text:
Multiple Textures in a Complex Object
For example a material I'm working on a material that has a total of three links (a 3 in the texture name field).  Is there a way to discover which objects have the other two shared links.  This is driving me nuts.  I have over 200 objects in my model and I have no idea which objects are sharing links.  I need to make them discreet.  So I click and make it discreet but every time I enter the material, it shows up as "3" again.
I'd love a capability to right click (or something) on an object and see which other objects are sharing those materials.
But I don't think that feature exist, so where can I find the other two objects using the material so I can make them unique and texture each individually?????
I believe this happened when I accidentally joined objects that were accidentally selected and all the materials in joined objects now share the materials.  But when you separate the joined objects, each of the separated object have all the materials of the originally joined objects.
This is nuts.
OK, all joined object keep their materials.  I get it.  But at the same token, when you separate an object "P-by selection" it would be helpful (incredibly helpful) if the separated object only kept the materials it originally had and the remaining joined objects no longer included those materials.
I can't tell you how many times I've joined object that were that were accidentally selected behind the object I was trying to join.  Later, I now see I have multiple links and I have no idea which objects share those links so I can make them unique and move on with texturing.
Instead, I'm playing were in the world is Waldo with materials without knowing which are the ones that are linked.
Is there a way to identify which objects are sharing the same material??
Thanks

http://blender.stackexchange.com/questions/23231/how-to-select-all-faces-with-the-same-material

The search function in the outliner window should do the trick.

If you click on "Search" in the menu you can also switch between "Case sensitive" and "Complete match"


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Can I create buttons in a blender panel with big icons?
I'm creating a panel with several buttons that start modal operators.  I'm finding the default UI layout creates very small icons that are hard to see, even if the source image is rather large. Is there any way to make things larger or include spacers and images?
class NormalToolPropsPanel(bpy.types.Panel):

    """Properties Panel for the Normal Tool on tool shelf"""
    bl_label = "Normal Brush"
    bl_idname = "OBJECT_PT_normal_tool_props"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'UI'
    bl_context = "objectmode"
    bl_category = "Kitfox"

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

        scene = context.scene
        settings = scene.normal_brush_props

        pcoll = preview_collections["main"]

        col = layout.column();
        col.operator("kitfox.normal_tool", text="Start Normal Tool", icon_value = pcoll["normalTool"].icon_id)

...

#---------------------------

preview_collections = {}

def register():

    bpy.utils.register_class(NormalToolSettings)
    bpy.utils.register_class(NormalPickerOperator)
    bpy.utils.register_class(ModalDrawOperator)
    bpy.utils.register_class(NormalToolPropsPanel)

    bpy.types.Scene.normal_brush_props = bpy.props.PointerProperty(type=NormalToolSettings)

    #Load icons
    icon_path = "../icons"
    if __name__ == "__main__":
        icon_path = "../../source/icons"

    icons_dir = os.path.join(os.path.dirname(__file__), icon_path)

    print("icons dir: " + str(icons_dir))

    pcoll = bpy.utils.previews.new()
    pcoll.load("normalTool", os.path.join(icons_dir, "normalTool.png"), 'IMAGE')
    preview_collections["main"] = pcoll

def unregister():
    bpy.utils.unregister_class(NormalToolSettings)
    bpy.utils.unregister_class(NormalPickerOperator)
    bpy.utils.unregister_class(ModalDrawOperator)
    bpy.utils.unregister_class(NormalToolPropsPanel)

I don't want to increase the size of the entire panel, just a few of the images.  I'd like to have more control over layout that just adding rows and columns of properties.

source: Stack Exchange

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

sort: votes


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How to have a keymap work in object mode and edit mode?
I've created an operator that uses a keymap to activate it.  While it works in object mode, it is not being called in edit mode.  Is there a way to get this to run in edit mode too?
import bpy

class GridRescale(bpy.types.Operator):
    """Change grid scale"""
    bl_idname = "kitfox.grid_rescale"
    bl_label = "Grid Rescale"
    bl_options = {'REGISTER'}

    def invoke(self, context, event):
        scale = bpy.context.space_data.overlay.grid_scale

        if event.type == "LEFT_ARROW":
            scale /= 2
        elif  event.type == "RIGHT_ARROW":
            scale *= 2

        bpy.context.space_data.overlay.grid_scale = scale
        self.report({'INFO'}, "Grid scale: %f" % (scale))
        return {'FINISHED'}

# store keymaps here to access after registration
addon_keymaps = []

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

    # handle the keymap
    wm = bpy.context.window_manager
    km = wm.keyconfigs.addon.keymaps.new(name='Object Mode', space_type='EMPTY')

    kmi = km.keymap_items.new(GridRescale.bl_idname, 'LEFT_ARROW', 'PRESS', ctrl=True, shift=False)
    kmi = km.keymap_items.new(GridRescale.bl_idname, 'RIGHT_ARROW', 'PRESS', ctrl=True, shift=False)

    addon_keymaps.append(km)

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

    # handle the keymap
    wm = bpy.context.window_manager
    for km in addon_keymaps:
        wm.keyconfigs.addon.keymaps.remove(km)
    # clear the list
    del addon_keymaps[:]

if __name__ == "__main__":
    register()

You can set the name to '3D View', demo here: Create keyboard shortcut for an operator using python? if that helps....? Otherwise you would have to declare another one for Edit Mode. Also note: some of your references are wrong, replace: bpy.context.space_data.overlay.grid_scale by context.space_data.overlay.grid_scale -> context is already passed by the invoke method invoke(self, >context<, event)

km = wm.keyconfigs.addon.keymaps.new(name='3D View', space_type='VIEW_3D') seems to fix the problem.

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


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Blender 2.78 with Windows 10 lags when interacting with the UI
Update
This has been confirmed resolved in a later version 376.33 and possibly the update prior. meta

Okay, I recently did a computer update. I used to run Blender 2.77 on a Dell desktop (5 GB RAM, 2.7 GHZ, Windows 8, build in graphics card). Since that computer wasn't fast enough for my preference, I saved up and got a new gaming laptop - the Asus ROG GL552 (Windows 10, 16 GB DDR4 RAM, Nvidia GeForce GTX 960M with 4 GB DDR5 RAM, 2.6-3.5 Ghz, and quad-core intel processor). That laptop has been known to have outdated drivers, so when I got it, I updated it to up to date Windows 10 drivers.
As soon as I started Blender, I immediately noticed its speed. Even doing simple things, like clicking buttons, or rotating the view with the middle mouse button, took too long to register in the program. I tried changing some User Preference System settings, but that didn't really help much. And the hardware seems to be fine - the render is lightning fast (renders the startup scene in under .1 second; it's just laggy when loading the uv screen), so I don't know why it's like this, or what to do. Also, I ran Blender 2.77 on this computer, and it was also slow (although it was fine on my previous computer).
It could be an issue with drivers perhaps (or maybe OpenGL?), but I ran Unreal Engine 4, and had none of the same issues - the speed was pretty decent on that; so I'm not sure why Blender would be so slow. Any help is appreciated - thanks guys!

Try going to File > User Preferences > System > Window Draw Method and change it to something else other than the default value. Play around with it restarting Blender between changes see if any of those work better.

Sadly that didn't fix it :(

Same solutions as below, I updated my XPS 15 (same 960M) to latest drivers and Blender is unusable. Rollback for now or force using the intel chipset which I wouldn't recommend.

See the current driver release thread here, the problem has been mentioned several times. Will personally monitor and update here https://forums.geforce.com/default/topic/978895/geforce-drivers/official-376-09-game-ready-whql-display-driver-feedback-thread-released-11-28-16-/1/

I found the solution, right click on the blender shortcut>Run with Graphics Processor>Integrated Graphics. It should run smooth when you do that. No need to roll back any graphics drivers, just use your integrated graphics to model and you can still set your 960m to render in the settings.
In case you are not able to see the option, Open NVIDIA Control Panel, from the Desktop menu and check 'Add "Run with graphics processor" to Context Menu'

Had the same issue on my Alienware 15 R2, which is stacked nicely. But right after the driver update, things went into snail mode. Tyler N hit the nail on the head, run it with the integrated graphics and it immediately went back to fast and smooth!

U da man!! Thank you so much, Tyler - I did that and had to open the Nvidia Control Panel. I then added Blender to the list of programs to customize graphics settings - and it worked!! Thank you so much again!

But will that make Blender rendering any slower since it's not using GeForce graphics to run the program?

@josepharaoh99 it shouldn't, the i7 6700hq should run the program fine with the hd 530 integrated graphics when you're just modeling in solid mode; as long as your projects aren't crazy intensive, it should work fine. Just make sure you use your 960m when rendering by going to File>user preferences>System>compute device>cuda and then in if you're in cycles mode, make sure you change device from cpu to gpu compute under the render drop down menu under the properties panel on the right side of the UI. I'm using the same ROG laptop as well but with 2GB of vram, and blender is working great so far

@TylerN i do not have graphic hence that option run with graphics is not available me to having the same problem its lagging 2.78a. When i install new 2.78a after few second it close and kick me out to desktop then i download opengl and paste in blender exe folder it work but problem is now to lagging and some time it stuck and work.  2.77 work perfect same system different version different result. Any solution

There is no such option for as "Run with Graphics Processor" in the  NVidia control panel for Desktops.

Thanks, that saved my day after all, as I could not figure why blender 2.79 was responding to every change with a two seconds delay!!!

I don't have enough reputation to comment on Sam's post, but he's right. I wanted to stream a game last night and downloaded Nvidia's Geforce Experience for Shadowplay (which updated a driver). Opened Blender this morning and had the same issues (extremely delayed input). Rolled back the driver and working fine again!

Ironically, this answer might get you more than enough reputation to comment lol.

Yeah, it worked. If we speak about this driver, I wonder also if You guys have sometimes vertical lines showing on screen after update?

Have the same computer specs on a Dell 7559.  Had the same problem when I updated the NVidia drivers to the recent Geforce Experience ver 376.09. I finally uninstalled this driver and went back to the ver 375.95 and things are back to working.  Hope this helps!

Unfortunately, the 375.95 driver doesn't support Windows 10, and I'm very uncertain about changing to out-of-date drivers (because it might cause problems on my computer), but I'm willing too if I can find a W10 one known to work with Blender.

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


text:
Cannot right-click to select sometimes
I am using Windows 7 Blender 2.77.
I am in edit mode, solid mode, selecting faces, I still cannot right-click to select faces on my mesh.  When I change to wireframe and right-click, I am able to choose a face and make it snowy-white dots.  When I choose shift+choose a second face, the first face becomes orange and the second face becomes snowy-white dots.  When I change back to solid, the faces remain the same color as in wireframe.
Selected faces are supposed to be orange.  Why are they snowy-white in Wireframe mode and impossible to choose in Solid mode?
I tried "Load Factory Settings," and my graphics card is Intel HD so I don't have full screen anti-aliasing, whatever that is. (referencing 2 stackexchange answers I have looked up)
Photo 1: Right Clicked the Face in Solid

Photo 2: Right Clicked the Face in Wireframe

Photo 3: Shift + Right Clicked another face in Wireframe

Photo 4: Changed back to Solid mode

Can you share your model here http://blend-exchange.giantcowfilms.com/ ? It would help to spot what's wrong.

I don't think that would help, it is actually happening on all of my files.  I will try though

It looks normal to me in that the last pic still shows the highlited face but in solid mode it's mostly hidden behind the handle.  The white speckly appearance indicates the last face selected on my machine.  In pic 3's case, the surface behind the handle would be the last face selected.  As for being unable to select surfaces, I've noticed this problem and have had to flip that face over. Goto wireframe if necessary to select the face in question, open the Tools panel at left with "T", then open Shading tab, click on "Flip".

Comment cont...  You can also select problematic faces by getting to it's other side.  Often this means moving to the inside of the model itself.

OK Thank you!  I just thought I was missing something, it does work for me to go select things in wireframe.

@Hanry Hu: the downloaded file is slightly different from above, in that the cup and the holder seem to have been merged (and then subsurfed). Btw, I can select (right click) faces normally there even in solid mode. I tried to reproduce above setup, but again, face selection works in that area, even in solid mode...

Yeah, I edited it using the wireframe, but it didn't really matter because I still can't seem to select faces in solid mode.

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


text:
How to create little flanges on the bottom of the bottle
Can you please help me understand how to do it the right way? :)

Trying to make glass can:

Can you please help me understand what you want to model? A reference image would be very useful here. Because I do not understand what you are trying to get to from that diagram.

What kind of bottle is it?  Medicine, beer?

@David
Added image

It the geometry isn't required, just the look of it when rendering, perhaps you can get away with a Displacement Map ?

You may do it fast using the inset tool.

Add a circle with 72 vertices- set it in a Tool Shelf (T).

Extrude it inwards (E) and add two edge loops (Ctrl+R). Select the whole face loop with Alt+RMB, then press I twice and set the inset's scale. Finally extrude the inseted faces upwards, add addictional loopcut in the middle and rotate it a bit (R).

Add a subsurf modifier (Ctrl+3 in Object Mode). Lower the middle loopcut a bit. Press Ctrl+Numpad+ to increase the selection area. Press Shift+E to crease it. Finally add a smooth shading and recalculate normals if needed (Ctrl+N).

A possibility to do that is to start from the base shape, add an array modifier then a simple deform modifier to make a circle:
The base shape is not really readable on your schema but I try to make something close and to show the principle, in two steps:

The base setup
An optimized setup

Base shape
Add a square with some modeling. Here I use I to inset, AltE to extrude individual faces, S to scale. All using "individual origins" as pivot point.

Adding the modifiers
We use first an array modifier, set it around to 32 steps as this is often the setup for a circle. We adjust the offset so that the array is joint and check 'merge' to avoid doubled vertices between the duplicated parts.
Then add a "simple deform" modifier, set to "bend" with a base of 360° that we'll can adjust to close the circle.

The bottom of the bottle
Add a subdivision surface modifier to check the smooth aspect and if the look is the one you want.
Apply the two first modifiers (array and simple deform).
Close the shape by removing the doubled vertices at the junction.
Extrude and scale ES.

That could be close to want you want (?) but even if this example is less detailed than what you need, it already has many vertices:

Optimization
To optimize it, we will merge three base parts and reduce the geometry around:
We begin by decomposing the array. From 32, we go to 3 x 10 (for instance). Then adjust the offset.
We now have a base of three shapes:

On each side, from the 4 border vertices, we make so that only two are on the border:

Now, do the same as for the first model: apply the modifiers, remove doubles:

We have "tris" here. We'll remove it by selecting one edge, the all the others by similarity (ShiftG) then dissolve X them:

So that, we have a base bottle with the same level of detail for the flanges but lower for the bottle itself:

The result:

another example:


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generated circular UV map
I am struggling a bit with uv mapping. i wanted to texture this circle but i get this instead of a perfect circular wood texture... i even tried spherical on color node but it doesnt seem to be the right way!

https://blender.stackexchange.com/questions/74041/how-to-perfectly-align-uv-coordinates-automatically https://blender.stackexchange.com/questions/92812/how-can-i-assign-an-image-texture-gradient-along-a-circlular-ring

thank you . your answer worked for me

You can select the side and use the Unwrap > Cylinder Projection. As for the front sides, first unwrap, enable the UV Squares addon, and click on the To Grid By Shape button:

Result, the texture follows the shape:

it worked! thank you so much moonboots


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In geometry nodes: moving instances relative to one another in sequence, and with individual control of rotation
I'm trying to rotate individual objects using GeomNodes. However I want to control how much each one rotates. Also every object should rotate with respect to the one in front in a vertebrae kind of way.
This is the start position:

I have tried the following node arrangement:

This is the result. It works for the first two rotating cones, but for the last one not. it appears to be offset for some weird reason:

Not and answer, because geonodes might not be the right tool for the job. Have you tried using an armature? this kind of thing is what armatures and constraints are for, setting this up would only take a few seconds.
If not applicable, please explain what your end goal is.

Im using Geonodes bc I need them to rotate using a mathematical expresion that would be added after. With an armature is very simple, but to imput and extract the mathematical data would be very tedious manually (since I need to do it for different models) when I could potentially do it in geonodes...

You can control bones with expressions as well, using drivers.


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Proportional editing snapping not working
sorry if the title is confusing but I'm beginning to learn blender and I'm on video 4 of the blender guru donut guide and trying to make icing dribble but snapping wont work and when i try to model the icing it clips through
https://youtu.be/Ou_uAuHxxuY (sorry for the horrible quality)

Two things in your video: Did you turn off the Cage option on the Solidify modifier so that you could see what you are doing (https://youtu.be/R1isb0x4zYw?t=65) and did you turn on the Project Individual Elements on the Snapping menu (https://youtu.be/R1isb0x4zYw?t=252)? The links point to the times in the video where it is explained. You are using version 3.6.5 so you need to select 'Face Nearest' on the Snapping menu as he explains in the first comment below the video..

Pointing at tutorial on YouTube does not mean that everyone has seen it. The version of Blender could be older than the one you are using. Check for changes between versions. For best results, 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. Make sure to edit your post and include screenshots showing the problem or write down steps that lead to the issue.

@RumenBelev I think I've covered all the issues that the questioner has, including the Blender version number difference between his one and the one Andrew was using in his tutorial. For what it's worth, the link to it is here.

Hi John, thank you for your answer. It is just a good practice to provide a clear explanation within the post itself. This way future readers will get the questions and answers without having have to leave the page and visit other websites following links that may expire.


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Automating minimum scale (of volume for said part) for fine detailed objects are going to be 3d printed
I am working on a project in Blender which is fairly simple, using sappling tree gen, solidify and bevel to create a printable 3d sculpture.
One thing I'm unable to solve using the above features is that inevitably I can't without making the model look completely alien achieve scaling of minimum 1-2mm3 for branches apart from with a ridiculous amount of manual sculpting which often leads to failure. (This is on my part for not being good enough with the tooling to solve some of blenders slightly more difficult non-manifold edge issues).
Is there a way to programatically/procedurallly/use tooling to effective scale any part of the model that is below x mm in width, height or depth.
I know I should probably be quiet and get on with the hard work but I can see this kind of technique being very useful for various miniature scale models (4-10cmm xyz with extremely fine details.
Any help much appreciated!

I want to say using simulation nodes or you can have a look at selections based on values https://www.youtube.com/watch?v=BTFD1fnTVtk

Thankyou, this has helped me get started. Think I'm on the right track but have a lot to learn about geometry nodes.


text:
Problem baking normal maps in blender

The image above is the normal map post-baking.
I've been following blender guru's anvil tutorial but can't seem to figure out why my the baked normal map lacks all details and comes out white like this, I've noticed the baking progress tracker get's to 25% or less then instantly skips to the end.
I made sure to have the low poly model as active, click on selected to active and select the images node in the shader Editor before Baking. Still nothing. Please help.

Hello please shareyour file: https://blend-exchange.com/

Seems as if this could be a bug... are you experiencing this when baking with GPU while baking with CPU (although slow) works? That is happening in this question here (cannot mark this one as duplicate since the other has no answer yet): GPU Compute breaks after trying to bake normal map

@GordonBrinkmann I Switched to CPU mode on cycles and restarted my PC and the bake now works.

@Silver-will But it does work only in CPU mode, or GPU as well after restart? Still a bug then, it should work with GPU, too...


text:
How do I make the spacebar menu display nodes in the Node Editor?
(using Blender 2.79b)
Almost invariably, when I watch a video on Cycles material nodes, they have an ability to hit spacebar, then type the name of a node to add that node to the editor. For example, Space+ramp pops up a Color Ramp node. An example of this is shown below:
When I try this, though, all I get is this:

Googling told me about a plugin called "Dynamic Context Menu," but that does not allow the desired type-and-select functionality.
To clarify, I can add nodes with Shift+A and hunting through the menus that way; I simply want to have this much more efficient way of accessing them.

There is keymapping which makes it possible, see https://gist.github.com/bitinn/22f6fefe026d8d9e83468864edb8f835#node-editor-specific. It is possible to grab only that functionality from the keymap as well if the rest is unconvinient (or just create one yourself as in the answer below)

I'm not sure if the node search by name is on default on the Spacebar. However you can assign it any shortcut you want.
By default, you can access the search by pressing ⇧ ShiftA > and then selecting Search. Your presented searchbar will show up and show the nodes as results.

(I consider it possible, that the makers of the tutorials you mention, simply pressed clicked the search option too fast for a frame to capture.)
If you wish to add an even more direct shortcut to this functionality, go to the User Preferences ⎈ Ctrl⎇ AltU. Scroll down to the Node Editor and add a new shortcut. Assign a key combination to it and enter node.add_search into the identifier field.


text:
How to make ripped/torn cloth?
I want to make a simple tear in a piece of cloth (the cloth itself was made with the cloth sim) Ideally, the torn strip should hang realistically, but I don't need it to be animated.
I'm aiming for a threadbare look, as shown below, with the little bits of string fuzz around it.

I also need the torn fabric to be hanging down, not just a hole in the model/texture.

Is there a tool or add-on to do this "simply," other than manually modeling it? If I do have to make it by hand, how should I go about doing it?

Such effects are usually achieved with uv mapping a texture and alpha channel. It also depends on how close up your audience would see it, real close up may require some modeling.

@hawkenfox I need the torn cloth to hang down in strips; edited post to clarify my question,

@ Somatic You do realise the question you asked may require a full length tutorial right?

I would combine the two options above, and use use the V key to rip edges in edge select mode to outline the strips that will fall. I would still suggest alpha texture to get the edge roughing and then possibly look at the stuffed animal tutorial on CGCookie, using particles for the fuzzy stuff. Of course, the cloth sim would need to be rerun or manually unfold the strips. You might add some weight to the vertex group to make them hang.

Once I rip out the cloth strip, can I make it hang naturally by applying gravity? I looked in the Blender docs, but the only place I could find cloth gravity was in the 2.4 manual, and it seems like the feature was removed in later versions.

You should be able to weight paint it and run your simulation again to recalculate for gravity - weight painting should allow you to add weight to the strips

authors: Глеб Потапов


text:
How do I scale down/zoom out an environment texture?
I have a large environment texture of space that I'm using as the background of my scene.

However, when I try to use it in my render, I can only see a tiny part of it.

I want to scale down or "zoom out" on the texture, so I can see more of it in the rendered area. I tried to use a Mapping node and scale it that way, but it did nothing (I could rotate, but not scale).
This is my node setup:

The image is 4.66 MB, 4533x2618 pixels. Render resolution is 1920x1080 at 100%, if that's what you mean by "render size." I'm not using any compositing nodes, but I did add the nodes used for the world shader.

Vector Mapping node is the correct way.
Make sure you are using an Environment Texture node connected to the Generated socket of a Texture Coordinate node. Then use the Vector Mapping X or Y scale to control it.

The trick is making sure you scale only in one of the three axis at a time, otherwise it will yield no visible effect.
Also have in mind that this will introduce some stretching distortion that may be more visible in certain directions, as spherical environment textures can't really be "zoomed out" in the traditional 2D image sense.
Correctly zooming out would require actually moving the physical camera in relation to the background subject and the image would need to be captured again from a different point in space, yielding a slightly different perspective. This cannon be correctly simulated with bare image transforms or manipulation, and is thus an approximation.

Okay, so the trick is to only scale it on one axis (just the Y, in your example). When I scaled it on all the axes simultaneously, it did nothing. Thanks!

The scale mapping solution only works if you don't have to look around with your camera, otherwise you will notice the sphere-like background image has been stretched.
A correct way to do this scale is actually changing the Field Of View (or Focal Length in blender) of your camera, for this:

Select your camera
In the 3D Viewport: Right Mouse Click > Camera Lens Angle and drag

or

In the Properties panel click the green camera tab, in Lens section change the Focal Length field

This definitely produces superior results.  No odd distortion and 3D objects in the scene will be affected appropriately.

Another way I would try is to tile the texture, make the texture tilable in photoshop, then set it to half scale, so the image repeats, this works best with backgrounds that you don't have a ton of unique details or don't move the camera around to see the repeating image.
The way I would do it is to add a wider additional part to the image, of say just stars, which will then compress the part you want to see into your field of view.


text:
High subsurf crashing cycles render
I have a fairly simple scene - large ground plane, five uv spheres, Pro-Lighting envmap - that's consistently and almost instantaneously crashing Blender on render.
From my tests, it seems to be a result of a very high subdivision on my primary ground plane (which is approx. 2.8x7 blender units with around 54k verts), combined with a high subsurf level (for microdisplacement). It handles a Level 3 Level 4 subsurf fine; crashes almost immediately at Level 5.
I've done a number of large scenes with millions of verts on this machine before (scene + 20k object particles, with randomly between 1500 and 17k verts each) and while it takes forever and an age to build, eventually it cranks through and renders just fine. I've had a few slow almost to a complete standstill for a while, but I've never had one crash outright.
I know someone is going to quote the subsurf exponent table to me, and I acknowledge that it's almost ridiculously high, but I do legitimately see a difference in the scene at that level.
Given that it crashes almost instantly, as soon as it attempts to synchronize that mesh object, is there a mathematical limit that it's hitting before memory even comes into play (this is a 16GB system)?
Is there some internal limitation to the number of vertices a scene can trigger via rendertime subsurf?

You are using the microdisplacement build? It is known to be buggy.

No, just trying to fake it. This is stock 2.77, Supported features only.

Surely you don't need all of that terrain to be subdivided that high (?). What I've done in the past that worked well is subdividing the terrain near the camera more. So very near terrain was hi-res, somewhat near terrain med-res, and distant terrain low-res. If you need to animate the scene, you might try creating a hi-res version of the terrain and use it to bake a normal map for the lower res one. Also, I'm curious - does your mesh have a very hi-res texture on it? Very hi-res textures are known to crash Blender, probably more so than hi-poly meshes.

Believe it or not, I'm already breaking down the terrain by distance, although it could probably always be chunked down further.
Most of the textures I'm using are from Poliigon and are 6K or less. I've been using these for a while without issues, but I am scaling it on the ground plane x100...who knows. It's an intense scene I guess.


text:
Remote rendering on the cheap
Environment is a high school. We have older macs that have no graphics cards, so student animations (Blender 2.74) can easily take 3-5 mins per frame. I managed to procure a decent win7-based server with a decent graphics card.
Is using the win7 machine for rendering as simple as 1) Having the macs save the .blend file to a shared directory, 2) running a cron-like job on the win7 machine that looks for files to render and, 3) launches command line blender (maybe cycles rendering) with additional arguments to output to a different shared directory students can check in the morning?
Added:
Yes, it does work fine, 'server' computer is fast enough. Command line i ended up using is:
blender.exe --background {student .blend file} --render-output C:\BlenderOUT{student filename w/out extension} --render-format QUICKTIME -E CYCLES -x 1 -a
where {xxxx} is specific to the job and C:\BlenderOUT\ is a shared directory students can check for and retrieve their animations.

It would probably work. I think it should open up the blender file in blender, and then render it from there. That sounds great, but will the computer be able to render a whole classful of animations? Good luck!

Great, thanks for the answer! If the machine isn't fast enough, i guess we'll find out.


text:
hair particle textures
any way to texture hair particles mid strand? like have brown hair with white frosted tips or a pink star in the middle?

Is this what you are looking for? http://blender.stackexchange.com/q/18970/599

If I understand what you want, yes. Please give some sort of reference or more information.

Thx I'll give those a try otherwise I will try to build an example I what I need if these don't do what I need - though these answers should work. Thx vm for the help and answers.


text:
Cinema 4D style navigation
I was using Blender with Maya configuration preset and it worked great for me, but since in 99% of Blender tutorials people are teaching using default configuration preset I've decided to switch on it.
I've bumped into a few annoying things:

Using Maya preset I could press the F key to focus on the selected item/vertex/face and zoom, pan, rotate around it. In Blender preset it's almost the same with the Del key, but I can zoom only using mouse wheel (which is extremely uncomfortably for me), if I use Ctrl+MMB zoom, the focus resets.
Sometimes I can't even zoom or pan properly, it starts behaving very slow so I have to refocus with the F on the different objects to reset this bug or whatever this is.

Is there a preset or an addon to make Blender behave like Cinema 4D. In Cinema 4D the focused object/vertex/face is always the one mouse is pointed at.

There's a such hotkey - Alt+F which lets you zoom to current mouse position and rotate / pan etc. around it. It works in every interaction mode except for the Edit mode. It's possible to use it on the fly without any user prefs changings.

You second bullet is a common problem present in pretty much any 3D software, it's explained quite nicely in the question and answer.

Yes your solution would be to

Go to user preference > Interface > View Manipulation ...
Turn off "Rotate Around Selection"
Turn on "Auto Depth", "Cursor Depth", "Zoom to Mouse Position".

Now when you zoom take care to place your mouse at the object where you want to zoom or rotate around. It will now no longer slow down zoom when you hit a threshold. Instead it will always trys to determine the depth relative to your mouse position to any 3d surface you point the mouse cursor at.
Rotate around Selection is deceiving ... it gives you the notion that you would be rotating around a selected element. In reality the tool only rotate around the element when you zoom to selected first. Moreover when you select your next object it will use the formal element's scene depth. This is ok for single element selection, it however proves ineffective when you need to select multiple objects which just happens to be far apart.


text:
How to move the master bone of a rig to the actual pose?
I have just started animating with Blender. Now I have a question:
I have imported a MakeHuman Model of a person with the default rig. After that I posed the rig and created a stand up animation. So first, I moved my model in object mode to the start position and rotated it by 90 degrees. Then I made the animation, at the end of the animation the model stands next to the bed.
This works fine, but ...
Now the model stands there, but the master bone of the rig is still at the original position.
So how can I move the master bone to the rest of the rig, without changing the pose or the location of the model?
Thanks for help!

You never move the rig in object mode, you want to use the Root/Master bone exactly for this and also you never move the rig away from the Root/Master.
The reason is when you only animate bones, you get only 1 Action. Whereas when you animate also the object you get 2 Actions and it's messy. Can be problem when the rig is linked and you need to apply animations to the proxy. You also can't save such pose to pose library. Etc. this can go on and on why not to do it.
There is no easy way of fixing it. You will have to investigate what bones are parented to the Root/Master, move those bones back and position everything with the Root. And if you have animation do it for every keyframe.
If you have lots of keyframes it might be better to bake the animation. You do this by creating and parenting an empty to each bone that is parented to Root(local axis should correspond). You then bake animation to the empties. Then you move (and animate) the Root where you want it and override the transforms of parented bones with Copy transforms constraints from the empties. Then you bake the animation to the bones and you delete the empties.

I didn't animate the object in object mode, I just moved the model to the starting position in object mode. The position of the origin never changes.

@Erich If you move something in object mode the origin changes. What you said doesn't make sense. Can you clarify? Maybe with a picture?

I meant, during the animation the origin never changes.

@Erich Oh, ok, if you don't have any keyframes then your job is much much simpler. You just need to re-arrange things so the Master is at the right place and everything has correct translations/rotations. To do this exactly/precisely you can use helper empties to remember where things were when re-arranging.


text:
Render and save " view port render image (openGL)" with python directly?
on which can save and load custom props (drive shape keys) and pose bone transform for Armature characters as preset.json with some options.
Then I hope to enhance it by generating preview images (jpg, or png) with json.
(eg When I save "preset.json" from add on UI button,it will auto generate preset.png of current scene preview)
I suppose I can use the bpy.utils previews submodule (bpy.utils.previews)
but do not know clearly how it actually works. What I hope to know is, if there's a function which can generate the preview at a user-defined path.
I suspect I can mix the funciton with my custom operator class to save json (so when save the json, same name image file will be genrated as perview)...
If someone has experience with this, would you teach me how you achieve it (with simple code)?
I suppose I may need to use the bpy.utils.submodule (bpy.utils.previews) but even though I read the docs and example (which uses the image as UI widgt, which I don't need, I only need to know how to generate a current scene preview as image file)
//////
Though my final goal is same, I took some of the steps and made a few changes...
What I planned is,

render and save viewport as open GL image with current user scene settings, when you save "preset.json" from my add-on's UI button

Then I hope to make render and save function, which renders the view port (Open GL) image and saves the image "without image editor>render-image>save"
I plan to use bpy.ops.render.opengl(), to render a thumbnail, is there good way, "without opening the image editor(Render image) and choosing slots" but saving to the directory with file name, as arguments?
Has someone already built a simillar (simple) custom function?

Have you seen: Batch generate preview/thumbnail image for old files? already?

Thanks link, yes it teach me some new things, but I feel it is not really what I need.

MMMM,, I expect if there should be more simple module function, which I simply generate current scene thumbnail with some arguments ^^;

It was actually easy. thanks there is already arguments, to direct output render-image in bpy.ops.render.opengl()  (write_still = "True")
then most simple case (if keep current scene render setting), once change path(file name) to render thumbnail(openGL view image), then after generate the img , return path as same as before. (so user may not notice it changed)
import bpy

def render_icons(fname):
    render = bpy.context.scene.render
    upath = render.filepath
    render.filepath = fname
    bpy.ops.render.opengl(animation=False, view_context=False, write_still=True)
    bpy.context.scene.render.filepath = upath

I suppose, to enhance this, untill render, set some render propertys of bpy.context.scene.render to fit as thumbnail, then return all property as same as before.
and add option flag (user may manually set those setting, or use preset for icon render)


text:
Disable collection on all layers except one?
I have 10 layers and every time I make a new collection I have to click on each layer to exclude collection from every layer. For example, I created collection on layer 1 and need it to be enabled only on layer 1. Is there an option or hotkey to exclude collection from all layers except this one?

You can just click and drag down/up and it will select/deselect multiple at a time.

I need smth like this https://blender.stackexchange.com/a/160759/60139 but i don't understand anything in coding and when copy-paste the code it does nothing

The following Add-on code can do this for you. Save the code as oco.py and install that file as an Add-on in Blender. You can then activate it when searching for Collection Ops in the Add-ons section of Blender.
Once done, right-click in the Outliner on the collection you would like to exclude for all other View Layers and select the command on the bottom:

Here's the Add-on code:
'''
Created on 09.07.2019

@author: r.trummer
'''
bl_info = {
    "name": "Collection Ops",
    "author": "Rainer Trummer",
    "version": (0, 1, 0),
    "blender": (2, 80, 0),
    "description": "provides functions in the Outliner context menu to work with collections",
    "category": "Object"
}

import bpy
from bpy.props import BoolProperty

#===============================================================================
#    Operators
#===============================================================================
def get_flattened_layer_collections(layer_collection):
    for c in layer_collection.children:
        yield c
        yield from get_flattened_layer_collections(c)

def find_layer_collection(view_layer, layer_collection, **kwargs):
    pool = kwargs.setdefault('pool', view_layer.layer_collection)

    colls = get_flattened_layer_collections(pool)

    for c in colls:
        if c.collection == layer_collection.collection:
            return c

class COLLECTION_OT_Unset_For_Other_View_Layers(bpy.types.Operator):
    bl_idname = "collection.unset_for_other_view_layers"
    bl_label = "Exclude In Other View Layers"
    bl_description = 'excludes collection in all other view layers'
    bl_options = {'REGISTER', 'UNDO'}

    deactivate: BoolProperty(default = True)

    def execute(self, context):
        for vl in context.scene.view_layers:
            if vl != context.view_layer:
                vl_collection = find_layer_collection(vl, context.view_layer.active_layer_collection)
                vl_collection.exclude = True

        context.view_layer.depsgraph.update()

        return {'FINISHED'}

#===============================================================================
#    put the commands into menus
#===============================================================================
def draw_outliner_collection_commands(self, context:bpy.context):
    layout = self.layout
    layout.separator()
    layout.operator(COLLECTION_OT_Unset_For_Other_View_Layers.bl_idname)

#===============================================================================
#    registration code
#===============================================================================
__classes__ = (
    COLLECTION_OT_Unset_For_Other_View_Layers,
)

def register():
    for cl in __classes__:
        bpy.utils.register_class(cl)

    bpy.types.OUTLINER_MT_collection.append(draw_outliner_collection_commands)

def unregister():
    for cl in reversed(__classes__):
        bpy.utils.unregister_class(cl)

    bpy.types.OUTLINER_MT_collection.remove(draw_outliner_collection_commands)

if __name__ == "__main__":
    register()


text:
How to update an object after changing its uv coordinates?
I'm creating a node for Sverchok which will apply custom UV map to an object. Pretty simple thing but after applying new UV coordinates to an object object it doesn't update the viewer somehow. Switching to Edit Mode works but I'm sure there is a better way.
The problem can be reproduced this way:

Create a default plane and apply any material with a texture like this:

then call the code for assigning new UV coordiantes:

import bpy
obj = bpy.context.active_object
new_uv = [(0.5, 0), (1, 0.5), (0.5, 1), (0, 0.5)]
obj.data.uv_layers['UVMap'].data.foreach_set("uv", [n for v in new_uv for n in v])
print('Done')

However, the changes are only applied when switching to Edit Mode:

This is a simple fix - all you need to do is run the update() function on the object's mesh data: obj.data.update()
Depending on your intended use case, you may also need to run bpy.context.view_layer.depsgraph.update() to update the dependency graph.

Thank you so much. obj.data.update() is exactly what I needed to perfectly pair with bpy.context.view_layer.depsgraph.update(). Any reason you prefer it over bpy.ops.wm.redraw_timer(type='DRAW_WIN_SWAP', iterations=1)?


text:
Seperate faces from mesh without creating new parts?
This has bothered me for so long... I like to seperate some faces from my mesh but without creating a new mesh or part, I could press P and Seperate by Selection but then I have to switch to Object Mode, join them and swtich back to Edit Mode. Too many steps for my lazy butt... I could duplicate those faces, hide the duplicate, delete the original faces and keep the duplicate but it seems unconvinient.
Is there no magic button I'm unaware off?

I guess you misformulated it, you want to separate a part of the mesh, not separate objects, so Gorgious is right, use Y

With the object selected, hit Tab for 'Edit Mode'.
Press 3 for 'Face mode'.
Select the face/s you want to separate.
Press Y to Split - or if you don't want to use the keyboard shortcut:
Look for the 'Mesh' tab at the top left.
Click for drop-down list, find 'Split'.
Hover over 'Split' for secondary drop-down list.
Select 'Selection'.

Done.


text:
What causes fire to gradually turn off or disappear?
I use blender 2.80 (The old smoke simulation). When I bake the last 251 frames of the movie, the fire works well then, it gradually turns off!
Click here to download the blend file.
Here are the steps to reproduce the issue:

Bake.
If you navigate before frame 9039 you will find the fire in the rendered image.
Around frame 9039, the fire gradually disappears or turns off.
At frame 9060, the fire completely disappears in the rendered image.

I need the fire to last until frame 9172 so the fire should be present in this range (8922-9172) without getting weak, disappearing, or turning off.
Q: What causes fire to gradually disappear?

Another link to download the .blend file: https://filebin.net/doj0vhd0eggo686a

In this case it is camera distance. But, instead usual camera distance, that is located in camera settings, this is volumetric distance, that can be adjusted in render settings

OMG that's awesome :) I spend more than a week playing with the domain and emitter settings and also some other settings. Thank you so much.


text:
How to avoid mesh anomalies after Knife Project
Using Knife Project to have some windows and doors in an aircraft fuselage, however the cut produces these anomalies around the window corners, where the triangulation is, that I cannot find a way to avoid or remove. Is there any way to get rid of these or at least have it less visible? Thanks.

About the "why", some explanations here. But for practical case, you should upload your file (or the needed part of it), so that we can help you to find a solution. Please use this link: http://blend-exchange.giantcowfilms.com/

@lemon I think you missed a link in your comment.

@mrborzoo To avoid "mesh anomalies" use a proper modeling technique instead. Knife project is a "lazy" method of modelling, it will inevitably create bad topology and issues.

In the comment above, I missed to add this link http://blender.stackexchange.com/questions/74656/cant-disolve-edge-and-faces/74660#74660 (thanks @DuarteFarrajotaRamos)

This can help also as "corrective" approach http://blender.stackexchange.com/questions/75858/how-do-i-prevent-overhangs-when-using-subdivision-modifier/75871#75871. But as said by @DuarteFarrajotaRamos, knife or boolean operations are some kind of lazy method (at least in Blender), so better topology is needed here (for instance, look at https://www.youtube.com/watch?v=Bc52fcrHvAA)

Added the blend file. Regarding topology, I can't have a complex mesh since this is for the FOSS FlightGear simulator, so I suppose it will be very difficult to have only quads and keep it light.

@mrborzoo... ok for the file, but do you have to model before the knife cut? Because remaking it from what is in your file does not lead to the same result...


text:
How to apply custom lens distortion parameters to a rendered image?
I want to render the depth map of a mesh I created from a 3D scanner. I already managed to render my image and it is nearly fine.
However, I also want to apply a lens distortion to my output (the image should appear as if it was created by a camera with certain parameters). All the camera parameters (K1, K2, P1, P2, K3) are known, but I can't find the option to enter them. I already spent quite some time studying the documentation, searching this site, and reading/watching tutorials. However, my settings/properties look quite different than in all explanations.
It should look somewhat like this:

(see How to determine lens undistortion values for motion tracking? or Tutorial on YouTube)
Instead, my settings look like this:

The distortion nodes "Lens Distortion" / "Movie Distortion" didn't really do the job as I have a more complex distortion model (radial and tangential up to order three).
Related similar question:
Customize blender camera distortion

First screenshot shows 2.7x and the other - 2.8x. Both don't seem to show identical settings. Do you mean you can't find Calibration option in 2.8x?

Yes, kind of. The 2.7 screenshots are from other tutorials, the 2.8 screenshots are mine.  brockmann's solution worked fine for me.

You can enter the distortion data per loaded 'clip' in the 'Track' panel of Movie Clip Editor (N) and use a Movie Distortion node in the Compositor to distort your image based on the values:

I'd suggest go to the 'Compositing' workspace, enable 'Use Nodes', switch the editor type of the 'Timeline' to 'Movie Clip Editor', load any arbitrary image with the same aspect ratio, set your values for K1, K2 etc. and add a Movie Distortion node to your node stream in the compositor.

That's what I was looking for. Thank You!
But apparently, there is no option for tangential distortion (p1 and p2 in most notations), right?

Glad I could help. Not exactly sure what tangential distortion is. However, there is a new distortion model implemented as of Blender 2.90 which might help or/and should be a good starting point on how to implement your own custom model. Patch: https://developer.blender.org/D7484 @Gnnr

Wow, that would be quite a task for me, but I will consider it...
FYI @brockmann: Tangential distortion happens when an image sensor is not exactly parallel to the lens (which is to some degree usual due to production tolerances).
See here: MATLAB Explanation (scroll down to just before the references)
or here: OpenCV Documentation (scroll down just below the figure of the pinhole model)

If the new model doesn't help, you can try to reach Sergey over on https://blender.chat/ Thanks for the links, on my reading list. Also consider that cycles is using a pinhole camera Cycles generates distorted depth Anyway, keep me posted @Gnnr


text:
Speeding up scaling about the true center with a mirror modifier
I know there's a way to scale along the median point of an object's virtual geometry and actual geometry combined, which is here:
Scale about true center with Mirror modifier
But it's not very quick, especially if you have a lot of parts to scale near the center of your mirrored mesh. Quicker means better productivity, so it should be in my interests to become quicker while keeping quality high. Is there something I can use, maybe Python code or a plugin, to allow for this or a similar process to be done automatically, for example, when I select something and press a keyboard shortcut?
Thank you very much for any help. :)

Second answer offers rather quick solution on that. Something more quicker could be only to select edge loop located on the mirror plane and snap cursor to selection (use cursor as pivot point)

Here's a quick little addon which streamlines the process outlined by your link:
# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####

bl_info = {
    "name": "Snap Macro",
    "author": "Me",
    "version": (0, 0, 1),
    "blender": (2, 78, 0),
    "location": "View3D > Snap (Shift S)",
    "warning": "",
    "description": "Snaps Cursor to Selection, Sans Axis of Symmetry",
    "wiki_url": "http://i.imgur.com/j1N3Wqz.jpg",
    "category": "View3D",
}

import bpy
axSym = [
    ("0", "X", ""),
    ("1", "Y", ""),
    ("2", "Z", "")
    ]

def snapMacro(self, context):
    bpy.ops.wm.context_set_enum(data_path="space_data.pivot_point", value = "CURSOR")
    bpy.ops.view3d.snap_cursor_to_selected()
    context.space_data.cursor_location[int(self.sAxis)] = 0

class snap_macro(bpy.types.Operator):
    """Macro snaps cursor to selection and zeroes X-Axis"""
    bl_idname = 'view3d.snap_macro'
    bl_label = 'Snap Macro'
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(cls, context):

        return context

    sAxis = bpy.props.EnumProperty(items = axSym, name = "Axis of Symmetry", default = "0")

    def execute(self, context):
        snapMacro(self, context)
        return {'FINISHED'}

def menu_func(self, context):
    self.layout.operator(snap_macro.bl_idname, text="Snap Macro")

def register():
    bpy.utils.register_module(__name__)
    bpy.types.VIEW3D_MT_snap.append(menu_func)
    bpy.types.WindowManager.sAxis = snap_macro.sAxis

def unregister():
    bpy.utils.unregister_module(__name__)
    bpy.types.VIEW3D_MT_snap.remove(menu_func)
    bpy.types.WindowManager.sAxis

if __name__ == "__main__":
    register()

Put this .py file into your User\AppData\Roaming\Blender Foundation\Blender\2.78\scripts\addons\ directory, or equivelent, depending on OS. Enable in user preferences (searching 'snap' brings it to the top of the list) and save user settings.
What it does:

Adds a macro to the snap menu Shift S
Snaps cursor to selected, with the exception of the axis of symmetry. X is default
Sets pivot point to cursor, since you'll always want to do that
Gives basic operator panel support, allows retroactive change of axis, remembers last axis setting


text:
How move polygons along the normals with Animation nodes?
Im new in animation nodes. And maybe it is very easy question but I cant find solution by myself. I`m trying to make transformation animation and I handled with moving vertices on normals but as I understand polygons have a different approach.

You can use the “Polygon Info” node to access each node's normal and then  pass it through a “Translation Matrix” into the ”“Transform Polygon” node.
The Polygon Info's center output can also be used in calculations regarding the translation distance, e.g. the distance to an Empty or the angle from the torus' center.
BTW: Animation Nodes includes a “Transform Individual Polygons” template which adds the underlying node setup of looping over all polygons and outputting the mesh. You then just need to set up the transformation matrix.


text:
Objects not showing in final render
When I switch to render mode, they show up, and they show when pressing F12, but when clicking the 'Animation' button, nothing shows. If anyone knows how to help, please do.
Edit: I have enabled rendering using the cameras, still nothing.
Edit #2: What the, some how transferring all of the objects from layer 1-2 does the trick. I guess my camera was set up for the second layer even though it was physically in the 1st. Anyone like to explain?
For anyone who's really curious, Here's the file:
Also, it may seem like having the animation length of 1 frame seem bad, but I've done that for other files and they work fine.

Did u mean objects not showing up in final render?

There are many possible reasons, please add a meaningful screenshot or the blend file to the question. Also see: http://blender.stackexchange.com/questions/33787/why-is-part-of-my-model-not-being-rendered,  http://blender.stackexchange.com/questions/18884/cycles-final-render-pitch-black

Okay make sure then the object you are trying to render has render enabled. In the upper right hand part of the screen with all the objects, there should be a camera looking button next to the eye (hide or show). Did you try enabling that?

It doesn't matter on which layer camera is. It does matter which layer is set to be renderable in Render Layers tab. You can have camera on the 1st layer which is set unrenderable and have cube on 2nd renderable layer and the cube will be rendered. And it still could be easier if .blend file / at least screenshots were shown here

It's most likely a Render Layers issue as @MrZak has said. It would be great if you could post your blend file. You should not be getting different output between the F12 single frame render and the Animation render, as they should be using the same pipeline exactly. I'd be very interested to see why that was happening.

check your timeline (your animation length is 1 frame at the moment)

I confirm the problem comes from render layers : all objects on 1st layer, render only 2nd. I just don't understand why F12 render shows something else. I think Mr Zak should answer this :)

There are two possible reasons for this happening.
Reason I - Object Render Disable

You can disable specific objects from being rendered in the Outliner. It is possible you did this without knowing it.

The Camera Button to the right of the Cube Object is disabled, meaning the Cube will not be rendered. Click the camera button to turn on/off rendering.
Reason II - Render Layer Settings

It could be that you have disabled the Render Layer(s) of your object in the render layers.

In the example photo, Scene: layer 1 is active and will preview render in viewport, but since Render: layer 1 is not active, then The objects in Layer 1 will not actually render.
More Render Layer Explanation -
The square buttons below 'Scene:' are the layers that are active and currently shown in 3D viewport. You have these correctly selected if you can see them in the 3D viewport and see them in the render preview.
The buttons below 'Layer:' are the layers that will be rendered. Select every layer that you have objects on to render.
The buttons below 'Mask:' will cause what ever objects on this layer to cut a transparent area through your render.

I deleted the camera and added a new one, everything became visible again.


text:
Combine Filmic Blender and "Standard" Film Emulation
Is it possible to combine the very helpful filmic-blender Color Management with the default Blender Color Management? It helps a lot to light the scenes with the filmic contrast settings, but when it comes to artistic composition and you want to use the benefits of using both troy_s's Settings and the default film emulation, you have to stop your work, close blender, replace the ocio files, restart blender and so on.
Is there a better way to work this out? Is it maybe possible to use the film emulation settings as compositing nodes, similar to a filter in PS or Gimp?
I hope my question is not too stupid. Maybe there is a more elegant workflow to use both, the filmic-blender function and the default film emulation.

Hi cetagon, thanks for the reply. Sorry, but i'm coming from an artistic side, and i don't no about how to manipualte / edit blender Systems files. How can i achive the desired result? What type of editor do i have to use? Thank you !

I think this'll give a bit more info: https://www.youtube.com/watch?v=rj1-TuWsd7Y

Yes yes yes!! Thank you man, this is exactly what i meant ! https://www.youtube.com/watch?v=rj1-TuWsd7Y

but when it comes to artistic composition and you want to use the benefits of using both troy_s's Settings and the default film emulation

I am going to guess that you mean the existing looks. I would advise against them, simply because they are not reliably actually delivering film emulation. That is, the data they were sourced from was actual data, however the way in which they are applied is incorrect. They are effectively random Instagram filters with no meaning. If you mean the ridiculous "Film" transform, it is utterly broken with a horrible label.
That sums up to both groups of transforms as effectively being technically meaningless, and as a result would conflict with the goals and technical output of the filmic-blender set.

you have to stop your work, close blender, replace the ocio files, restart blender and so on.

While true that a restart is required due to how Blender was designed when OCIO was added, it should be pointed out that Blender will respect the OCIO environment variable. Example:
export OCIO=/path/to/config.OCIO

While it is still a pinch point, this technique might make remote rendering etc. easier for some.

Is there a better way to work this out? Is it maybe possible to use the film emulation settings as compositing nodes, similar to a filter in PS or Gimp?

GIMP is broken in many horrible ways that I won't go into, and will remain that way into the foreseeable future. No it is not feasible nor doable without many contortions.
Photoshop as well, while not completely broken as GIMP is, is also strictly a display referred imaging application and makes these sorts of transforms challenging at the base level. It can read some LUT formats, but it is likely complex to list the events here.
What exactly are you hoping for out of the "Film Emulation" set and I can take a look at it.
Again though, I am reluctant to include random knob twiddling in the set, as I am already faced with two design directions (Views vs Looks) that pull against each other.

Hi Troy, thank you for your reply; unfortunately your hint using an environment variable did not help me. I'm not into programming stuff and do not know how to use is.

It is a simpler way of enabling various OCIO configurations. If you give a hint as to what platform you are on perhaps others can help.

Regarding the film emulation i mean the existing looks. I honor that you, quote, "advise against them", but for me they are - at the current state of knowledge - helpful. Some costumers like that style, so i think in terms of commercial purposes it is ok to use them. Is there a better solution? Sorry, i am just at the beginning of the whole topic and need to learn. My idea was to render out images using the advantages of the filmic-blender transform, and do post processing on the basis of this withour changing the ocio manually. Is this possible ? Tank you.

You could save to a display referred output such as a TIFF, and then load the result in the compositor and apply the results. Not sure how it will look. If there are a few particular looks you are using, I could be more specific. Which filmic looks?

Yes, cetagon, that is what i meant. The film looks Canon Optura, Kodak Portra etc. I use them often, but only in a sublte way, means that i use a "clear" render, and combine it with a "flim look" using blend modes. This works - as far a i know - not in Blender, and this was the main intention behind my first question. But the more i learn here, the more it seems to me that this way of getting a special "crisp" and contrast to the image is simply wrong. A Film Emulation is not the same as control image contrast. Am i on the right way?


text:
obj Import .mtl File
Hey I'm struggling with an obj File. I got an obj file and everything seems fine except the Textures are missing. I checked the .mtl file and the .obj file.
I've already looked at Importing OBJ with MTL and Image not working properly
In the .obj File at the start of the File it looks like this after I've replaced an absolute path in mtllib:
# FILE 11740_Baumgartu_Haus_0_3D-Export.obj
mtllib 11740_Baumgartu_Haus_0_3D-Export.mtl
trace_obj 11740_Baumgartu_Haus_0_3D-Export.obj
shadow_obj 11740_Baumgartu_Haus_0_3D-Export.obj

g C211_AUSSENWAND_TR VERPUTZ__GLATT__WEISS

usemtl VERPUTZ__GLATT__WEISS

v -24948.3 -6963.67 8330
v -24903.8 -7471.73 8330
v -24704.6 -7454.3 8330
v -24749 -6946.24 8330
v -25012.6 -7146.54 8570
v -25028 -6970.64 8570
...

and in the mtl file it looks like this:
# FILE:11740_Baumgartu_Haus_0_3D-Export.obj
newmtl VERPUTZ__GLATT__WEISS
Ka 0.916471 0.916471 0.916471
Kd 0.964706 0.964706 0.964706
Ks 0 0 0
illum 2
Ns 100
map_Ka verputz_glatt_weiss.jpg
map_Kd verputz_glatt_weiss.jpg
map_Ks verputz_glatt_weiss.jpg
newmtl 011740_FASSADE_FENSTERBAND
Ka 0.4 0.4 0.376471
Kd 0.633333 0.633333 0.596078
Ks 0.25 0.25 0.25
illum 2
Ns 5
...

The textures are placed in the Folder "11740_Baumgartu_Haus_0_3D-Export_Texturen" inside the Folder where the obj and mtl file is. I have copied the textures directly into the same folder as the mtl and obj aswell.
Can't find what is still missing
In Blender it looks like this:
when importing I have set the search images checkbox

From your screen capture, it seems that the object is not selected/active (it is appearing in orange and not in yellow). Is it the same if it is the active object (RMB on it) ?

Yes I can select one of the objects and it's the same. If i enable Textures in the Viewport shader they are not applied.

I think Blender may show the textures objects even if it is not able to find the textures files. So... if you dont have any textures objects in Blender, this is not a path problem, but a textures objects problem ?

Please, add a screen capture of the object textures once the object is selected as active, in order to see if the textures are defined on it (not the rendering, but the texture data in the texture panel)

http://i.imgur.com/2cubtKA.jpg

OK. The material does not show the image. Could you have a look to the UV/Image editor and check if the textures are there ? If they are not : you'll have to add them. If they are, you'll have to link them to the materials. Sometimes, downloaded files are not perfect...

They do not show up in the UV/Image editor, the model stays gray when rendered. So guess it's manual work from this point on? Thanks for the help!

Probably yes : manual work. But often material and texture names are more or less similar (I hope this is the case for you...).

Please check if the name in the code (mtllib Name.mtl) from the OBJ file is the same as the MTL file name.
If it's not please tweak the code or change the name of the MTL file.
This issue happened to me too when i realised the OBJ file doesn't have the same name
in the code.
If this doesn't work and/or the filename was the same then there
is probably an issue with the code. If the code doesn't match the pictures name's then you schould modify the names.
~Randy


text:
Tracking Long Animation Script
I wrote this script and it will track from one frame to the next.  When I put it in a loop, it no longer works.  I can hit the run key over and over again and it works perfect.  How do I make this script run until final frame?
import bpy
import random

bpy.ops.object.select_all(action='DESELECT')
ctx = bpy.context.copy()
for area in bpy.context.screen.areas:
   if area.type == 'CLIP_EDITOR':
     ctx['area'] = area
     bpy.ops.clip.detect_features(ctx)
     bpy.ops.clip.track_markers(ctx,backwards=False, sequence=False)
     bpy.ops.object.select_all(action='DESELECT')

I have also tried the following and blender only goes forward one frame. I having trouble with changing which frame the script works on and deselecting features.
import bpy
import random
import math

det=0
bpy.ops.object.select_all(action='DESELECT')
ctx = bpy.context.copy()
for numX in range (1, 10):
    bpy.context.scene.frame_set(numX)
    for area in bpy.context.screen.areas:
        if area.type == 'CLIP_EDITOR':
            ctx['area'] = area
            if det==0:
                bpy.ops.clip.detect_features(ctx)
                det=1
            bpy.ops.clip.track_markers(ctx,backwards=False, sequence=False)
            bpy.ops.object.select_all(action='DESELECT')

I guess you just forgot to set the frame: bpy.context.scene.frame_set(YOURFRAMENUMBER) which updates the scene. Why tracking only one frame is a thing?

For script markdown, select your script press {} button or ctrl-K.  For block scripts it indents all one right.  Please edit post.

It's working if sequence argument is set to true. However, what's your goal? Also 'autotracker add-on' might be useful: https://github.com/miikapuustinen/blender_autotracker

How do you set the sequence argument to true? Thanks

Just replace sequence=False with sequence=True @JackFeet (recommend use the @ sign to ping someone)

Thanks for the help @brockmann


text:
How to find out which objects share the same color?
I have created a scene with a lot of objects and I'd like to clean up the project. My question is: how can I find out which objects share the same color?

There are 2 objects that share the same color, 1 object is the cube but where is the second Object?

Do you want to know which objects use the same Material, as shown in the screenshot, or which objects have the same color assigned to, e.g. the Principled BSDF?

Hi @Robert-Gützkow, I will know who Object share the color! I cant find the second Object

You can use the outliner and search for the material name in the display filter.

The indicator for the number of users, as marked with red in your screenshot, is for the users of a material, in this case for the material testfarbe. Please select one object with the material and then try Select > Select Linked > Material. Does that give you the desired result?

negativ :-/ I dont see it

You can use the outliner to filter the scene collection by name.
So you can use it in order to search using the material name.
Once done select all the filtered objects using A in the outliner.

yeahhhhhh :-) thank a lot :-)!!!!!!
I wish you a creative day !!!!!

Consider to accept the answer: https://blender.stackexchange.com/tour @73district

That's an even better approach when you want to know the object's name.

You can press shift+L, then press T, click on materials and check the screen where all objects are listed and find which object is also selected (while being in Object Mode).

:-/ I press crtl+L and choose material but I don´t see it !!!

I think the answer is good but this is Shift+L for me.


text:
Set orthographic view using python?
Is there a python function that sets ortho view such that X and Y axes are visible - the equivalent of numpad 7?
Thanks in advance!

Enable python tooltips in the preferences, then go to View > Viewpoint > Top and wait a second.

Thanks; when I tried the code it threw this error:  RuntimeError: Operator bpy.ops.view3d.view_axis.poll() failed, context is incorrect

Common question: https://blender.stackexchange.com/questions/6101/poll-failed-context-incorrect-example-bpy-ops-view3d-background-image-add

Why wouldn't this work:      for area in bpy.context.screen.areas:
if area.type=='VIEW_3D':
bpy.ops.view3d.view_axis(type='TOP')

You can override the context when calling view_axis() operator.
Blender 3.2+
import bpy
from bpy import context

for area in context.screen.areas:
    if area.type == 'VIEW_3D':
        with context.temp_override(area=area, region=area.regions[-1]):
            bpy.ops.view3d.view_axis(type='TOP')
        break

Blender 2.8+
import bpy
for area in bpy.context.screen.areas:
    if area.type == 'VIEW_3D':
        override = bpy.context.copy()
        override['area'] = area
        bpy.ops.view3d.view_axis(override, type='TOP')
        break


text:
Why the dimension and edge length numbers does not tally when scaling objects?
I created a plane and set its dimensions to 32m x 4.5m. When using the edge length measurement tool, it shows 1m for every edge in the viewport.

Q: Why it doesn't display 32m x 4.5m in the viewport?

This is due to the scale given in object mode. Apply scale Ctrl+A in object mode.

@lemon, thank you. noted.
I'm sorry but i don't understand the logic betwen the extra step...Kindly advice.
Is there any way to automatically make the edge follow the dimension by default?

If you scale in edit mode it will work properly right away.

Does this answer your question? difference between dimension and scale in blender

Related: https://blender.stackexchange.com/questions/47318/why-do-the-measurements-of-this-object-seem-erroneous/47320#47320 and https://blender.stackexchange.com/questions/7298/why-is-it-important-to-apply-transformation-to-an-objects-data

Thank you hive mind. I have learnt a lot from the link you provided. Now i understand.


text:
How to batch export all UV layouts for multiple objects?
I'd like to export UV sets for several objects which I need to be separated. Imagine one layer per object on a PSD file... right now im exporting the maps one by one but would like to try writing a script to at least do this in batch.
I've tried the answer by @HikariTW and the code almost works, but not properly. I've managed to solve a few errors, but the script is not working as intended.
It gets the active object, adds another one from the list and saves both objects UV's. Ideally the script should set one object from one collection to active, set it to Edit Mode, export it's uv map using the object name as the image name, set it back to Object Mode, select next and iterate.
I've tried to write the code I need from scratch using the suggested one as a reference but it's way over me:
import bpy
import os

# You should change this varibale in "here" to match your own directory path
# use '/' or '\\' for hirecacy
target_dir = "D:/directory/"

selObj = []

for obj in bpy.context.selected_objects:
 selObj.append(obj.name)

bpy.ops.object.select_all(action='TOGGLE')

i=0
while i < len(selObj):
#line 18 does not work (AttributeError: bpy_prop_collection: attribute "active" not found) so i've updated it to 19-20
    #bpy.context.scene.objects.active = bpy.context.scene.objects[selObj[i]]
    obj = bpy.context.window.scene.objects[0]
    bpy.context.view_layer.objects.active = obj
    bpy.ops.object.mode_set(mode="EDIT")
    bpy.ops.mesh.select_all(action='TOGGLE')
    bpy.ops.mesh.select_all(action='TOGGLE')
#no need for line 25 since objects have already been unwrapped
    #bpy.ops.uv.smart_project(angle_limit=66.0, island_margin=0.0, user_area_weight=0.0)
    full_file_name=target_dir + bpy.data.objects[selObj[i]].name

    # This code detected whether target_dir exist, if not, then create it
    dirname = os.path.dirname(full_file_name)
    if not os.path.exists(dirname):
        os.makedirs(dirname)

    bpy.ops.uv.export_layout(filepath=full_file_name, mode='PNG', size=(1024, 1024), opacity=0.6)
    bpy.ops.object.mode_set(mode="OBJECT")
    bpy.ops.object.select_all(action='TOGGLE')
    i+=1

Q: How can I make that work to export the maps for all objects?

Welcome Rodrigo! Sure, that's possible. What exactly you can not access? I guess you'd like to get the python tooltips right? Go to 'User Preferences > Interface' and enable 'python tooltips' as well as 'Developer Extras'. Also, it seems there already is an answer to this over here: Python: How to Export All the UV Layouts in Blender. Suggest try the script and report back by editing your question, please read: https://blender.stackexchange.com/help/how-to-ask


text:
Why is the grease pencil on this specific area didn't render like the rest of the outlines?
Why is the grease pencil on the bottles area didn't render like the rest of the outlines? For additional info, those lines that didn't render properly were drawn while in front view while the rest is with the camera view toggled on.
This is the rendered image.

This is the viewport rendered image.

Here are the settings when I was working on this:

Are the labels separate GP object or a separate layer in a GP object? Check Strokes > Stroke Depth Order in the Grease Pencil Data properties.

yes, it's separated. the stroke depth order is in 2D layers. Tried it in 3D location but it got worse lol. I just went with having it exported through viewport render image. Is it the same? Anyways, thanks for answering!

I didn't see any difference in the quality of the renders, so that is a good and fast workaround. It is a good idea, if you can, to share a portion of the scene file with the problematic area. That may help immensely in finding the solution.

Is this what you're referring to? https://imgur.com/a/Qq6ZI6e
Sorry I'm still pretty new in Blender.


text:
Adding subdivisions without disrupting details
It's my first time asking a question here and I hope anyone could help.
I've recently watched a video about modeling a super simple object, starting with very low poly mesh in order to achieve the block out shape and some major details. As the mesh progresses the tutor would increase the number of edges in order to get more geometry for finer details. The software he was using was Maya and what he did seemed like a piece of cake. Since I use Blender I tried the same steps but it didn't work out as expected. If I went for edit mode>subdivide>smoothness=0, the overall mesh would be very lumpy but the detail would come out nice. If I did edit mode>subdivide>smoothness=1, it would be the other way around.
So, my question is: is there a way of adding more geometry without sacrificing any details already made?
Thank you!

What does it give if you apply a Subdivision Surface modifier instead?

SubD modifier does work. Problem is that geometry gets too dense too quick. The other drawback is that newly created faces are non workable unless the modifier has been applied.


text:
How to switch left and right skeleton position?
I just started using blender. For some unknown reason, the skeleton become mirrored where all the left bone was placed to right,, like their were all switch places, rotating "arm_upper_R" makes the object Left arm move. still working but theyre in the wrong places, how to fix this??

look at the top right of the 3D View, you must have the X symmetry option activated

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


text:
Permanent Material Overrides to Linked Files When Reloading
I am building a neighborhood model from my home town all based on old photos. There will probably be around 100 highly detailed buildings and street furniture.
Match photo on Sketchup is essential to my modeling, and would like to continue using it. To combine all the buildings, I was going to export the Sketchup files and import them into Blender, then link those files into a master Blender file. I anticipate actively updating each file as I find more information, so having a live link from the individual models to the master file is important.
What I am worried about is losing all my material settings. If I link a building, set all the materials in Blender, find I made a mistake, correct it on Sketchup, then go through the process of reloading it into Blender, it looks like I will lose a considerable amount of time redoing all the materials.
What would be a better workflow here? I am open to using other programs to combine all the files. The important thing is to keep all the links/references live.

What is the export/import file format?  obj?  fbx?   Can you export or import a subset of only the objects you needed to change?

I was going to do DAE.
Regardless of what I do to the individual building, as soon as I would reload the linked file, I would lose my overrides.


text:
How to UV map complicated bevels
I am trying to UV map a wing but whenever I apply the texture, it completely bugs out. This is the second time I've modeled it so its not like the original file was corrupted or anything. Scale is at 1,1,1. As you can see from the pictures, I used bevels to make the shape. Any help is appreciated. Thanks.

try applying those bevels first

I already tried changing the bevel order but the only way it gets that shape is with that order.

i meant applying the modifiers from top to bottom, not changing order of them

I don't know what you mean. I'm not so experienced with Blender.

In my test file that problem doesn't occour: http://imgur.com/xr03CNo. Maybe you have particular setting in your modifiers/geometry. Could you upload it? Anyway here's mine: http://blend-exchange.giantcowfilms.com/b/466/

Here is the file https://www.dropbox.com/s/vzy33ds6k89pzi2/Wing3x3%202.blend?dl=0

Unwrap final geometry, or split faces, or mark additional seams
You are unwrapped a model, which means to assign to every face (5 in your case) a portion of the UV space.
By beveling the edges, your geometry doesn't have still 5 faces, but a bit more. The UV informations about those new faces are coming from an interpolations of the previous faces UV, so it may happen that not all of them are corrects (expecially when your UV is made by disjoined pieces) as in you case:

In addition your geometry has some caharecteristics that make the effect come out. If it has been more compact on the X axis you would not have such distortion.

Solutions:

Apply all modifers ( or converto to mesh your mesh... with Alt+C, or at least the ones that have more impact on the geometry, and THAN unwrap your geometry (Suggested if suitable)

If you need to keep the modifiers in your workflow you can try to disconnect the triangular faces. With vertex disjoined there will surely be no wrong interpolation between the triangular faces and the others (but you have to add additional vertex bevel modifiers to smooth the spikes..)

Mark all edge as seams. In this way Blender will consider each face separately and it will not occour unexpected interpolation and your topology will remain clean. Anyway your UVs islands may result slightely overlapped or disjoined, so you'll have to re-unwrap in anycase, but at least you can "preview" the UV correctly without applying modifiers.

I just wanted to follow up, this worked exactly how I needed and made some of my other models better as well. Thanks again for the help :)

Third way, how?

Could you clarify what are you referring to @modernator? How to mark edges as seams?


text:
Jagged edges when using Glare in Compositor
I have designed this jewel:

I am using Compositing nodes for the final render, to add a glare effect, as such:

But the result is that some of the edges of the golden shape are irregular where the glare is most present:

I have tried to change the settings in the Compositing nodes, which didn't do anything, and I can't seem to find a way to make the edges as sharp as they should be.

Can you upload your .blend file to Blend Exchange?

@ShadyPuck I just added the .blend

@cegaton yes, I played around with the settings and never really got anything satisfying in terms of sharpness

@fabriced I must confess I don't really see anything obviously amiss in both circled regions.. What exactly are you looking for in terms of "sharpness"?

Unrelated, but I thought I'd mention that the alpha-over node in your setup isn't needed. If you want to mix between the original image and the glareified version, the mix setting on the glare node can be adjusted; -1 is the original unmodified input, 0 is the glare + input, and 1 is just the glare (and everything in-between is a mix).

Changing the setting from Medium to High solved the problem! Please @cegaton make this an answer so I can accept it :)

@cegaton true, maybe your suggestion became a more obvious answer after removing the useless "Alpha Over" Node, as suggested by gandalf3 after I said changing settings didn't work. I can write an answer, sorry if your feelings were hurt, your contributions have been very helpful across the site.

Combining cegaton and gandalf3's comments, I removed the useless Alpha Over node:

then switched the setting for the Glare node to "High":

This resolved the pixelation / jagged diagonal lines I was seeing:


text:
How to "ground" a character's legs?
I would like my character to stand on one leg.
On pose one it would be standing on the ground:

And on pose two it would be standing on its left leg kind of like this:

but when I select all the bones except the leg and then rotate the whole shape rotates and the leg doesn't seem grounded on the floor anymore:

I believe it has to do with parenting the bones? It's hard for me to know what to look for to solve this and I'm just a beginner with rigging. I've tried all sorts of things in the Bone Constraints panel but couldn't find one that did this. I also tried playing with weight painting but I think it messed things up more than anything else.

What are you looking for is called Inverse Kinematics (IK):
In edit mode extrude a new bone from the leg (I called it "Foot On Ground") which will be the target of the IK Chain. Set it to "non deform" (uncheck the relative button in the bone properties panel) and parent it to the chest bone.
In pose mode select the leg bone and assign her an IK constraint.
In the empty boxes select "Armature" (it's the name of your armature) and "Foot On Ground". Set the IK chain lenght to 2.
Now the IK chain, 2 bones long (leg and hip Left) will always "point" to the target bone (Foot on ground).

I suggest you to copy some simple estabilished rigs before building your own, trying to understand the basic concepts. Search for Nathan Vegdahl rigging serie (free on Youtube) for an amazing advanced rigging course, from scratch to humane rigging.

Thanks! Also, switching the Pivot Center to 3D cursor helped :P


text:
How do I reset my UV window?
The object in that window are not showing up whereas it is right in 3D View:

Q: How do I reset my UV window to display the object properties?

Hello :). What do you mean by "The objects in that window are not right while in the other viewport are right"? It's not very clear from the screenshot :).

@JachymMichal I have modeled a doughnut and a coffee cup but I can find/see (they are not displayed as in the layout window) in the UV window. On the screenshot attached, in the right viewport, there is only some kind of a empty ''shadow'' in the 3D space.

hello, please share your file: https://blend-exchange.giantcowfilms.com/

@JachymMichal hello, did you check the file I just uploaded? What was the issue?

Hello @David :). You need to share the link the blend-exchange site generates after upload. Otherwise we can't access your file :)

 @JachymMichal Is that it?

That was it @Daniel. Answer is up now :).

Thank you! :) @JachymMichal

If the answer solved your problem, please mark it as accepted ✓. To keep the site nice and tidy :)

It looks like a bug in Workspaces.
Simply create a new UV workspace an then it should work.
+ > General > UV Editing


text:
Why my highlights getting lost when re-importing a rendering into the compositor?
I noticed that I'm loosing colour information in the highlights after exporting and importing pngs from Blender. I know that the compositor works with linear space but something gets lost when saving to png.
Here is what I do:

Render my image and look at it in compositor, all highlights preserved
Save the image as png and look at the png with an image viewer, all highlights preserved
Use an Image node in compositor and look at png, highlights lost
Safe the image from the node to png, highlights still lost

So there is something going on while importing/reading the file. I have checked "View as Render" in the image nodes properties. I use Blender 2.90.0
Any ideas?

Are you saving png with an alpha layer ?

Never use png, it is not a good format to store images that are meant for compositing or further manipulation, plus is a format that does not deal with alpha channels correctly.
Use EXR. Think of EXR as a way to save your render layers intact, as blender generated them.
The compositor does works using scene referred, unlimited linear data (there is no such thing as "linar space"). If you want to save images to be composited later or do any kind of post processing you need to keep the rendered images as scene referred, comopositing operations work better if the data is in a linear scale.
PNG is a display referred format, not only has a limit in the sense that it cannot store values larger than 1, but most likely the image information has gone through a display transform, set in the color management section of blender, which applies a transfer function (also known as a "gamma curve"), so the data is no longer linear.
If you "must" use png, or any other display referred format, that has an image that is meant to be viewed as sRGB, then you need to set the color management view to sRGB when you import it back to blender, so that it is interpreted correctly using "view as rendered. Otherwise the information will be processed using "filmic", which is the default color transform.
Images displayed in a different color space will always look wrong
Another way to understand the issue:
When you import an image into the compositor, you have to let blender know what kind of color space the image is using, so that blender applies an inverse view transform to "linarize" the data, then that it can be composited correctly. If the data comes from images in display referred formats, and the color space in blender is set to filmic, then the values are too low, and what used to be white in the picture(1) will only be gray, as filmic expects much larger values for white (aproximately 16.19). If you set the view transform to sRGB, then white will be set to 1 again...
read:
Render with a wider dynamic range in cycles to produce photorealistic looking images
and
Why We Bother With Linear and Nonlinear Encodings At All?

Ah wow, its very confusing to me that color management in in the render settings tab and still effects the compositor. Thanks for making things clear to me, i will need to use .exr in the future or keep in mind to switch color management when doing png stuff

Color management is meant to be able to control all output (3d, compositor and the terrible VSE). The only output that by design skips all color transforms is EXR.


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How to prevent Blender from crashing when running out of memory?
I'm waiting for like 5 minutes for a render to start, nothing happens (Blender 2.90.1) and Blender is crashing in the end. I already tried to render the project using Blender 2.83.8 but I'm getting the same issue. As you can see from the screenshot, I'm running out of memory since I only have 16gb RAM and it's showing me that blender is using 20.34gb. The viewport is fine however, I can see the image resolving and everything...

Q: Is there any chance to render my image although I don't have enough memory?

Welcome to Blender Stack Exchange, I believe the crash should be reported as a bug, rather than posted as a question, my advice is to make sure that your file is optimized to suit the specs of your machine, adding more information would help too, how many vertices do you have? what render engine are you using? ... etc.

i have never used this site before that why i didn't know where to post it , I'm sorry tho , i have 155,769 vertices and the render engine is cycels as i mentioned i hope this information could help you to find a solution for me

Related: https://blender.stackexchange.com/questions/76068/cycles-cuda-out-of-memory-on-final-render-but-not-on-preview and https://blender.stackexchange.com/questions/84466/blender-error-out-of-memory

No problem @ilyesbouabdelli , you can read more about BSE in the meta, concerning the crashing issue, as I mentioned, try first to update the drivers for your graphics card, if that doesn't work, report a bug from within blender, in the help menu

@Georges Crashes caused by running out of memory are not a bug and should not be reported on the bug tracker. Optimizing the scene is the way to go, Blender has to work within the limits the hardware and operating system sets.

@RobertGützkow check the OB comment, he has 155.769 vertices, I believe memory is very unlikely to be the issue, on the other hand, I had similar issues before, that turned out to be because the graphics card drivers are outdated, which is what I suggested to be done first

@Georges They have explicitly stated that they have 16 GB RAM and 20.34 GB are being used, which is also shown in the screenshot. So it's clearly running out of memory and Windows can't compensate by using a page file on disk. Geometry is not the only part that require memory, for instance large textures could also contribute to this.

@RobertGützkow I guess you're right.

If you are out of memory, the only solutions are to install more RAM in the computer, or to make the paging file (virtual memory stored on disk) in the OS larger.
Or work in scenes that do not exceed the resources available in your computer. Don't abuse the number of particles, use instances instead of duplicates, use modifiers and set subdivision surface to low values Blender render crash when using subsurf modifiers.

Solution for Linux system: I had a similar problem. I bought additional memory, 64GB, but was not enough. What I found out that if you are on a Linux system, you can increase swap space, for instance to additional 64GB on your Nvme drive. Once the RAM memory starts to run out, the swap space will be used. This way your render will not crash.


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Why eevee renders reflective objects in black and cycles does not?
Eevee renders objects in black, while Cycles renders as expected. HDR is present and lights are in the scene. I'm not using any textures. Thanks for any ideas.

Q: Why my reflective object is pitch black in eevee?

Try enabling screen-space reflections in EEVEE.

Enabling screen-space reflections in eevee did not solve the issue. Thanks.

It is hard to find out what is causing the issue here. Can you provide the file?

Model behaves the same (eevee has black text, cycles has correct shiny text) whether transparency is set or not.

Works correctly for me. check your Graphics Drivers, make sure you have the latest, also try to Delete Blender and install again

Are you saying that the model, as loaded, doesn't have black text when rendered in Eevee (shiny in Cycles)?  Graphics drivers are current on both machines that show it as black. I'm already using a fresh B2.83.1, as B2.83.3 crashes frequently.

Works as expected... How this is different to Why is my material rendering black? Please edit your original question using the edit button next time, Thanks. How this site works: https://blender.stackexchange.com/tour How to ask a good question: https://blender.stackexchange.com/help/how-to-ask

This is different because this is describing a problem only with rendering in Eevee, since Cycles renders the material properly. Already been pinged for "having a discussion in the comments", so since this is a different problem, I made a new topic.

Have you tried the file on another machine in the meantime? Make sure your GPU meets the minimum requirements: https://www.blender.org/download/requirements/ Again working fine here, even on my low-end machine (i5, integrated graphics, linux). If you are on windows try a linux or report the issue as suggested before.

I have discovered that the problem discussed here, as well as other recent rendering posts, may be linked to a video issue related to recent updates.
After duplicating the issues on three computers, all of which meet the video requirements as stated by Blender documentation, I began trying several recent Blender versions. All exhibited rendering issues except Bv2.81.
Thanks to all who helped.

Certain hardware... real issue is: if no one with that graphics card, files a bug report it never get fixed.

Navigate to the Render Properties > Screen space reflections > enable refraction.
I hope this works.

This didn't work (previously suggested above). Thanks though.


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Why is my rotation reversed in 2.91?
For some reason, now that I've installed 2.91, all of my rotations are reversed. If I press R and type a number, it goes counter-clockwise. The angles in the Properties Panel N are also flipped. When I try to rotate and snap to a vertex, it's like the part I'm rotating gets mirrored. I've tried to show all of thse problems in this video: https://www.youtube.com/watch?v=hFd6MtIycpE

Because, to be blunt, the devs frigging broke the behaviour of the rotate operator AGAIN. A fix has been committed so it should be reverted in the next hot fix. https://developer.blender.org/rBf9e994d0f463abb87761591e30c47a9613be6cca