Smooth Shading not working with Cycles #42082

New Issue

Steve Ernst · 2014-10-05T07:12:11+02:00

Steve Ernst commented

2014-10-05 07:12:11 +02:00

System Information
Operating system and graphics card - Windows 7, Nvidia GeForce GTX 650

Blender Version
Broken: 2.72 95182d1
Worked: 2.71, but when using "true" displacement with Cycles, issue arose.

Setting an object to smooth shading works in solid view, but switching to rendered view reveals faces. I observed this problem in the previous version when experimenting with True displacement in Cycles, but assumed it was an issue with that feature being still in development. Now even when using default 'bump' displacement in rendered view, individual faces are evident.

Create UV sphere, add subsurf modifier at level 2, switch to smooth shading, go to rendered view.
Smooth_shading_problem.blend

**System Information** Operating system and graphics card - Windows 7, Nvidia GeForce GTX 650 **Blender Version** Broken: 2.72 95182d1 Worked: 2.71, but when using "true" displacement with Cycles, issue arose. Setting an object to smooth shading works in solid view, but switching to rendered view reveals faces. I observed this problem in the previous version when experimenting with True displacement in Cycles, but assumed it was an issue with that feature being still in development. Now even when using default 'bump' displacement in rendered view, individual faces are evident. Create UV sphere, add subsurf modifier at level 2, switch to smooth shading, go to rendered view. [Smooth_shading_problem.blend](https://archive.blender.org/developer/F115032/Smooth_shading_problem.blend)

Steve Ernst commented

2014-10-05 07:12:11 +02:00

Changed status to: 'Open'

Steve Ernst commented

2014-10-05 07:12:11 +02:00

Added subscriber: @steveernst117

Bastien Montagne commented

2014-10-05 09:23:51 +02:00

Added subscriber: @mont29

Bastien Montagne commented

2014-10-05 09:23:51 +02:00

I cannot confirm that here (linux64), either with official 2.72 nor with latest master. CPU render only though, are you using GPU?

Steve Ernst commented

2014-10-05 15:57:33 +02:00

Using GPU. Also, I was able to further refine the circumstances of the problem...apparently it has something to do with using a normal map texture connected to a normal map node connected to a shader node. If the normal map node is disconnected, or its strength set to 0, the visible faces go away.

Sergey Sharybin was assigned by Bastien Montagne

2014-10-05 18:44:31 +02:00

Bastien Montagne commented

2014-10-05 18:44:31 +02:00

Sounds like a GPU-only issue then…

Sergey Sharybin commented

2014-10-07 15:53:46 +02:00

I can not reproduce the issue here, perhaps the images are essential for this. Please pack them in.

Also,

Does using Supported feature set helps?
Does using Static BVH makes any difference?

I can not reproduce the issue here, perhaps the images are essential for this. Please pack them in. Also, - Does using Supported feature set helps? - Does using Static BVH makes any difference?

Steve Ernst commented

2014-10-08 00:11:41 +02:00

Here's the new .blend. I used the 'pack all into .blend' option...let me know if something didn't go through.

No, using Supported and Static BVH changes nothing. Again, it seems to just be an issue with normal mapping. Changing the value of the normal map doesn't fix it until it's set to 0, then the faces disappear and look smooth again. Also, this happens in CPU rendering as well, so not just a GPU issue.

Here's the new .blend. I used the 'pack all into .blend' option...let me know if something didn't go through. No, using Supported and Static BVH changes nothing. Again, it seems to just be an issue with normal mapping. Changing the value of the normal map doesn't fix it until it's set to 0, then the faces disappear and look smooth again. Also, this happens in CPU rendering as well, so not just a GPU issue.

Steve Ernst commented

2014-10-08 00:13:37 +02:00

Hmm...apparently the file didn't go through. Let's try this again.Smooth_shading_problem_01.blend

Hmm...apparently the file didn't go through. Let's try this again.[Smooth_shading_problem_01.blend](https://archive.blender.org/developer/F115424/Smooth_shading_problem_01.blend)

step-ani-motion commented

2014-10-08 10:03:10 +02:00

Added subscriber: @STEP-ANI-MOTION

step-ani-motion commented

2014-10-08 10:27:41 +02:00

Hey! I also have this issue.

Here are some screenshots

I'm on:
Win7 64
Quadro 4000 (gl), GTX 690 (render), Driver 344.11

Hope this helps.

Hey! I also have this issue. Here are some screenshots ![cycles_smooth_shade.png](https://archive.blender.org/developer/F115449/cycles_smooth_shade.png) ![cycles_smooth_shade_02.png](https://archive.blender.org/developer/F115451/cycles_smooth_shade_02.png) ![cycles_smooth_shade_03.png](https://archive.blender.org/developer/F115453/cycles_smooth_shade_03.png) I'm on: Win7 64 Quadro 4000 (gl), GTX 690 (render), Driver 344.11 Hope this helps.

Thomas Dinges commented

2014-10-08 10:52:01 +02:00

Added subscriber: @ThomasDinges

Thomas Dinges commented

2014-10-08 10:52:01 +02:00

This is just the Terminator issue. Subdivide your geometry further to fix it.

Thomas Dinges commented

2014-10-09 11:53:36 +02:00

Changed status from 'Open' to: 'Archived'

Thomas Dinges closed this issue

2014-10-09 11:53:36 +02:00

Steve Ernst commented

2014-10-09 13:22:01 +02:00

Well yes, that would be an obvious solution....but the point of 'smooth shading' is to make it look smoother without the need for more geometry. Which, again, works perfectly until a normal map is applied. I'm sure I don't need to remind anybody that adding buttloads of faces to a simple object whenever I want to use a normal map is less than ideal. Any other useful advice?

Sergey Sharybin commented

2014-10-10 09:32:46 +02:00

It's not a termination issue. It's either a tangent space calculation issue (which i don't think has a huge probability of being faulty) or it's just a precision issue of your tangent normal map. Try using 16bit PNG at least, float and half-float EXR would be even better.

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Smooth Shading not working with Cycles #42082