Viewport preview for Cycles 'Generated' texture coordinates fails for Bezier Curve Objects
Closed, ArchivedPublic

Description

System Information
Windows 7 64 Bits, Intel Core i7 2600K, GTX 580 + GTX980Ti

Blender Version
Broken: 2.77, 279
Worked: Never as far as I noticed

Short description of error
Viewport preview for 'Generated' type of texture coordinates seems broken for Bezier curve objects only
This may well be a limitation of the current system and not a bug per-se

Exact steps for others to reproduce the error
Create a new Cycles node material and assign it to both any bezier curve and mesh object simultaneously
Add a new Input >Z Texture Coodinates node and any type of texture (procedural or image based)
Connect the Generated output socket of the Texture Coodinates either directly to the shader color or feed it as texture coodinates to the texture.
Both will preview fine in the viewport for the mesh object, but fail on the bezier curve

Note that both render fine with cycles, this is only a OpenGL viewport issue, and might as well just be a limitation of the current system, rather than a bug, I don't know enough to tell.

Details

Type
Bug
matali23 (matali23) triaged this task as Incomplete priority.Jun 28 2017, 9:04 AM

please attach a blend

Oh, sorry, here you go.

To reproduce the issue just set the Viewport Shading Mode to Material you will notice the only object in the scene has this pink-ish hue.
If you select the Bezier Curve and convert it to mesh with Alt+C > Mesh From Curve, the coordinates will display correctly as a gradient.

Let me know if you need anything else.

Bastien Montagne (mont29) raised the priority of this task from Incomplete to Normal.

@Sergey Sharybin (sergey) might want to have a look at this one?

Sergey Sharybin (sergey) closed this task as Archived.Aug 23 2017, 4:10 PM
Sergey Sharybin (sergey) claimed this task.

The issue here is that Generated coordinates for curves are stored differently than for meshes and currently drawing is mainly built around meshes. It might be possible to extend existing GPU drawing or to add same CustomData layers support for display-lists used by curves, but this isn't really considered a bug but rather a design limitation.

Keep in mind, whole drawing system is being changed in Blender 2.8, so rather solve that in there.

I've added a not in our TODO list about this issue: https://wiki.blender.org/index.php/Dev:Source/Development/Todo/Editors#3D_View:_Drawing

So thanks for the report, but you'd need to give us some time to make it a really nice viewport in 2.8!

Yes I understand, I feared as much. May this eventually work well for 2.8 then.

Thanks for the enlightening response.