Tessellation Bug Report

[xKosta]

Hi Amplify,
I think I just run into a Bug by using Tessellation and Vertex Colors. Please visit the attached image. There you will see that I am using the vertex color Node to apply the tessellation only on specific parts. If I compile this with Amplify Shader Editor, I get an error message and a pink object, by correcting the variable Name into v0. The shader gets compiled and the desired effect is visible.

By the way, I had several issues enabling tessellation, is there any kind of known issues there? Cause I think I can send you a whole list of Bugs or Problems to that Feature. Right now I am not sure if I can identify them so clearly.

Using current Version of Amplify and Unity 2017.1

Thanks
Konstantin

[Amplify_Borba]

Hello Konstantin, thank you for getting in touch!

Judging by the code, it seems that you are attempting to connect the Vertex Color data to the Tessellation Input, which is not supported since that input is reserved for specific tessellation parameter control.

Sadly, you cannot define the tessellation amount per-area, the current tessellation implementation provides Distance-Based, Fixed, Edge Length and Edge Length Cull.

Can you share your actual shader so that we can confirm that the problem is caused by the reasons mentioned above?

Looking forward to your reply!

[xKosta]

Thanks for the fast response, I took a screenshot of the shader, but it is like you mentioned. If it is not supported, I will look for a different approach.

[Amplify_Borba]

I wish we could help but, given that's a limitation of the technique itself, there's nothing we can recommend.

Could you describe what sort of effect you are trying to create?

[xKosta]

Hi Borba,
does the Amplify Shader Editor officially supports Unity 2017? I am struggling to get the tessellation shader up and running. Most of the time I get this error Message "Shader error in 'ASESampleShaders/Tessellation': 'vertexDataFunc': output parameter 'v' not completely initialized at line 57 (on d3d11)" even on the example Shader of ASE.

It is quite difficult to identify what is the excat problem. I am using Unity latest Version and if I just add some nodes, the shader breaks. Model becomes pink or completely transparent. It feels like it is not very stable.

Rest of the Shader Editor works without any problems, it is only with tessellation.

Right now I am trying different solutions to create a highpoly model by scaling it up with displacement preferably on gpu.

Thanks for your help.

[Amplify_Borba]

ASE does indeed support Unity 2017.

I've just tested our tessellation sample with the latest Unity version and wasn't able to replicate your issue, everything is working as expected.

In order to help us debug the problem you're having, could you share with us if you're on OSX or Windows, and could you try to replicate the issue in a new project? Also, did you remove all vertex color nodes from the Tessellation input?

If you're not able to replicate in a new project, please send us a sample from your current project where the issue presents itself so we can examine it.

Looking forward to your reply!

[xKosta]

Hi Borba,
good News, I now identified the Bug, it is the "Enable Instancing" Checkbox. On "OFF" everything works just fine, switch to "ON" you should see that the object gets full transparent, click on "Open Shader Editor" and compile again. The object now becomes pink.

To reproduce, just create new project in Unity 2017, add ASE, create default Unity sphere, create new material and assign ASE example Tessellation shader. Now try to reproduce the same behaviour with "Enable Instancing". I also can send you an empty project, where I can reproduce the scenario. It is about 100MB, I dont know where to upload. But I think it is not needed, cause it is easy to reproduce .

If you having trouble to make the shader run again, you need to delete the object that is using it, than navigate directly to the shader file and import it manually through the context menu, than click the shader file, open ASE and compile, material should be normal again, not pink.

Hope this helps you.

[Amplify_Borba]

Thank you for the additional information!

We were able to replicate the issue, it has been escalated to our engineers and it will be looked into, I'll get back to you when we've nailed it down.

A sample would still be welcome in order to help us with debugging, if possible share it via WeTransfer.

Apologies for the inconvenience!

[xKosta]

I uploaded the sample project, there is nothing special, maybe it helps. I used this mail [email protected]

As a developer, it is always good to hunt down the bugs

[Amplify_Borba]

It seems that this is an Unity error, since Tessellation only works with instancing if there is any variable of the "instanced" type, but since you're enabling instancing without adding any instanced property, the error occurs.

I'm afraid there's nothing we can do since this is how Unity handles this workflow.

Please let us know if you have any further questions or issues!