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Getting rid of texture bleed from opposite edge
I'm using Blender 2.76b with the internal renderer. Whenever I render a simple plane with a texture applied to it, I get a small border on the edges that consists of a mix of the expected texture color and the color on the opposite end of the texture. The same thing happens when using the add-on called "Import Images as Planes".
The texture settings I've tried so far:

Enabling and disabling repeat
Disabling Mip Map
Disabling Interpolation
Different filter types
Filter Size 0.10
Enabling Minimum Filter Size

The filter size seems to have the biggest impact but even the lowest possible value doesn't get rid of it entirely. See the example on the lower left for best visibility:

Blender files:
One way I could think of to fix it would be to add some empty space around the texture image. But since I'll be using my objects outside of Blender and I haven't encountered this elsewhere, I'm a bit hesitant about the wasted texture space. Is there any other way to fix this?

Pictures are your friend, please add as much relevant information as possible so that people wanting to help can do so without guessing at what's on your screen.

@Timaroberts Thanks for your advice. I've added a picture and rephrased some parts.

I am assuming you also have these simple .blend files you already set up to test render. Wouldn't harm to load the .blend files so we could examine them with less assumptions and more accuracy to the issue on hand.

@hawkenfox Good idea, thanks. I've added them to my question.

Try playing with the 'Image Mapping' in the Texture panel. If you change the 'Extension' from Repeat to Clip, the edge gets blurred with the background. Choosing 'Extend' yields a harder edge on the outside.
Extension set to 'Clip':

Extension set to 'Extend':

Ah, that's exactly the setting I needed, thank you! And thanks for also taking the time to show the difference between clip and extend.

@Eric You're welcome. The repeat option is actually pretty nice if your working with tiled textures. Checkered.... ? no idea.


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Cloth simulation presets are gone, how do I get them back?
I'm trying to use one of the cloth presets in the Simulations tab, but I've accidentally deleted a couple of the presets and I don't know how to get them back. I've tried restarting blender with a new file, but the cloth sim. still didn't have the Presets. And I even Tried to Load Factory Settings as proposed in this answer as well and it still wouldn't work! If anyone can tell me whats going on, that would be great. Thanks!

I had this problem. Blender hides options depending if you are in Blender Render Mode, Cycles, or Game mode. Its kind of frustrating actually.

It's probably easier to just tell you what the default presets are:

Cotton: Steps 5, Mass 0.3, Structural 15, Bend 0.5, Spring 5
Denim: Steps 12, Mass 1, Structural 40, Bend 10, Spring 25
Leather: Steps 15, Mass 0.4, Structural 80, Bend 150, Spring 25
Rubber: Steps 7, Mass 3, Structural 15, Bend 25, Spring 25
Silk: Steps 5, Mass 0.15, Structure 5, Bend 0.05, Spring 0

These are as of 2.77.

Have you tried reinstalling Blender? (I guess if you have a complex start-up file it would make sense to save a copy of that before reinstalling.)

source: Stack Exchange

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

sort: votes


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Glossy Shader not working to create realistic texture as I wanted it too
I'm trying to use the glossy shader to create that realistic effect on real world objects, but it seems as though if the glossy shader is not working as I please.
This is what it looks like:
I'm trying to give it a white reflection over the orange, but I'm not sure if i have to put something into the glossy shader, but I don't know.
Thanks if you know what i should do.

To get a nice reflection you'll want to add

More light
Materials, especially glossy or refractive materials, are hugely dependent on the surrounding light sources. Try adding a nice big mesh light (or area lamp) for the material to reflect
Fresnel
Light tends to reflect off of materials more at glancing angles, and reflect less when hitting a surface straight on. If you look at your top-down reference picture/texture, there is hardly any visible specular reflection ("specular" refers to perfect or mirror-like reflections, such as the sharp white highlights)
To simulate this, add a Fresnel node, plug your bump/normal map into it, and connect it to the Mix factor of the mix node which is mixing in your glossy shader.
This will make a big difference, especially on surfaces with lots of small variations in angle.

In this example I slightly complicated things by giving the rind a lower IOR than the rest. A more simple setup could just connect one of the fresnel nodes straight to the mix shader (both selected). However given that the rind and fruity parts of the orange have quite different optical properties, you probably do want to simulate that in some way.

Note that an actual orange is quite complex, with the fruity parts being translucent with a visible internal structure. To properly simulate one, you might want to model the slices and rind separately and use a translucency, SSS or volume shader (somewhat similarly to this).

When dealing with concepts of "whiteness" in @gandalf3's reply, it is worth realizing that they are display referred concepts. This means dynamic range also plays a role in your rolloff to white in the display referred domain. See http://blender.stackexchange.com/questions/46825/render-with-a-wider-dynamic-range-in-cycles-to-produce-photorealistic-looking-im/46940#46940 if this is alien to you.

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


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Apply as rest pose deforms the animation
I am trying to apply skeleton to model. I can import BVH and see the animation just fine, however when I do "Apply as rest pose" which is necessary for the model to actually align with the skeleton's movement, the animation becomes completely distorted.
If I don't apply the rest pose the model gets distorted the moment I parent the model and skeleton.
What am I doing wrong?
EDIT:

Are you applying the rest pose when the skeleton is in a similar position to the mesh?

yes. actually the strange thing is that the moment I apply rest pose, the actual skeleton animation gets completely messed up

Can you post a .blend on http://blend-exchange.giantcowfilms.com/?  Its too hard to tell what might be going on without a .blend to look at.

Uploaded! Sorry I can't add the model, but even with BVH it will  be obvious what's wrong - the "rest pose" completely messes up animation. Thank you!

Wow -- yeah the default pose in edit mode is all 'condensed' into a little chain.  Honestly I've never seen anything like that.

ugh.. any idea why it can happen?

Sorry no.  I'd look at how you generated the bvh.

Old blender artist thread to change the animation of bvh after changing rest pose.
http://blenderartists.org/forum/showthread.php?254060-modify-motion-capture-T-pose
The code in a zip file
http://blenderartists.org/forum/attachment.php?attachmentid=283112&d=1389806292
The concept~~

Pose the armature into the new rest pose.
Make a copy of armature and make the pose the copies new rest pose.
Join the two armatures
Use the bone snapping code from rigify to snap the copied bones to
the original bones, and keyframe the new animation from those.

run the script and you will get the following buttons in the armature data panel

Hit the New rest pose to rig button, this will give you a new set of bones to the armature.  Have a look at the rest pose, the new set has the pose as a rest pose.  Play the animation and you will see the new bones do nothing.
EDIT
The execute of the operator updated to 2.8,
import bpy
from bpy import context

###################################################
# dupe rig
# for copy
# add prop to point to original bone
# make current pose the rest pose
# join to original
####################################################

scene = context.scene

# original bvh rig
bvhrig = context.active_object

bpy.ops.object.mode_set() # object mode
bpy.ops.object.duplicate()
ob = context.object
print("DUPE", ob)

#add a custom prop for each bone in the copy

for bone in ob.pose.bones:
    bone['bvh'] = bone.name

# apply the pose as rest pose
bpy.ops.object.mode_set(mode='POSE')

bpy.ops.pose.armature_apply()

bpy.ops.object.mode_set(mode='OBJECT')

# join back to original
ob.select_set(True)
context.view_layer.objects.active = bvhrig
bvhrig.select_set(True)

bpy.ops.object.join()

The BVH action to new restpose rig button, copies the original's animation by snapping the bones for each frame of the action.  Play the animation now and the new bones are animated same.
Then lastly, copy, paste, n run this code
import bpy

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

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

    def execute(self, context):
        #dupe the armature
        bpy.ops.object.mode_set(mode='OBJECT')
        bpy.ops.object.duplicate()
        newarm = context.object
        # copy the action
        newaction = newarm.animation_data.action.copy()
        # strip out the old fcurves
        for fcurve in newaction.fcurves:
            if fcurve.data_path.find(".001") == -1:
                newaction.fcurves.remove(fcurve)
            else:
                fcurve.data_path = fcurve.data_path.replace(".001","")
        newarm.animation_data.action = newaction

        bones = [bone.name for bone in newarm.pose.bones if bone.get('bvh') is None]
        # remove original bones
        bpy.ops.object.mode_set(mode='EDIT')

        arm = newarm.data
        for name in bones:
            eb = arm.edit_bones.get(name)
            if eb is not None:
                arm.edit_bones.remove(eb)

        # rename bones to original names
        bpy.ops.object.mode_set(mode='POSE')
        for pb in newarm.pose.bones:
            pb.name = pb["bvh"]

        return {'FINISHED'}

def register():
    bpy.utils.register_class(SimpleOperator)

def unregister():
    bpy.utils.unregister_class(SimpleOperator)

if __name__ == "__main__":
    register()

    # test call
    bpy.ops.object.simple_operator()

and you will have a new rig (single bone set) with the new animation and new rest pose.
As you are using the Male1__.bvh mocap set, you can use the same "double boned" rig with other actions imported from another file of same mocap subject.
Result.

When applying a new rest pose, the blender console states: Actions on this armature will be destroyed by this new rest pose as the transforms stored are relative to the old rest pose. So you might have to redo your animation, or work with a model that is posed according to the animations rest pose. The rest pose of your animation is totally weird though.

I see. I exported BVH from MotionBuilder. Any chance you'd know of any gotchas related to that?

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


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Baking Models with AO
Recently I have been working on an aircraft that has been a little project of mine, and I have wanted to bake the AO onto it.

The first picture is what happens when I bake it. While the second one is what I want it to look like. As you can see there is a weird black spot and to the right of it a spot that is darker then it should be. The same with the nacelle under it, the nacelle appears slightly darker then it should be. The bottom picture is of the aircraft with the viewing AO in the shading menu, I just want what I see in the shading menu to be perfectly put onto my UV map.

A few things could cause this, from a bad UV unwrapping job to duplicate vertices and inverted normals.

If you're still looking for an answer, is it possible you could upload part of your .blend? (just the enough to demonstrate the issue)

I would agree with HATMAN - Possibly inverted Normals or doubles. Go into Edit mode, Press W - Remove doubles (also available from the tool menu on the LH side). Along the bottom menu, you can also recalculate normals by going to mesh> normals>recalculate outside . They should help.
When you do these, take note of the top bar (where it says the amount of tris etc), and it will tell you if it had to remove doubles etc..

I just did that and although it did remove the doubles, the texture now doesn't show the spot as black, which is good, it shows it with an AO baked object, that part of the object still appears black even though the texture is not, and it is not a problem with the UV mapped because it has been UV unwrapped by a pro and has been textured many times.

@JordanPalmer Are there any overlapping UVs? Often different parts of a model are mapped to the same spot in order to re-use parts of the texture, however this doesn't work with baking. If the UV professional didn't think the map would be used for baking, it's possible..


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How to create a procedural chevron like texture/material?
I'm playing around with nodes within cycles and I'd love to create a chevron like texture like the image below. Anyone an idea how to accomplish this?

How's this?

Accidentaly made this: https://i.sstatic.net/L1XKe.jpg it's pretty I don't want to delete it :)

Start with Wave procedural texture and create tiling in X axis with Repeating patterns on procedural textures. After that clamp the values into stripes with a ColorRamp node set to constant:

 (^click to enlarge)
You can adjust the stripes with the ColorRamp node:

For mapping procedural textures onto spherical objects there has to be additional transforming of mapping coordinates:
For procedural cylindrical projection this node group:

And for procedural spherical projection this node group:

Using the spherical projection with the tiled chevron procedural texture:

Here we also added an extra Mapping node to control stretching of the texture around the surface.
Download the .blend file with append-able node groups here:

On the egg shape cylindrical projection looks the best:

Jaroslav, do you have a channel in Youtube?

@RitaGeraghty I do, but with no 3D content or tutorials.


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"Parsing error" When trying to import a DAE file I found on the internet
I found a file on a trusted site one the internet, but when I downloaded it and tried to import it to Blender 3.0, (Macbook) it says "Parsing errors in Document (see Blender Console)" I tried it on another document and got the same thing.
Both documents were "Whatnot_OpenCollada.DAE" if it helps.

First, update Blender. Second, if you still get the same error, do what it recommends and look at the console. You can toggle it on and off in MS Windows via an option in Blender’s Window menu.

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


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why did my keyframes disappear in the graph editor when they show up in the timeline?
I have the camera selected, but I don't seem to get why they are gone. I also dont have the only show errors option selected.

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.

the timeline or dopesheet only show the keyframes of objects you have selected. if you added keyframes for the default cube, you have to select it to see the keyframes. if you added keyframes for the camera, you have to select the camera. if you want to see all keyframes, select all objects with keyframes.

Bear in mind that the keyframes are linked to a specific object in the scene.
When you say that you have the camera selected, then the only keyframes in the timeline and in the Graph editor that will be visible will be those relating specifically to the camera, thus the first question for you is
Are the missing keyframes in the graph editor specifically tied to the camera, or to some other object in the scene?
If they are keyframes for camera animation then, then it might mean that you need to scale up or down in the graph editor to make them visible. If the missing keyframes are tied to the animation of another element in your scene, then you must select that item (I usually select it from the outliner) in order to see them in the graph editor.
Since many items in a scene can have their own key frames, it may not be immediately clear that you have the correct item selected.


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How do I get two different displacements to follow a texture mask
Hi I'm pretty new to this. I made one textures and downloaded another off of Polygon and I figured out how to use a texture mask to paint what part of my object has one texture and what part has the other (grass and dirt). However I can't get the same to work with displacement. The grass has very specific displacement pattern and I don't want that showing up where the dirt is supposed to be. I can't figure out how to get the displacement to follow the texture mask as well. I tried plugging the two displacements through a MixRGB and then into a displacement but the dirt still had the grass texture in material preview and in render it looked like the photo I linked so no luck there.

if you are posting a picture of your node tree next time, please make sure that we can read it. Thank you. It might be helpful if you just paste more image so you don't run into the "picture too big" problem.

you can try out this setup here:


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FOV not matching projection matrix
I'm trying to write custom OpenGL renderer that produces the exact same images as blender. However I struggle with getting camera right.
I duplicated this code and I managed to produce the exact same matrix as in calc_matrix_camera
render = bpy.context.scene.render
depsgraph = bpy.context.evaluated_depsgraph_get()
proj_matrix = bpy.context.scene.camera.calc_matrix_camera(depsgraph,x=render.resolution_x,y=render.resolution_y,scale_x=render.pixel_aspect_x,scale_y=render.pixel_aspect_y)

I get the model-view matrix identical as in bpy.context.scene.camera.matrix_world but for testing purposes I always place camera at the origin point with no rotation (so model-view matrix is the identity matrix). However I still cannot get the renderings right. What I find suspicious is that
bpy.data.cameras['Camera'].angle_y

returns a different value from
2.0*math.atan( 1.0/proj_matrix[1][1])

(explanation of math here). I suspect there is some extra logic that I'm not taking into account. How do I get aspect ratio and fov from blender? Which of those values is correct?

There is indeed some extra logic. In general you should use camera.angle and take the settings under Camera Properties > Camera > Sensor Fit into account.
Lets set first
camera = bpy.data.cameras['Camera']
aspect = render.resolution_x / render.resolution_y

If the Sensor Fit is set to Horizontal you'll have (equaling angle_x)
camera.angle = 2.0 * math.atan(aspect / proj_matrix[1][1])

If it's set to Vertical you'll get (equaling angle_y)
camera.angle = 2.0 * math.atan( 1.0/ proj_matrix[1][1])

Finally, if it's set to Auto it depends on the aspect ratio:
If aspect > 1 then camera.angle = camera.angle_x = 2.0 * math.atan(aspect / proj_matrix[1][1])
If aspect < 1 then camera.angle = camera.angle_x = 2.0 * math.atan(1.0 / proj_matrix[1][1])
If aspect == 1 then camera.angle = camera.angle_x = 2.0 * math.atan(aspect / proj_matrix[1][1]) = 2.0 * math.atan(1.0 / proj_matrix[1][1])
For an in-depth explanation on what Blender is doing under the hood see my answer here.


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Blender Sequencer speed is Extremely slow
I have a video (720p) that is 37 minutes long, with a bitrate of ~3000kb/s.
This video is a game recording, so 37 minutes worth of this footage was written in 37 minutes, while other extremely CPU, GPU and hard-drive intensive operations were occurring.
If the recording program can record and output at the same rate as is being played, I don't understand why rendering with blender at the same exact settings, same codec, same container type, same bitrate and size, the only difference being that I removed about 4 seconds from the beginning, is going to take 5.3 hours to render.
I've disabled every feature under user preferences that are said to increase performance, I disabled rendering of the 3D scene (which is empty anyways). I set the sequencer memory cashe limit higher, I've increased the number of prefetch frame which is supposed to help with multicore rendering.
What else can I do to make the rendering faster? I've used blender for years for 3D, and I'm getting into recording videos for YouTube, all the good programs for video editing are very expensive. But those programs can render 37 minute videos in 10-20 minutes, not 5.3 hours. I don't understand why it's so slow, it's so slow to the point it's unusable.
Replies to Comments
@user277143: My guess: try increasing the cache of blender itself too (alongside the Sequencer's cache). Also, having meshes in the scene will cause them to be reloaded for every frame. That can cause problems. So, go to the 3D-view and delete everything. Also, off topic, check the resolution multiplier in the render settings. I have screwed up many sequence renders by having it at 50%.
I have already done the cache of Blender as well. I already have nothing in the 3D scene, and I even have that entire render layer disabled in the outliner.
@gandalf3: Related:

How to make VSE render faster?
VSE suddenly slow like hell
Poor performance with h.264 VSE
How to speed up Blender Video Sequence Editor rendering?
Is the VSE multi-threaded?

I've seen all of those, none of them provide any help that has altered the result. Those issues were due to bugs, or a settings issue. In the past I've been able to render at around 50-60 outputted frames per second, so rendering a 30 minute video in 15-18 minutes. Only in the last 3 weeks has this started to take this long, so there is a way somehow to speed it up, and I haven't touched any settings on the program.

My guess: try increasing the cache of blender itself too (alongside the Sequencer's cache). Also, having meshes in the scene will cause them to be reloaded for every frame. That can cause problems. So, go to the 3D-view and delete everything. Also, off topic, check the ressolution multiplier in the render settings. I have screwed up many secuence renders by having it at 50%.

Related: http://blender.stackexchange.com/q/7738/599,
http://blender.stackexchange.com/q/15835/599, http://blender.stackexchange.com/q/27855/599, http://blender.stackexchange.com/q/27007/599, and http://blender.stackexchange.com/q/19627/599

Just get Fusion, it's free. It's like Nuke or AfterFX. Don't use Blender sequencer, as you said it's useless when Fusion is free.

Addressed the comments at bottom of question.

@D3_JMultiply If it's slowing down for no reason (identical setup performs significantly faster in old version than latest version), then that sounds like a regression which should be reported.

That's the thing, it's also the same version. Been using 2.74 since it came out, I know 2.76 is out, just never upgraded, maybe upgrading will have performance increases. For now I don't really struggle too much with the render time, I just render overnight.

Have you recently checked Antialiasing? It needs quite some performance. Is your input and output resolution the exact same? Scaling every frame takes time as well. When you Crop/Offset your footage, will it move our stay at its place? Does this help? Is your footage on a fragmented hard drive? Can you unchecked Compositing in your Render Settings? Have you tried a test render in a fresh factory reset startup file? Try upgrading to a recent build as there have been some VSE performance improvements lately.

Any updates to this question? It'd be nice to get it off the "unanswered" list.

@Matt No, feel free to close this if you wish. I was mostly trying to figure out why it's so slow. i mean the Blender Foundation uses the sequencer with their own open movie projects, so i don't understand why it would be so under-optimized. It's not that hard to process frames, so I simply don't get what the sequencer is doing that makes it so slow.

@cegaton I've tried a lot of software, and all free ones I can find always seem to have issues. That's why i tried Blender, because it's a software I've used for over 12 years. I'll check out Resolve though, thanks.

@cegaton yeah, I'm aware, I don't use it anymore really for videos. However my confusion still exists. The Blender Foundation Open-Movie projects have all been 100% Blender except the audio design. Modeling, Animation, Rendering, Compositing, Sequencing, etc, all done in Blender. If the Blender Foundation themselves is using the sequencer for such, why would they not spend time optimizing it. they stated in the past that the Open-Projects are to use Blender for a real-world project, specifically to see what parts of it need to be further developed or added to. So why is is still so slow, idk.

@cegaton um, the page for the free version of Resolve says 1 TB disk spare required, 16 GB memory recommended 8 GB minimum, i7 recommended. Looks like a good program, but that's even pushing higher-end computers.

@D3_JMultiply I'm not interested in it being closed... I'm interested in it being answered ;-) I've used the VSE a lot, too. And especially because the Blender movies have used it, I suspect that there's a setting or something that needs to be changed. If it WERE this slow simply because of a bug, they WOULD have fixed it. Since they HAVEN'T I think it's reasonable to conclude that it's a UI/User issue, rather than a software issue.

@Matt Then I'm unsure, I have literally turned off and on essentially every single option in blender, including ones you can only change through the console or python, and it still has issues. Although, what I will say is that there's a chance that it may be related to file formats. Using Intermediate formats or distribution formats. In Intermediate formats (which are designed for editing) it uses intra-frame compression instead of inter-frame compression, allowing each frame to be obtained selectively from the file, instead of being calculated based on other frames, which speeds up gathering.

Although at the same time, the issue with distribution formats occurs mainly when dealing with changing position randomly, and less when exporting. Distribution formats are made to be compressed, but fast to read when frames are being read in sequence, being played back. And in rendering, it should be able to work the same, only instead of playing the frame back, exporting it to a file. But if Blender was designed to work with Intermediate file formats, then depending on implementation, delivery formats (like MPEG-4 formats) may suffer in performance. I'll check into this theory.

I've not had any performance trouble with intermediate formats, so I doubt that's the cause of your trouble :-/ But it's worth looking into. Any chance you could share your blender file and source video? Or a representative sample of your source video?

No, I mean performance issues from NOT using intermediate formats. for example I'm using a .ts file (Transport Stream) which is an H.264 container and thus uses inter-frame compression, and is not optimized to be able to pick a frame out from anywhere in the file. Intermediate formats on the other hand only use intra-frame compression and you can lookup a specific frame without needing to calculate other frames first.

I had a lot of trouble converting a game recorded movie in the VSE and ended up texturing a plane with the movie and using the camera view to "film" it again at my preferred 25 fps, BUT - rendering it with the OpenGL render.  It worked and played through whilst rewriting at pretty much normal speed.  The output was AVI as I recall and was converted to mp4 externally for a superior result.

Interesting Edgel3D, may have to check that out, if that's the case, then they're doing something strange with the VSE, if the 3D render can go faster than just a flat image rendering. Either way, this is a bit old, but thanks for the info.

have you tried to create proxy files for the videos that you're editing. I found that helps tremendously. The playback is at the correct frame rate. https://blender.stackexchange.com/questions/32203/how-do-i-use-proxies-in-the-vse-correctly

This has been answered many times and covers a vast number of details. Codec, nature of frame layout, scaling, etc. all contribute to the decoding speed. It isn't as simple as suggesting that all I framed encodes would be fine.

@troy_s this question was posted over 2 years ago, before having posted this I searched and at that time there were not other questions on this topic that had been asked. If you re-read my replies to comments someone suggested a few related questions, none of which actually were experiencing the same issue I was.

Gotcha. I should date check on the necromancers. My bad. Apologies. Hopefully at some point the VSE can be made fully offline and will dump all but two or three codecs to support.

Keep UI

render with "Keep UI" option in the Render properties panel under Display
(Just don't let blender display the rendering process in any window.) That was a noticeable speed up for me.

Multicore rendering

use one of the available scripts for multi-core rendering. Basically a script that opens as many instances of Blender as you have cpu cores or as many as you specify.
(Blender use for VSE render only one core of CPU by default. So even with a two core processor you get only half the render time. If you have an 8core CPU it would be great speed boost for you.)

Parallel Render - Addon, simple to use, but it generates separate movie files - one for each blender instance (that runs on each core separately).
After download, installation, enable ... you run this script with SPACEBAR search, type "parallel ..."
￼
video_editor_render_script - A python script whit it you need to arrange a few things first, but then it's a ONE-CLICK option with one animation file.
(Namely -download also ffmpeg and specify paths to blender and to ffmpeg in the script. Just follow instructions. In general it also generates separate files for each core first, but than use ffmpeg to merge them in one file.)

Try creating a proxy to reduce the load on your system.
If that doesn't work, there isn't much more you can do. Blender was not designed for video editing, it was an afterthought. Therefore it lacks certain things (like fast scrubbing through clips) that other software packages have (Vegas, Premiere, FCPX, etc).
I'm probably not explaining this very well, but what I'm trying to say is that Blender was designed as a 3D modelling and animation application, not a video NLE. Therefore it's performance in that department is severely lacking. I tried editing gaming footage in Blender and the VSE was just so painfully slow even on a high end system. It was a real shame.

You can't do a straight comparison of a game to a Blender render,
because a lot of the procedures that Blender does,
have already been done before you get your game.
Essentially the game has had textures pre-baked with bump-mapping,
normals, levels-of-detail to reduce polygon count in the distance...
The game has optimized framerate by doing all those steps beforehand.

This is an older question and you misunderstood. I know games do lots of stuff beforehand, but what I'm stating is that A game has to load more textures into memory, has to physically render 3D geometry, perform shading, handle inputs, etc. All the blender sequencer is doing during editing a video vile is reading in an array of bytes as pixels and outputting an array of pixels, and in my case wasn't even performing any operation on them other than discarding the frames I cut out. The point is that what a game does is many times more intensive, and yet it still outputs more.

I would understand Blender being slow is I was adding effects or rendering 3D geometry onto the sequencer, but I'm not, Blender is simply not optimized, considering pretty much any video editor can output frames literally tens of times faster, Blender is running some routine that it doesn't need to for what I've given it to process, that's an inefficiency. Last of all, I was never comparing the game output to the video editing output, I'm saying the recording software I use can read the screen and output at 30 fps, but Blender, doing less work, can't even get 10 frames outputted per second.


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2.79: Only some grass(Hair) particles showing up in render?
I am making a sword in stone thing and when I got to the grass, everything looked fine. However, when I clicked render, only some of the grass would show up

Any help would be appreciated

Can you provide a file with this particle system? You can use this service https://blend-exchange.giantcowfilms.com/

@Crantisz The file is too large apparently

Remove all data except ground plane

@Crantisz It is done. I has to lower the particle count. It should be 100000

You have child simplification, turn it off.

Thanks for this, why is this option on by default?


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Add a Texture to an Object using Python and Blender 2.8
i have trouble to get a script working within Blender 2.8. The following function work perfectly for me in Blender 2.79, but not in 2.8.
def CreateMaterialFromImage(matName, imgPath):
    '''Creates and returns a material from an Image'''
    realpath = os.path.expanduser(imgPath)
    try:
        img = bpy.data.images.load(realpath)
    except:
        raise NameError("Cannot load image %s" % realpath)

    # Create image texture from image
    cTex = bpy.data.textures.new(matName, type='IMAGE')
    cTex.image = img

    # Create material
    mat = bpy.data.materials.new(matName)

    # Add texture slot for color texture
    mtex = mat.texture_slots.add()
    mtex.texture = cTex
    mtex.texture_coords = 'UV'
    mtex.use_map_color_diffuse = True
    mtex.use_map_color_emission = True
    mtex.emission_color_factor = 0.5
    mtex.use_map_density = True
    mtex.mapping = 'FLAT'
    return mat

It seems to be that the material.texture_slots were removed.
Under following Link https://lists.blender.org/pipermail/bf-blender-cvs/2018-April/106620.html i found the note:

Texture slots for materials, lamps and world were removed. They remain   for brushes, particles and freestyle linestyles.

So my question is where do i find this property now or how could i change my code to get things done?
Thanks for your help!
EDIT:
https://en.blender.org/index.php/Dev:2.8/Source/Python/UpdatingScripts
This seems to be an interesting link for people run in to issues by updating their scripts to 2.8. Unfortunately there is no solution for my problem listed, yet.

A little correction: It should be ValueError instead of NameError, name error is for variable not found by name. eg. didn't assign it before access the variable.

I've been able to do this in blender 2.80 as follows:
mat = bpy.data.materials.new(name=name)
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
texImage = mat.node_tree.nodes.new('ShaderNodeTexImage')
texImage.image = bpy.data.images.load("C:\\path\\to\\im.jpg")
mat.node_tree.links.new(bsdf.inputs['Base Color'], texImage.outputs['Color'])

# Assign it to object
if ob.data.materials:
    ob.data.materials[0] = mat
else:
    ob.data.materials.append(mat)

I tried this and the texture worked, but it does not show up under properties Texture button. Is there any way to get it added to that?


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I-beam pointer background color inversion
The background color of the I-beam cursor inverted as follows (only in Blender):

Seems that something got toggled…
N.B. Loading the factory settings couldn't solve the problem.
Specs: blender 2.79b - f4dc9f9 // MacOS 10.13.6
Thanks in advance for your suggestions!
Following: User Preferences > Themes

Extra:

try File -> Load Factory Settings

Already tried without results (question updated)

I'm on MacOS 10.13.6

I found a workaround solution here: https://developer.blender.org/T53648
posted by Robert Clark on May 19 2018.
In the macOS System Preferences > Accesibility > Display > Cursors size:
…enlarge the cursor size for a tiny bit, and the bug disapears from the Blender interface.
Following the duscission on developer.blender.org, it seems that the problem is related to macOS and not to Blender.

It should be this setting, in the "user interface" section:

The setting works fine. But when passing with the cursor over text fields, the colors are inverted. (See last image)


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Find object instances with python
When using geometry nodes I can see my object has instances

How can I access position, rotation etc of all of them through python?

from bpy import context as C
dg = C.evaluated_depsgraph_get()
ev = C.object.evaluated_get(dg)
instances = (i for i in dg.object_instances if i.instance_object == ev)

for i in instances:
    location, rotation_quat, scale = i.matrix_world.decompose()
    rotation_euler = rotation_quat.to_euler()
    print(f"{location=}\n{rotation_quat=}\n{rotation_euler=}\n{scale=}\n\n")

This should list those properties of instances of the active object.


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How to subtract one mesh from another but leaving holes without adding any new faces
I have a cylinder and I subtract a cube from it. The result looks as follows

However, it adds this extra face in the center. I want to get rid of that face and have a hollow object instead. I am using Mesh Boolean in geometry nodes.

that's how booleans work. If you want to delete that face, you have to "delete" in manually with "delete geometry" (type: face)

As @Chris has already pointed out, you would have to remove the added face afterwards.
You can do this by marking the faces of the cube with Capture Attribute before. This marking remains after Mesh Boolean on the resulting mesh, so you can remove this face directly with Delete Geometry.


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Use #frame driver from python API
I material nodes it is possible to use #frame as value in Value node. But when I try to do it from python API
bpy.data.node_groups['XXX'].nodes['Value'].outputs['Value'].default_value = '#frame'

I get
Traceback (most recent call last):
  File "<blender_console>", line 1, in <module>
TypeError: bpy_struct: item.attr = val: NodeSocketFloat.default_value expected a float type, not str

How can I make this work with python?

d = bpy.data.node_groups['WorldRandPerFrame'].nodes['Value'].outputs['Value'].driver_add('default_value')
d.driver.expression = 'frame'


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Custom engine in material output target
I have copied the source code of Cycles engine (which is just an addon)
https://projects.blender.org/blender/blender/src/branch/main/intern/cycles/blender/addon
renamed it to "Mask" (and all functions variables were renamed accordingly) and made by own engine which works just fine. I can set Render Engine to Mask in the settigns and I can render the image properly.
Unfortunately my engine does not show up among targets in the Material Output node

Could somebody point me to the functions responsible for registering my engine in such a way that it will show up in Material Output target?


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camera coverage simulation
I am trying to create a camera coverage simulation where I will put multiple cameras inside a room with some objects to block the coverage of some cameras. Now, My job is to change the number and position of cameras such that the room is under full coverage of the cameras I have placed in that room setting.
My initial thoughts were, to fill all the empty space in the room with transparent small voxels and count all the voxels that are within the view of the cameras. How can I fill all the empty space of a room with transparent curve voxels and count the voxels that are in the coverage of the camera?

i would try a python script and raycast from the cameras. Then you know what camera will hit which voxels.

I searched over google but couldn't find any ray cast tutorial for blender. If you know any online references to the tutorial for the raycast, It would be really helpful.

maybe this helps you? https://blender.stackexchange.com/questions/115285/how-to-do-a-ray-cast-from-camera-originposition-to-object-in-scene-in-such-a-w

Thank you for the suggestions.


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how to get pixel coordinates from position pass?
I'm trying to get pixel coordinates from position pass, namely the world coordinate. Currently my solution is to render with position pass as OpenEXR output and get camera intrinsic and external matrix with python script. Then with the projection matrix, Zc[x, y, 1]^T = M(R[X_w, Y_w, Z_w]^T + T), it should be able to get [x, y] (pixel coordinates) from world coordinates (X_w, Y_w, Z_w). The code for parsing position pass OpenEXR and getting intrinsic and external matrix are as below.
import numpy as np
import Imath
import OpenEXR
import array

def parseBlenderExr(exr_path, h, w, exr_type='flow'):
    file = OpenEXR.InputFile(exr_path)
    FLOAT = Imath.PixelType(Imath.PixelType.FLOAT)
    if exr_type == 'flow':
        flow_bwd, flow_fwd = np.zeros((h, w, 2)), None
        (R,G) = [array.array('f', file.channel(Chan, FLOAT)).tolist() for Chan in ("R", "G") ]
        flow_bwd[:,:,0] = np.array(R).reshape(h,w)
        flow_bwd[:,:,1] = -np.array(G).reshape(h,w)
        if 'A' in file.header()['channels']:
            (B,A) = [array.array('f', file.channel(Chan, FLOAT)).tolist() for Chan in ("B","A") ]
            flow_fwd = np.zeros((h, w, 2))
            flow_fwd[:,:,0] = -np.array(B).reshape(h, w)
            flow_fwd[:,:,1] = np.array(A).reshape(h, w)

        return flow_bwd, flow_fwd
    elif exr_type == 'depth':
        depth = np.zeros((h, w))
        R = array.array('f', file.channel('R', FLOAT)).tolist()
        depth = np.array(R).reshape(h,w)
        return depth
    elif exr_type in ['position', 'segment']:
        target = np.zeros((h, w, 3))
        (R,G,B) = [array.array('f', file.channel(Chan, FLOAT)).tolist() for Chan in ("R", "G", "B") ]
        target[:,:,0] = np.array(R).reshape(h,w)
        target[:,:,1] = np.array(G).reshape(h,w)
        target[:,:,2] = np.array(B).reshape(h,w)
        return target
    else:
        raise NotImplementedError()

import numpy as np
import bpy
import os

workpath = "xxx"
external_matrix = bpy.data.objects['Camera'].matrix_world
np.save(os.path.join(workpath, "external_matrix.npy"), external_matrix)

scene = bpy.context.scene

scale = scene.render.resolution_percentage / 100
width = scene.render.resolution_x * scale # px
height = scene.render.resolution_y * scale # px

camdata = scene.camera.data
aspect_ratio = width / height
intrinsic_matrix = np.zeros((3,3), dtype=np.float32)
intrinsic_matrix[0][0] = width / 2 / np.tan(camdata.angle / 2)
intrinsic_matrix[1][1] = height / 2. / np.tan(camdata.angle / 2) * aspect_ratio
intrinsic_matrix[0][2] = width / 2.
intrinsic_matrix[1][2] = height / 2.
intrinsic_matrix[2][2] = 1.
intrinsic_matrix.transpose()
np.save(os.path.join(workpath, "intrinsic_matrix.npy"), intrinsic_matrix)

However, I found this solution not work currently even with the default "general" scene. Below is a small test. The pixel coordinate of vertex at approximately [1, -1, 1] turns to be completely wrong! Am I doing something wrong?

Oops, I found that the problem is the external_matrix got from bpy.data.objects['Camera'].matrix_world should be inverted before passing to projection equation. And this should avoid the problem above.


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Shrinkwraps Not Following Head - Pupil Shrinkwrap Not Staying On Eyes When Rotated
This past week I've learned (sort of) how to set up an eye rig for non-spherical eyes using this incredible advice: pupil constrained to a surface

Basically, I have the Eye object.
I have an empty object located inside the eye.
I have the pupil geometry parented to the empty object.

The Pupil has a Shrinkwrap Modifier applied, with the Eye as the target, giving the result in #1 in the picture.
The Empty object inside the eye has been given a Shrinkwrap Constraint, so it moves along the surface of the Eye. The Pupil object is parented to the Empty object with Keep Offset applied as the parent type, so the pupil doesn't deform as the pupil rotates around the eye.
The Empty object has a Track To Constraint applied to it, with a bone as the Target, see #2 in the picture.
When I rotate the head back, it looks like #3 and #4 in the picture.
I've tried parenting the pupil mesh to keep offset with the eye, parenting the empty to keep offset with the eye, and other random stuff that I can't exactly remember (because I wake up at 4:00AM to do this stuff before I go to work...).
What are your ideas and solutions?
If I'm going about it all wrong (this will eventually be going into Unity, so Lattice deformers are out of question, as Unity doesn't support Lattice deformation) then I'm willing to try a new approach. But right now, I can't turn or move the head from the default position without the eyes screwing up. If it stayed in this pose, it would work fine...

and here is the texture file

You mention that Unity doesn't support lattice deforms.  Does it support shrinkwrap?

@Nathan as far as I'm aware now, shrinkwrap is something that would have to be applied before it could be transferred over to Unity. I'm pretty sure any modifier has to be applied before it can be taken into Unity.
However, for this problem in particular, where I wanted to be able to animate the pupils, I think the best thing to do would be to animate the UVs or something. I never came back to this, and animated the character without eye animation. But it looks as if that would be the best go-to. No idea how to do it yet though.

Then I'm afraid I don't see the advantage in shrinkwrap over lattice-- both would have to be written to the mesh, or to a shapekey (I believe Unity calls them blendshapes.)

Yeah, I agree. I've learned a lot since then (including UV layouts, this is hideous lol)

Here is the Link to explain what I would change

These are the primary things I felt I would change if this were my own.

I would use an Empty for the focal point (instead of a bone) and parent it to the armature.
I would get rid of the two empties at each pupil.
I would tell each pupil to track (constraint) to the "NEW" focal point empty.
I would tell each pupil to pivot (constraint) to the "Head" bone.
Here is the result of doing these four things.

Thank you for your time and incredible solution. I'm at work right now so I can't get in Blender yet, but the changes sound reasonable to me! As long as the head is rotated in whatever direction and the pupils still follow the Target properly in all those directions the head is faced, I'm incredibly satisfied.
I'll take a look at it when I get home - can't wait. Many thanks again!

Wow it works! It's not flying everywhere now. But there are a couple problems with the pupil rotation... any way you know of around this?
https://media.giphy.com/media/3o7TKJqDiurP5aI9B6/giphy.gif

You could introduce two more empties that are parented to the main focal one, and have each pupil point to the corresponding one to each one of those. If the rotation seems off, you could rotate the main one enough to straighten it out. -Hope that helps

I'll give that a go.

Well having the extra eye control is nice; having each pupil look at their own empty, both pupil empties parented to the main one. Thanks for that tip. Also, rotating the empty in the x-axis, making it face more towards the head when it's lifted up and then moved side to side helps keep the pupils move in sync, so that's nice. Thanks.
I've fiddled with it a bit and still can't seem to fix that snapping that happens right when the eyes move past almost half-way up the eye. Don't suppose you have an idea of what's causing that? I can't seem to figure it out...

http://giphy.com/gifs/3oz8xt1h2RoY8HlJ16

Just curious, try rotating the Main Empty (the one you are moving) along the Z-Axis to aim at the centriod of the head (25°-45°), does that seem to solve it?

No, no difference, unfortunately.

By changing the "Pivot When" value, I get different jumping results. By changing it to "Always", it works!
... except for one thing...
https://media.giphy.com/media/3oz8xCTAcn4EL9DoWs/giphy.gif

I've tried rotating it too when it gets to the point where it distorts. I wonder if it as something to do with the pivot loction/origin https://media.giphy.com/media/l3vR1EZTtxX3dQu64/giphy.gif

Ah hah! The geometry for the shrinkwrap os moving all over the place... How can this be solved? Simply origin, right...? Where would be the best spot for it? In the GIF, I'm simply moving the Empty only in the Z-Axis.
https://media.giphy.com/media/3oz8xJnAZyJHsGD4jK/giphy.gif

Here's my current .blend file:

Let me know if this works, and I'll modify my answer to fit: Updated Model. I turned your pivot constraints off on the pupils, and Re-Adjusted your origins for both the eyes and the pupils. This seemed to solve a whole lot, because the rotation pivot becomes natural (not constrained). This might not be completely perfect, because the eyes are oblong (if they were true spheres a single point works well), but it seems to react a lot better anyhow.

That's fantastic. Works much better and cleaner. Yeah, it's not perfect at the top of the eye but I might be able to mess about with the pivot points.
Oh, except when I rotate the head back, we have the original problem again of the pupils not following the head... d'oh!

Unfortunately, I still have to call this unsolved because we ended up with the original problem again. I really appreciate the time and effort you gave previously. :)


text:
"F" Button in Shape Key Editor Not Showing Up - Why Not?
I'm trying to export a model with armature and shape key animations. I've been following this tutorial:
https://www.youtube.com/watch?v=wvjwTnS6vhA
This process works fine for the beak of my character, but not for the eye lids and pupils. The pupils have shape keys to make the character look left and right.

Now I wonder if it's because the beak only has one shape key and the eyes and eyelids have multiple. But so far, the beak is the only one ready to go.
I just need the animations to export into Unity with the shapekeys. Here's my .blend file:

The "F" button is to tell Blender to save a data block even if it has no user, so it appears only when... you have a data block!

In your picture, you have this situation for that eye:

the " + new " button means, there's no data block, and you can add one (an action in that case). Then, the "F" button will appear.
edit
I think that eye has something different than the other...

selecting that green NLA editor stripe, and using TAB it expands, and the " + add " becomes usable, but acts weirdly, at least...

I'm not an expert though, and can't understand how to fix it. But maybe you know what happened to that strip?

Can you get it to show up on my file? I can't :/ even after pressing "+ New"

Not really but I spotted something strange in the NLA strips... see the edited answer... maybe someone can spot what's wrong here...

Hm. I really wish I understood this better. The long way around would be to recreate the pupils and eyelids and animate them. Really don't want to have to do that, especially for the eyelids. Shape keying those was a pain.
Help anyone? Much appreciated.
:S

Did you try unlocking the stashed nla row?

authors: سجاد فرخ حیاتی


text:
Why is this bone not keyfaming or animating when keyframed?
I've been animating a character and everything's been fine until I tried to move the "Belly" bone's location. At first, I wouldn't get any errors, and when keyframed, the belly wouldn't move. It would just stay in the last position I moved it in. Rotation's fine, and every other bone is fine, but this one's not.
Even in the properties, the rotation and scale values were yellow, showing a keyframe, but I couldn't keyframe the location values - they just stayed green.
Then I tried fixing it and I think I made it worse, not sure what I did. Now it won't let me keyframe it at all - location OR rotation.
I need to be able to animate at least the belly's rotation and location.
Here is my .blend file -

As the error message hints, your animation channels are locked:

You need to click the padlock icon next to the bone name in the Dopesheet Editor to unlock them all. You probably just clicked it by accident. This solves being able to insert new keyframes, but the bone still doesn't move when animated. This is because the location channels are also muted:

Locking protects the animation channels from being edited (inserting/deleting keyframes) and muting temporarily disables them (hides their effects).

Oh my gosh -facepalm- thank you for going to the effort of figuring that out. Couldn't for the life of me figure it out. I'm at work right now so I can't access the file to double check, but with all of that unlocked, are you able to animated its location now? I may have clicked that in the process of (trying) to figure out why it wouldn't animate.

@JosephClarkAbrahamBurgan You're right, that didn't fully solve it. I've found an additional step that needs to be done. I'll edit the answer.

@JosephClarkAbrahamBurgan This should work now.

Interesting, I didn't know about the muting option. Must have clicked those by mistake and not noticed it. Thank you.

Make sure to keyframe the frozen original moment twice, then after a few seconds of frames, make a movement.
To keyframe type i  and select Loc, Rot, Scale.


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Cant get proper obj copies from alembic frames
I am currently working on vertex animation texture generation inside blender and I got pretty far, I specifically was working on remeshing water simulations to always use constant amount of vertices/polygons.
But now I wanted to debug it with a simple Icosphere rolling down from a slope,
The problem is Blender refuses to make correct copies and get the correct vertex position data even tho it fully works for imported alembic files of water drops but not a simple rigid body simulation?
They both are mesh cash animated objects inside blender and the script expects them to be
relevant function from my script:
https://pastebin.com/cc96nB5j

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, add code snippets, along with thoroughly explaining the problem in text form so it can be indexed and searched for thus helping future visitors with similar issues.


text:
Is there a way to make denoising work in the Cycles viewport?
I saw this in other renderers, such as the Radeon ProRender or V-Ray and was wondering if there's an Add-on or Build for Blender to work around the limitations of Cycles' Denoiser.

No, there is not. From the Official Manual Denoising uses render tile information from the engine to make the necessary calculations for the image processing algorithm.

Denoising filters the resulting image using information (known as
  feature passes) gathered during rendering to get rid of noise, while
  preserving visual detail as well as possible.
To use the option, enable it in the render layers tab of the
  Properties editor. On rendering, it will denoise tile by tile once all
  the surrounding tiles are finished rendering.

It is not available for progressive renders, and as such doesn't work for viewport previews, which are a form of progressive render.

Thanks. I rephrased the question so I can hopefully still get denoising for the viewport :)


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Array isn't following curve
I have set up an array modifier and a bezier curve which the array is following. My spheres aligned themselves in a straight line for the length of the curve, however they are not following the curve exactly.

This is not a duplicate. I have followed every answer of the already
posted questions and none of them worked.

yes please share your file here: https://blend-exchange.giantcowfilms.com/

The file doesn't show up in the questions although it says it uploaded.

I guess you have to edit your question and copy paste the link

Now it's there... I thought it would upload automatically. Guess I should should pay more attention.

Fit to curve in the Array modifier is only used to get the length correct. If you want the array to curve with the curve then you need to add an additional Curve Modifier.

You need to remove the Radius check from Curve deform. Then just adding a Curve modifier and setting the curve will make your array follow it.

Add a Curve modifier and, in this modifier, choose the Bezier Curve as the Object
You've changed the radius of the curve vertices, so select the curve, enter in Edit mode, select all, open the 3D view properties panel on the right of the 3d view (press N), and in Transform choose a Mean Radius of 1


text:
What is a smoothness map?
Is a smoothness map the same thing as a roughness map?
For example:

Smoothness is the opposite of roughness. If you have a smoothness map you can use the "Invert" node to plug it into a roughness input. You can find it under (shift+ a) Add -> Color -> Invert.
For example:


text:
Topology improvements?
I am making a guitar, and I was wondering if there was any advice you have on making the topology for this?  I did a lot of things manually, like extruding and filling in faces on the front view.. but it takes awhile.  I started off with a circle, then starting extruding off of that, because there was a circly shape in it.  Is there a simple way to go about things, or does it just get time consuming mapping this all out?
Is there any mistakes, or have any advice on the given topology before I proceed? Or is it fine the way it is?
I'm fairly new to blender, and am just trying to learn things the correct way!  Thanks!

And after tinkering around a little bit I came up with this.

Here is a 3rd attempt at it a little differently.

Your attempts are not bad at all. I really like the edgeflow in the second attempt. My only concern is the density of polygons in the middle of the model.
Personally I would do something like this:

When modelling, as a rule of thumb, always try to keep Your faces as square as possible and try to keep them all even sized.
This makes it easier to control the subsurface modifier, makes the model more flexible in animations, and makes it easier to prevent texture stretching.
I started with a face, went to edit mode, and edge select, extruded E the faces in top orthographic view. Then I rearranged the vertices, using G in the same view. 3-4 minutes of work in total.
But it really comes down to what you are going to use Your model for. High poly model, then I would try to tweak Your second attempt in order to even out the polygon size.

While I didn't cast the DV, maybe expand on why faces should be square and even sized.

Thanks! I'll try to attempt to use the 2nd model and try to get things squared up.. I suppose just I ball them into more square shapes?  From what I understand, the more square they are they better they show up rendered?

This makes it easier to control the subsurface modifier, makes the model more flexible in animations, and makes it easier to prevent texture stretching. However I almost always stray from this path when I have to define the edges. As I like to bevel the edges in the modelling proces... There are a thousand ways to do this, and this is just what I tend to do


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Issue with "non-planar" edge loop
I am in the process of modeling the refit USS Enterprise. I have reached an impasse at the bridge area. It's difficult to explain, but essentially I have an edge loop that needs to be filled in and it's not planar, if that makes sense. I'm not sure what the nomenclature for that is.  Anyways, I tried using grid fill to no avail so I decided to fill it in manually. I feel like my topology could be better though, and would be grateful for any feedback.

Hello and welcome to the site! I honestly struggle to understand the current shape of your mesh. In addition to the two side views, can you also attach a view not parallel to any axis?

I have attached two more images

Thanks. I'm not a skilled hard surface modeller so I won't attempt to answer your question, but the added information might help other users.


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Nothing shows when rendering
As the tittle says, I've tried to render my model for quite a long time.
I read a post here but I couldn't solve anything, this is my current configuration for lamp/camera
I have already tried every solution in threads here, doesnt solve anything, I've actived nodes but still doesnt show up.
I dunno if it can be because the size of the camera and the lamp (The object is like 40cmx25cmx7,5cm and the lamp/camera is default size)

EDIT: I've tried by recommendation of another user to delete and add another camera, the problem still persists

Also see https://blender.stackexchange.com/questions/53632/render-result-is-completely-blank/

Lamp and Layout.000 are restricted from rendering (see the Outliner in the top right box). Could it be the problem? This is one of the things explained in the links @DuarteFarrajotaRamos provided

No, the lamp and the "Layout.000" being restricted from rendering are not the problem, I already tested that.

Turn on Display Limits, and make sure that your object inside clipping zone:

All objects outside will not shown.

Try setting your camera Focal Length to a number in the range 20mm — 105mm and see if that helps.
Focal length = 1m is a very exaggerated setting and you've probably set it by mistake

Edit:
also, your clipping Start and End settings are weird. Start must be smaller than End, and End should be much larger: try 1 meter!

To summarise: it looks like you have messed up with your camera settings. Creating a new camera and deleting the existing one should fix your problems.

No, doesnt work.

Please see the edit: does it work now?

No, sorry, I added a new camera, but only shows something when is right in the object (inside it) when I try to move it around doesnt show anything, or just a tiny part, but when I try to move the camera with ctr+alt+numpad0 I still cant see the object EDIT: Gonna edit the main post now with 2 new pictures

just try: blender allows to set "Start" bigger than "End". But yes result can be fun


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Blender not extruding planes properly
For some reason whenever I extrude a plane face and try to delete the newly made face it doesn't actually delete. The extruded face deletes as expected when using a cube, but not a plane.
Video showing what I mean:
https://i.sstatic.net/xMfTg.jpg
You see when I extrude the face on the cube, shrink it, and then delete it the face actually disappears. This is normal. However, when extrude the face of a place, shrink it, and then delete it the face does disappear, however, the original plane face doesn't as if it wasn't effected by the extruding. It's as if Blender is duplicating the plane before extruding it. So when I delete the face expecting to see a hole where the face use to be I instead just see the plane I was originally started with.
I've been using blender for a while now, however, I don't remember the extrusion behaving this way for planes. Any ideas?

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.

Understood. Sorry.

Spotted! :) It does seem that if E face-extrusion finds itself asked to extrude a region whose perimeter is entirely made up of boundary edges, it will leave the original geometry in place. Otherwise, it won't.
That behaviour is so desirable, in the normal course of modelling, for the creation of manifold meshes starting from bounded regions, that personally I hadn't even noticed it. Despite being strictly inconsistent, it looks like an 'executive decision', rather than a bug.
For single faces, to obtain a bottomless extrusion, you have AltE > 'Individual'.
For multi-face regions, you have I inset, by 0 'Width' if wanted, and an adjustable 'Depth'.

I agree. Using E > S means that the original plane is effectively being duplicated and then scaled inwards as you can see by the z-fighting in the video. Deleting the scaled  face leaves the original in place.

Ah, thanks! I appreciate the answers.


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Anime ground break/shatter effect
I've been messing around in Blender trying to recreate this ground breaking effect:

I've tried messing with shaders and displacement. I tried finding a way in geometry nodes.
I think im tackling the problem in a wrong way. Currently stuck with no idea on how to do it.
Any help/ideas? Thanks in advance!

Hi, i know you are new here, but you should focus on one problem, not on a whole animation. So where are you stuck at? You can ask as many questions as you want here, but you shouldn't ask on a whole animation...but just one part.

Its not the whole animation, its just that shatter effect. You see how the ground break? That is the only thing im trying to achieve

What about using cell fracture?

Cell fracture? I have not heard of that! Got a good resource for it?

It’s an add-on delivered with Blender. Just enable it

Thank you! I'll give it a try!

Jup! With some proper animation timing etc i can (mostly) get that effect! Thank you!!!

You are welcome

https://blender.stackexchange.com/questions/209264/can-i-make-a-sim-where-water-breaks-a-glass-window/ https://blender.stackexchange.com/questions/6686/how-do-i-make-an-object-bend-or-break-if-hit-with-sufficient-force/


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I can't find the Hair option in my 'Render Properties'
I'm trying to follow a tutorial and they enable the 'Hair Shape type Strip' in their 'Render Properties'. I can't find it in mine. I've tried looking around online too but I can't find an answer. Has it been moved somewhere else? or removed entirely?
I'm on Blender 3.2.1 btw

Blender 3.3 introduces a new Curves object type that will supersede the hair particle system in the future.
It looks like a few hair related things have already been renamed in Blender 3.2.
The Hair section is now called Curves. It's below the Performance section in your screenshot, well, in the middle. Just expand it to see the familiar options.
Furthermore, the Hair Info node in the Shader Editor is now called Cuves Info.

Yoooooo found it! Thank you very much!


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Why does my project not appear in the final render after I render it?
So I’m working on this project, and I’ve tried to render it multiple times, turn down the samples, turned down the lights paths, and just tweaked some settings to make it render faster. And when I go to render it, neither the render view or the final render image shows up. And I could see the render view before I restarted my laptop but now I can’t even see that.

without seeing any of your settings your question is way to vague. Since you are new here it might be the best if you provide your blend file.

https://blender.stackexchange.com/questions/67490/why-does-my-object-not-show-up


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Preserve vertices within a certain distance from another mesh
I have two meshes. Mesh A (cube) and Mesh B (monkey). I would like to only retain the vertices of mesh A that are within a certain distance from mesh B using python.
Like in the example picture below, the monkey head and the cube would be right next to each other and I would like to select only the vertices of the cube that are within a certain (small) distance from the monkey head. I moved the monkey head in the image below for illustration purposes and in my situation these two meshes would be right next to each other. From there I would use select inverse and delete the inverse selection in python to only preserve the selected faces/vertices seen in the image below.
The image below is a simplified version for illustration purposes of what the issue is that I am trying to solve. The meshes I am working with are more complex. I am looking forward to any creative solutions or ideas!

So the "Cube Object" has a boolean difference on it that has subtracted the "Monkey" object from it and you want to delete everything except the verts that were cut into the Cube from the boolean?

Yes, I created this example for illustrative purposes. In reality I have two more complex meshes that run partly along each other and I would like to retain only the parts of one of the meshes that are close to the other. Some parts of the mesh (the backside of the cube) are far away from the other mesh (the monkey) and I would like to delete the vertices corresponding to this part that is not touching the monkey face.


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File Output node name
Is it possible to use wildcards when exporting with the File Output Node? I use a DAW called Reaper that have that feature -to export with all possible variations.
So what I'd like to be able to write in the  (dollarSign)sceneName(dollarSign)dateTime.png... ah, you get it.
So it dosen't overwrite the same Image001 over and over again and so I can keep all renders. Is this possible? Some Addon?
Or is it possible to modify the current File Output Node? What would be even better perhaps?


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Could someone find any logic in the rigid body world and rigid body constraints behavior?
I have a scene where I'm trying to find a logic for better understanding of rigid body world and rigid body constraints regularity.

The setup seems work as I expected, but when I move the "Vert" object to the negative X direction or to negative Z the constraint on "Empty.007" doesn't move the "Circle" object and the "Circle" doesn't fall. I guess that happens when the "Vert" object gets out of the limits of the constraint. But I'm not sure because when I try to expand the limits it doesn't help.
Also I completely don't understand why the disabling the collision of the constrained objects (by "Disable Collisions" checkbox) in "Empty.007" makes the Circle object stay still.
And as you see I made a weird "Vert" object. That's because I didn't find a working way to bind the "Circle" object to Empty by a Rigid Body Constraint. Is it even exists or I must have a manifold Rigid Body for that?

Probably that are a bugs of Blender 2.83.6. It seems like all works as expected with Blender 2.91.


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Use 3D mouse in Blender
I'm quite big on using my 3Dconnexion SpaceMouse (I use it all the time for CAD work), but using it with Blender isn't exactly plug 'n play. I can get some but not all axes of rotation to work and on the internet I can only find information that seems either outdated or somehow irrelevant. Help!
EDIT: I use Windows 10, and a wireless 3DConnexion SpaceNavigator. When I plug it in, the following 4 DOF axes work:
zoom in/out
shift left/right
shift up/down
rotate towards/away (from my perspective)
The problem is with the other 2 DOF axes: rotate sideways (from my perspective) and rotate about the object's long axis (my best description: if you model a beer bottle and rotate it about it's long axis you won't actually see something rotate, that's the axis I mean :P).
Now, according to one source (https://www.3dconnexion.com/forum/viewtopic.php?t=1497&start=30) the solution may be in: user preferences -> input -> 3D-view -> 3D-view (Global) -> NDOF Orbit/Pan/Move
but after a short attempt to make that work I concluded I didn't really understand how to do that.
Hope that helps more!
Cheers,
Caspar

Windows, Linux, Mac? What did you get to work and what links did you use?

rob, wanna get back on this?

sorry, I do not have any expertise in this area and was just hoping to kick start some one who does. If you believe it is a bug then you should report it to the devs. https://wiki.blender.org/wiki/Process/Bug_Reports

I've gotten about 3/4 of the way there on this. I can move in every axis. However, you have to hold shift to Pan. While panning, you can't orbit. It's quite frustrating, but it's better than nothing, I suppose. Do the following:
Reverse all axes and crank them up to max in the 3DConnexion software.
I have the following settings in Blender:


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Parent to vertex unwanted offset
Making an wraping dodecahedron animation. All the pentagon's movements are related with parent vertex.
It's ok on the final stage - all connects correct, but while the animation the pentagons are moving with unwanted offset one from each over:

What do you mean by 'parent vertex'? Could you describe a bit more the way the parenting is done or upload your file here http://blend-exchange.giantcowfilms.com/?

OK, thnks, uploading the file. "vertex parenting" as described here" - https://docs.blender.org/manual/de/dev/editors/3dview/object/properties/relations/parents.html

OK... to me, parenting like that and using shape keys is far from the simple way to do that. Mainly because shape keys wont rotate but will linearly interpolate the positions. I suggest you use armature parenting having the bones rotating from 0 to 63.44° (check that!). Note also that this parenting can be made so that all pentagons are connected in one mesh with no doubles (the flat shape, I mean)

or... far better... simply use object parenting between pentagons!

but how can I rotate i OBJECT mode along the axe I need? Same for bones! I know how to rotate in edit mode...

Ctrl+Alt+Space can be used to define custom orientations axis https://wiki.blender.org/index.php/User:Rking/Doc:2.6/Manual/3D_interaction/Transform_Control/Transform_Orientations. From that, select a pentagon's edge and define this custom orientation from it (sorry wont have time to write an answer now...)

Note that it will work with the manipulator but not with R shortcut (a bug?)

FYI, after a little test: you will have calculation rounding so that parenting at object level wont work (similar to your first attempt even if smaller). So, I think using bones on one single mesh is better

Short answer as already answered here  Wrapping geometry object animation
If you start with a face setting like this, you can rotate 72° to obtain the other faces:

Now if you set the snapping like this:

And use an empty as active element, you can place the face next to the others as you need:

Finally you obtain this:

From that you'll need (I describe this quickly as this is not the direct subject):

to join the bones,
join the faces (and remove double)
parent them with empty groups and assign the needed vertices to the corresponding groups manually

Now, as the bones are all along their local axis (along Y), you can rotate them all around X using 'individual origins':

So you can rotate them all around their local X axis, using RXX (twice X for local axis):

Last step: the dodecahedron as an angle of arcTan(2) = 63.434949°. So we need
to set a keyframe for this rotation value.


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How do I invert this timer in BGE to make it count-down?
This is from an answer I received here: timer

I suggest to avoid this method to measure time. The BGE will try to
  keep the given frame rate as much as possible, but there is no
  guaranty.
I recommend to use a timer property. It counts the seconds. I think
  that is what you really want.
Then you have several ways to show the time. I think you want to
  format it to minutes:seconds. You can use this little script
  timeToText:

 import bge
 from datetime import datetime

 textObject = bge.logic.getCurrentController().owner
 time = datetime.fromtimestamp(textObject["time"])
 textObject.text = '{:%M:%S}'.format(time)

It expects a property time to provide the seconds and should be
  applied to an text object.

You can indeed refresh the display each 60 frames. But you will not
  know when the seconds changed. Therefore I suggest to run it
  constantly.
Hint: If you want to show microseconds too, use this format:
  {:%M:%S.%f}

This works. But the timer in bge counts upwards. What if I want it to count let's say from 30 minutes downwards?
How can I "invert" the timer?
I guess I can assign the original value 30 to the property time but how do I achieve the countdown logic afterwards?

You could simply negate the time property (-1800 seconds) and parameter of datetime.fromtimestamp(-textObject["time"]):

import bge
from datetime import datetime

textObject = bge.logic.getCurrentController().owner
if textObject["time"] < 0:
    time = datetime.fromtimestamp(-textObject["time"])
    textObject.text = '{:%M:%S}'.format(time)


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Triangulated mesh to Nurbs surface conversion
I am looking for a feature/workflow/add-on for blender to convert triangulated meshes into a nurbs surfaces.
While looking on the internet for a solution I found this software that looks like it does exactly what I would like to do but I would much prefer my entire workflow to be within blender.
Any help, advice or ideas are much appreciated!
Alex


text:
Can you copy weight data to other side of mesh (Blender 3.2)?
Is it possible to mirror your weight painting AFTER already painting one side of your mesh?
My armature was paired with automatic weights and I adjusted the RIGHT side of my mesh, assuming X symmetry would automatically reflect on the opposite sides.  Evidently I assumed wrong and now only the Right side of my mesh has the correct weights while the other still has the automatic weights.
Is there a way for me to copy the weight painting of the Right side of my mesh over to the left so that the weights are consistent?  Or will I need to bite the bullet and paint the left side by hand?
Thank you for your help!

Yes, you can copy weights over quite easily, providing the mesh is truly symmetrical. All you need to do is:

Select your Left Arm's vertex group, click the little down arrow and choose "Copy Vertex Group". Now we will mirror this duplicate group to the right side.

Now select the new duplicated group, click the down arrow again and choose "Mirror vertex group".

All that's left to do is to simply rename this freshly mirrored group to be the same name as your original Right Arm vertex group-- however, since two groups can't both have the same name, you'll need to delete the original group or rename it to something else first.

By LEFT or RIGHT, I meant your character's physical LEFT or RIGHT arm in relation to their head, not screen left or right, as described in your post (which is what we see when looking in a mirror). But the principle of mirroring remains the same. :-)


text:
How to export part of a model in Blender as an STL file and keep the original scale
I made a model of a character, and I [![want to export it to parts as stl files to 3D print. But when I export some part of character, I found it size change, what should I do?

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.

https://blender.stackexchange.com/questions/192314/export-to-stl-format-in-correct-scale-inches?rq=1


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Don't see "Dimensions" in Transform (N) pannel - checked
I'm newbee here and already have some troubles with "Dimensions" panel - the thing is that I haven't it by some reason. What I did wrong?

Aaah, it's not look like a solution, but when I deleted the default cube and created new one, dimensions panel appeared

You had a lamp object selected, lights have no dimensions


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How to export vertex colors
this is a follow-up to this other question.
I now have a mesh with vertex colors applied as attribute inside the Object Data Properties.
I have tried to export this mesh into various formats, including .ply, .fbx and .gltf, which are supposedly saving vertex colors.
However if I reimport the file the vertex colors are all lost, as well the original color attribute.
So I tried to use the Geometry nodes, thinking that maybe the Vertex Color layer was not properly written into the geometry.
I added a socket of type Color to the Group Output tree and I linked the Color Attribute to it, and then I applied the transform.
The expectation is that the vertex color becomes a property of geometry itself rather than an external attribute, so removing the attribute would maintain the color of the mesh, however the information is lost.
So I'm wondering if the geometry nodes are required at all, and which one is the format that keeps vertex color (some say .obj exporter will not keep it and to use .ply, others say to use .fbx, others collada).
Thank you

What type of color attribute are you using (domain/datatype) and what version of Blender? Traditional vertex colors (Face Corner + Byte Color) will be best supported since the other kinds were only added in 3.2 and exporters haven't been updated. I believe exporting to glTF or OBJ (non-legacy) should work with all kinds if you're using 3.3/3.4 though.

That did it! I was using Vertex domain and Color data type, switching to Face Corner and Byte Color correctly exports the vertex colors! @scurest You may want to post an answer and I'll mark it as correct.

After hours of trying to solve this same issue, I think I have worked it out.
In the Attributes popup, you need to convert the Color attribute to Byte Color, and the Domain attribute to Face Corner.
EDIT: to access the attributes popup, under the +/- icons next to the Attribute > Color, click on the down arrow to access the Convert Attribute menu.


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property timer value
Coming back to this thread: countdown timer
I want to check the time property and set a new scene when it reaches 0.
What should I put in the Value box of a Property-equal sensor to check for when the timer reaches 0? I tried 0, 00:00, some other formats although I think I can't really put expressions there and none of them worked.
Maybe this textObject.text = '{:%M:%S}'.format(time) is something that I can't play with in the Value box of the Property and I need to go through python, but I wonder if there is a simple logic brick solution.
These are the logic bricks.

I found what was wrong after I printed the property.
The values of the property are float with tons of decimals, meaning it could end up to be 0.00000000002 and never reach 0.
So you can either round the number but it would round it when it gets near -0.5.
So I just changed the equal-property to be a greater-than-property and set its value to be -0.1.
So now since it is a countdown timer, when the timer reaches second 1 it sets my new scene.

As the timer property provides a float value, you need to check if the value is "equal or above zero". Since Blender 2.74 the property sensor has according modes. If you use an older version, you can use the interval mode
The value to check against is -> 0 or 0.0 it does not matter which one.

I edited the question and added an image. It does not work with either 0 or 0.0 . What could I be doing wrong?

Sorry, I was not clear in my statement. It should be "zero or above" (both conditions needs to be checked at the same time)


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How to rotate object around another with rigid body constraint in BGE?
I want to use rigid body constraint to rotate the camera around a cube accordingly to the angular velocity of the cube(all of that in the BGE).
1)Is it necessary for both objects to be rigid? For one? For none?
2)From this question I understood that what I want is a slider constraint but I want the camera to be affected by the rotation of the cube and the cube to be unaffected by anything the camera does.If it is possible how do I fill the empty boxes in the constraint and does it matter which object will "own" the constraint?
3)Any good video tutorial for that purpose(the pivot) will be appreciated.


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Why is my UV mapped texture dissapearing when I start blender game engine
All I want is to add a single texture to a plane which will display in the game engine. To do this, I

unwrap a mesh in edit mode
open UV image editor
open image... its a pgn. but ive tried with jpeg as well with no luck.
In materials, add new material and click plane
In texture, add new texture and use the Image or movie and then under Image, I select my image file.
I change the view port from solid to textured.

With this process, I can see the image projected onto the plane. I can also see it when I hit f12 to render. My problem is, that when I start the game engine, the image texture does not show on the plane. All I get is the original grey plan that I started with.
I've already tried switching to GLSL mode. Any suggestions would be greatly appreciated. I've meticulously tried all of the suggestions offered on the forums and haven't had any success. Thank you.
Here is the blend file reference

My computer's graphics card.
Display Devices
      Card name: Intel(R) G41 Express Chipset (Microsoft Corporation - WDDM 1.1)
   Manufacturer: Intel Corporation
      Chip type: Intel(R) 4 Series Express Chipset Family
       DAC type: Internal
    Device Type: Full Device
     Device Key: Enum\PCI\VEN_8086&DEV_2E32&SUBSYS_2A9D103C&REV_03
 Display Memory: 1582 MB

Dedicated Memory: 64 MB
      Shared Memory: 1518 MB
       Current Mode: 1600 x 900 (32 bit) (60Hz)

The following is the link to the .blend file I am working on.

I have downloaded and test the file which you have attached.
Pressing P does reveal the image in the game engine on my screen.
I suspect you user preferences setting were different from mine.
Now that I see your graphics card, I am suspecting it could be a hardware/software limitation. I went on the internet and search for OpenGL driver for the card. And it seems that you have to download a package to enable OpenGL support. Maybe you could read up here and download the appropriate OpenGL package for your card?
Link here https://downloadcenter.intel.com/download/20046/OpenGL-Support-Web-Link
Link to the G41 Express Chipset here https://downloadcenter.intel.com/product/81517/Graphics-Drivers-for-Intel-G41-Express-Chipset
Hope this will resolve your issue, good luck.

I have attached the link to my .blend file under my original post. Thank you.

I am using the default user preferences. Do you have any suggestions on what user preferences I might change? Perhaps my computer isn't fast enough? Thank you for your feedback.

I tried the suggested and now when I enter game mode, the image and the plane disappear completely. However in render mode, the Mario character shows correctly without the plane outline.

Dont worry about the transparency for now ... I have included that because I guess it's the final effect you may want ... since you are dealing with a transparent PNG. I can't seems to make the image disappear on my end ... so we know what needs change.

See my updated answer.


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I don't know why object has changed color

Why is the color on the area near the mouth and nose of my model more dark? I can't change it and I don't know what is it. Even when I add texture it is visible.

check to make sure your normals are correct.

From looking at your screenshot, it seems that your normals are inconsistent. To fix this,  Tab  into edit mode, then select everything by pressing A  twice,(assuming nothing is already selected in the scene) and press  Ctrl +  N to make your normals consistent.
You can usually tell if your normals have been flipped because the shading on your object will darken.


text:
Why image distorted by UV Map node is like lowres on output?
Image texture looks pixelated (like a low-res) on output in the UV Map node when using the Compositor editor even source is high-res.
Distortion of image is from UV render pass. Did I miss something in setup?

@NoviceInDisguise Huh? The OP here sounds like they don't want pixelation..

Not knowing the texture size, I would suspect that the exact same issue is being encountered.

@NoviceInDisguise I think gandalf3 is right, he seems to be asking why it is pixelated, not how to make it pixelated.  Even if that answer applies to this question (and I don't see how it does) the question isn't a duplicate.  I might suggest a close for being unclear though.

I did not realize that my voting to close as unclear what you are asking would count as a close vote for a duplicate.  Is this a bug or is that just how it works?  I don't think the question is a duplicate at all.

@PGmath Good point. And I have no idea why it would close as a duplicate when you did not vote that way . . .

@PGmath That's how it works. I don't really like it either, but I think it does this because it gives the close reason provided by the majority of close voters and a list of the close voters (regardless of close reason). BTW, I don't really see what's unclear about the question? I tried and failed to find an answer (never used the UV pass before), but perhaps I'm missing something..

@vklidu Try saving the UV pass as full floating point exr.

As pointed by @gandalf3 in a comment ... the UV pass has to be saved as full floating point EXR file format to have enough color range to translate texture without pixelation.


text:
Can I use/convert absolute normal maps in Blender?
I have a model I got from... a place (I'm not able to show the actual model). It came with normal maps, but it's an absolute normal map rather than the more typical relative normal map. IOW, rather than encoding a displacement that is added to the model's geometric normal, it encodes the exact normal. (The model isn't intended to be animated, so it can get away with this render optimization.)
Now, I could probably code something up using GLSL to render the model in texture space and output the difference between the geometric normal and the normal map value... but that's a pain.
Is there any way to turn an absolute normal map into a relative normal map using only Blender? (Obviously I'll need both the geometry and the normal map.)

For anyone that doesn't understand the problem from the description, here's a mock-up of relative and absolute normal maps of a perfectly smooth (i.e. the normal map is a no-op) tube:

(Note that this is just a mock-up using a nine stop gradient; the interpolated values won't be quite right, and may not produce unit-length normals. However, it should be "close enough" to understand the difference between normal map types.)

Yes. Blender allows you to choose what "space" a tangent map is in. The default, Tangent Space, corresponds to "relative" as in the question. There is also an Object Space option.
However, Blender's notion of the object space coordinate system may or may not be a match for the source normal map. While this can be fixed entirely within Blender using shader nodes, it's probably easier (and lossless) to convert the input normal map externally. For example, here is a Python script that swaps the red and green channels and inverts blue:
import numpy
from PIL import Image

in_name = 'in.png'  # replace as needed or get from command line
out_name = 'out.png'  # likewise

# Read original normal map
data = numpy.array(Image.open(in_name))

# Swap R and G
data[:, :, [1, 0]] = data[:, :, [0, 1]]

# Invert B
data[:, :, 2] = 255 - data[:, :, 2]

# Write result
Image.fromarray(data).save(out_name)

You may need to experiment to determine what transformations (if any) are needed for your specific case. One way to do this is to bake normals with no normal map applied and inspect the resulting color values for known points on your model. You could compare single-channel images for both your "real" normal map and Blender's baked normal map. Extract each channel of each map as a grayscale image, and save both the original and its inverse. (Be careful to use linear color space throughout.) Then, figure out which pairs go together.
Note that a good way to tell if your normal map is "correct" is to change the strength between 0 and 1 repeatedly while using material preview shading. If everything is correct, you should see minimal change in your model. If the color/light changes significantly, you have swapped and/or inverted channels.


text:
Turning line segments into flange bolts?
I find myself making various models (furniture and related things) that involve fasteners. Because these are representational (i.e. intended to serve as plans for making things in the real world, not as end products in and of themselves), I don't need a lot of quality, but it would be very helpful to have a way of representing things like screws and bolts.
Now... I could use instances and make a model of every possible fastener, but this seems like a problem that would be better addressed with parametric modelling, i.e. using geometry nodes. Besides allowing things like diameter to be entered as inputs rather than being directly modeled, this would have the additional benefit of allowing me to use line segments (curves) to represent fasteners of different lengths without having to make a separate object for each length.
Let's focus on flange bolts as these seem the most complicated, and the hard fiddly-bits are likely going to be the same for most fasteners. Fortunately, because I don't need very high visual quality (and because the threads are often hidden anyway), I don't need threads. All I want is to turn the curve segments into pipes, representing the shafts, and to add simple heads consisting of a thin cylinder and a thicker hexagonal prism. (In particular, the heads need to stick to one end of each curve segment and be oriented according to the direction of the segment. Note that the head should be "beyond" the curve point, i.e. the curve segment corresponds to the shaft without the head.)
How can I accomplish this?

Here is a crude visualization of what I want as the end result. (This is poorly/unrealistically proportioned because I was just whipping up something as fast as possible. Geometry nodes would of course allow all of the dimensions to be easily tweaked.)

Check out the built-in addon Bolt Factory. I think everything you need can be found there most likely.

@Jakemoyo, unless I am missing something, that is exactly opposite what I want to do. Yes, I can use BF to create a highly detailed model of an exact bolt. However, it's impossible (okay, very difficult) to modify that bolt, and particularly it doesn't turn line segments into ("good enough") bolts using geometry nodes that also let me dynamically.

Okay, I confess, this was mainly an exercise in transferring knowledge to myself, but I also hope someone else finds it useful.
TL;DR
This is what I came up with after some refinements:

And here is a preview:

(If this was in edit mode, you'd see curve endpoints at the start and end of each of the shafts. Changing the bolt positions and lengths is just a matter of changing the line segments of the curve object. Head dimensions are inputs to the geometry nodes. Curved bolts are possible but discouraged. )
Explanation
The parts of the head are pretty simple; they're just Cylinders that use inputs for some of the parameters. (The flange also has a node to smooth the normals, since we don't want it to look faceted.) The slightly-tricky part is translating them so that when we use them as instances, the instance origin is the base of the head rather than the middle. (This also means the flange is aligned to the base of the head rather than having the hexagonal part sticking out both sides of the flange.) This is accomplished with a Vector Math node that multiplies the height of each cylinder by the vector {0, 0, -0.5}.
A cheeky Math node multiplies the input shaft diameter by 0.5 to get a radius. The other inputs could do this also, but I didn't bother. (This could also be skipped, but bolt shaft sizes are usually expressed as diameter rather than radius, which makes giving a diameter as input slightly more intuitive.) Turning the line segments into shafts is a simple matter of turning the computed radius into a circle and sweeping the curve with that using a Curve to Mesh node.
A Switch node allows the flange (which could also represent a washer) to be toggled on or off. This takes either the joined pieces of the head, or just the hexagonal bit,  and defines the instance geometry.
The final slightly-tricky bit is getting the heads to appear in the right places. I couldn't find a "correct" way to extract just the start nodes of each segment, so I use Curve to Points to get a set of points along each segment spaced a very large distance apart. (Practically speaking, since no segment will exceed this distance, this achieves the goal of obtaining only the first point.) The points' tangent needs to be folded, spindled and mutilated into the proper form to be used to orient the instances, which is accomplished with an Angle Euler to Vector node. This all is then fed into an Instance on Points to produce the individual heads, before finally combining everything with a Join Geometry node.
Obviously, the "make a flanged bolt head" and "instance on curve starts" bits are independent; the latter could be used to add any geometry to the start points of a set of curves.