limit Rotation constraints any number of edges can be available for rocking.

Added a stylisch Bone Shape for CTRL_cube At DEF_Cube.

This is fantastic, exactly what I need! Thank you! I cannot award the bounty for another 13 hours but will do so then.

@BlenderBro Leave the bounty open, someone could come up with an even more fitting answer.

It doesn't seem you would need complex trigonometric equations here. You only wish to keep the object above ground(or on the ground), let's do just that.
Using a Driver
You can set up a driver for z location with a scripted function that finds the lowest vertex and then adjusts the location of the object accordingly:
import bpy

def aboveGround(object_name,floor_z):
    obj = bpy.data.objects[object_name]
    mesh = obj.data
    z = 7 # because it's a lucky number...
          # ...and 0 seems to be buggy inside the driver for some reason
    for verts in mesh.vertices:
        world_space_co = obj.matrix_world * verts.co
        if world_space_co[2] < z :
            z = world_space_co[2]

    loc_z = obj.location[2]

    return loc_z - z + floor_z
#    # or this if we don't want the object to stick to the ground when it's above :
#    if z<floor_z:
#        return loc_z - z + floor_z
#    else:
#        return loc_z

# add function to driver_namespace
bpy.app.driver_namespace['aboveGround'] = aboveGround

You would need to have this in a text block and check Register (Autorun Python Script will need to be enabled in the user preferences as well) so it runs when you open the file:

You can just run it manually as well.
Then you can create a driver for z location of your object and put the function as the expression:

Using a Scene Update App Handler
It would also be possible to have only a function that would correct the position while working so you could set keyframes. Sort of like a tool. You could use a scene update app handler for that. You could just register it when you need it and then remove it once you don't need it any more:
import bpy

def AboveGroundHandler(scene):
    obj = bpy.data.objects['Plane']
    mesh = obj.data
    floor_z = 0
    z = 7
    for verts in mesh.vertices:
        world_space_co = obj.matrix_world * verts.co
        if world_space_co[2] < z :
            z = world_space_co[2]

    obj.location[2] = obj.location[2] - z + floor_z

bpy.app.handlers.scene_update_pre.append(AboveGroundHandler)
#bpy.app.handlers.scene_update_pre.clear() # to remove it(can be run from Python console)

Thanks for great script! I want to say, if driver expression produces error after opening a file, just add ".py" after script name in text editor (w/o quotes)

(I wrote a trig. version of your driver, but for cylinders only, so it's not as general as yours, and  not worth posting.).. What triggers  a scene_update_pre handler? Would it work during interpolation between key frames?

I believe drivers are intended for use in animation, I think it would be better to use them. I just thought, that if there is a cylinder wiggling it might bounce up and down so if one wanted to animate it manually, that could be simplified using this handler method as a simple tool for just placing the object in correct positions while the keyframes are set - that was the thought process. I think it might lead to unexpected results if used in animation.

A really interesting, general purpose solution, thank you! I gotta go with Leander's constraint setup though due to its comparative ease of use, and for the reasons stated at the top of their answer.

Leander's solution is really great. That would probably be my choice as well. I don't do much animation, so I did not think of it.


text:
Find missing file via commandline
The problem is simple. I created some compositing projects with many input files from different places distributed on the hard disk. I want to render the final projects on another pc, but don't want to restore the original folder hirachy with all the sub folders. So I've planed to copy all raw material into one folder on the 'render pc' and let blender search there for missing files - automatically, because the target OS is non-graphical.
I would be delighted if somebody could help!
Julian

Can you be more explicit? Show an example of full paths to files on the source machine and the destination path on the destination.

@glennjackman I'm using some Movie Clip nodes as input. A example path is //..\raw\cam4\c4_C0030.mp4 or //...\footage\nature\treesky.mp4 (at Win). At destination:  //./mixinput/c4_C0030.mp4. Do you mean that?

Using python you can change the filepath stored for every movie clip. You can do this before saving the blend file onto the remote machine by pasting the following into blender's text editor and clicking the run script button.
import bpy, os

for m in bpy.data.movieclips:
    m.filepath = os.path.join('//mixinput', os.path.basename(m.filepath))

Then when you open the blend file on your remote machine, blender will look for the movie clips in the mixinput folder located next to the blend file.
If you want to do it on the remote machine you can add bpy.ops.wm.save_mainfile() to the end of the above script and save it to a file next to the blend file, then use
blender -b myfile.blend -P myscript.py

The same can be used to adjust VSE clips by changing the for loop to
for m in bpy.context.scene.sequence_editor.sequences:

or for all images using
for m in bpy.data.images: