Missing smooth (face-varying) UV subdivision. #49431

New Issue

Yegor · 2016-09-23T02:58:02+02:00

Yegor commented

2016-09-23 02:58:02 +02:00

System Information
Debian testing, Nvidia GTX 780

Blender Version
Broken: 2.78 RC2

Short description of error
Adaptive subdiv tears mesh apart along uv seams even if adaptive is unchecked.
There are four phases:

Adaptive enabled and displacement set to both -> huge tearing
Adaptive enabled and displacement set to both -> huge tearing (differs a bit)
Adaptive disabled and displacement set to both -> thin tearing and small holes in some uv corners
Adaptive disabled and displacement set to true -> no tearing and bigger holes in some uv corners

Exact steps for others to reproduce the error
Open the file and hit render in four different conditions.

I think the problem is in the difference in UV smoothing while baking the map and while rendering.
When you bake a displacement map, you are using the only available method for UV smoothing - vertex with valence of 2 is considered a corner and not being smoothed, while all the other valences ARE being smoothed. And I consider it the rightest way to smooth UV, by the way.
On the other hand, when we render, we use one of the OpenSubdiv's method for UV smoothing and it's hidden under the hood. You guys tell me which method it is.
For example, Renderman, Maya, Mudbox, etc have the option to choose the UV subdivision method, which leads to a ton of problems (on our studio, for example), by the way, when you need to synchronize the smoothing method while sculpting and while rendering. But it would be very nice to have this kind of option to choose in Blender.

I hope i'm not mistaken.

Thank you.

subdiv_test.blend

**System Information** Debian testing, Nvidia GTX 780 **Blender Version** Broken: 2.78 RC2 **Short description of error** Adaptive subdiv tears mesh apart along uv seams even if adaptive is unchecked. There are four phases: 1) Adaptive enabled and displacement set to both -> huge tearing 2) Adaptive enabled and displacement set to both -> huge tearing (differs a bit) 3) Adaptive disabled and displacement set to both -> thin tearing and small holes in some uv corners 4) Adaptive disabled and displacement set to true -> no tearing and bigger holes in some uv corners **Exact steps for others to reproduce the error** Open the file and hit render in four different conditions. I think the problem is in the difference in UV smoothing while baking the map and while rendering. When you bake a displacement map, you are using the only available method for UV smoothing - vertex with valence of 2 is considered a corner and not being smoothed, while all the other valences ARE being smoothed. And I consider it the rightest way to smooth UV, by the way. On the other hand, when we render, we use one of the OpenSubdiv's method for UV smoothing and it's hidden under the hood. You guys tell me which method it is. For example, Renderman, Maya, Mudbox, etc have the option to choose the UV subdivision method, which leads to a ton of problems (on our studio, for example), by the way, when you need to synchronize the smoothing method while sculpting and while rendering. But it would be very nice to have this kind of option to choose in Blender. I hope i'm not mistaken. Thank you. |![adaptive_displacement_both.png](https://archive.blender.org/developer/F366502/adaptive_displacement_both.png)|![no_adaptive_displacement_true.png](https://archive.blender.org/developer/F366503/no_adaptive_displacement_true.png)| | -- | -- | |![no_adaptive_displacement_both.png](https://archive.blender.org/developer/F366504/no_adaptive_displacement_both.png)|![adaptive_displacement_true.png](https://archive.blender.org/developer/F366505/adaptive_displacement_true.png)| | -- | -- | [subdiv_test.blend](https://archive.blender.org/developer/F366510/subdiv_test.blend)

Yegor commented

2016-09-23 02:58:02 +02:00

Changed status to: 'Open'

Yegor commented

2016-09-23 02:58:02 +02:00

Added subscriber: @YegorSmirnov

blender-admin commented

2016-09-23 02:58:02 +02:00

#49488 was marked as duplicate of this issue

Mai Lavelle was assigned by Aaron Carlisle

2016-09-23 03:12:00 +02:00

Yegor commented

2016-09-23 18:20:22 +02:00

Here's one more evidence.
It looks like adaptive subdiv doesn't smooth uv's borders at all. The texture has a perfect white circle and it should look like on the left cylinder.

Here's one more evidence. It looks like adaptive subdiv doesn't smooth uv's borders at all. The texture has a perfect white circle and it should look like on the left cylinder.![uv_smooth_test_render.png](https://archive.blender.org/developer/F366833/uv_smooth_test_render.png)

Ronny G commented

2016-09-23 19:25:56 +02:00

Added subscriber: @nudelZ

Ronny G commented

2016-09-23 19:25:56 +02:00

subdivide uvs is not supported at the moment (thats why its grayed out :))

Yegor commented

2016-09-23 19:36:17 +02:00

Oh, that's a shame. It makes adaptive subdiv useless, unless you don't use uv subdivision across all of your objects while sculpting and texturing, which is not a common practice. Or you just don't have uv seams

Brecht Van Lommel commented

2016-09-25 02:03:17 +02:00

Added subscriber: @brecht

Brecht Van Lommel commented

2016-09-25 02:03:17 +02:00

Smooth UV subdivision is indeed missing still. Of course it's important but that's why this feature is marked Experimental, it's unfinished.

Yegor commented

2016-09-25 02:12:22 +02:00

It surely is experimental, but it's a huge game changer, and I just can't wait to use it throughout my projects. That's why i'm testing and reporting issues so bad:) And many people already treat it as a killer feature and make reviews, such as Andrew Price.
Anyways, thank you for your hard work!

It surely is experimental, but it's a huge game changer, and I just can't wait to use it throughout my projects. That's why i'm testing and reporting issues so bad:) And many people already treat it as a killer feature and make reviews, such as Andrew Price. Anyways, thank you for your hard work!

Brecht Van Lommel commented

2016-11-12 20:33:27 +01:00

Added subscribers: @Mordicus, @MaiLavelle, @mont29

Lionel Mochamps commented

2017-01-27 09:06:09 +01:00

Hi, I don't know what is the status of this task but I will join Yegor in saying that this feature would have a huge positive impact on my workflow. I would even qualify this as paramount, it alone would open a world of new possibilities in my work. I do archeological reconstruction and restitution and the ability to use a uv displacement map with adaptative subdivision would allow an unprecedented level of detail across the entire model without worrying too much about performance. I can't wait to see this feature fixed and implemented! Thanks for your consideration.

Emir Sinan Gürlek commented

2018-05-31 20:47:25 +02:00

Added subscriber: @filibis

Daniel Mikolajcak commented

2018-08-13 19:12:06 +02:00

Added subscriber: @dmiko

Daniel Mikolajcak commented

2018-08-13 19:12:06 +02:00

Hi guys,
some observations and wishes for microdisplacement.

I wish you could have continuous displacement even in flat shading, especially for quick set ups of walls etc. (I think Vray has this option)
the only workflow that does not rip geometry is smooth shading, subdivision to avoid artefacts, and box uv projection (3.)
UV unwrapping produces beautiful edges (4.) unless you place a UV seam which rips the geometry, This should be fixed easily since box projection (3.) projects different image portion on cube face too, but does not rip the geometry.

Cheers,
Daniel

Hi guys, some observations and wishes for microdisplacement. ![Displacement.jpg](https://archive.blender.org/developer/F4215943/Displacement.jpg) - I wish you could have continuous displacement even in flat shading, especially for quick set ups of walls etc. (I think Vray has this option) - the only workflow that does not rip geometry is smooth shading, subdivision to avoid artefacts, and box uv projection (3.) - UV unwrapping produces beautiful edges (4.) unless you place a UV seam which rips the geometry, This should be fixed easily since box projection (3.) projects different image portion on cube face too, but does not rip the geometry. Cheers, Daniel

Mai Lavelle changed title from ~~Adaptive subdiv tears mesh apart along uv seams~~ to Missing smooth (face-varying) UV subdivision.

2018-09-14 04:00:52 +02:00

Yegor commented

2019-09-01 23:39:51 +02:00

I've tried it in 2.81 and seems like this bug is gone. Is it?

Emir Sinan Gürlek commented

2019-09-02 01:07:35 +02:00

I think yes @YegorSmirnov . Check this: Cycles: Stitching of subdivided and displaced meshes

I think yes @YegorSmirnov . Check this: [Cycles: Stitching of subdivided and displaced meshes ](https://developer.blender.org/rB697fd86506fd0caaa41e2fbf0463b5229d09251e)

Philipp Oeser commented

2021-03-23 15:21:57 +01:00

Added subscriber: @lichtwerk