[RELEASED] Cloth Dynamics

[Nexusmaster]

Next week I will upload a Unity2019 version!

[kalinins1998]

Hi, I am using Unity 2020.3.6f1 HDRP My system
AMD RX480 RedDevil / Xeon X5650 6/12 / 24Gb I can’t see clothes on the scenes from the examples. I do not see any errors either during playback or in shader compilation. Maybe I’m doing something wrong, what could be the problem?

[Nexusmaster]

Are you using HDRP? You can select the cloth objects in the hierarchy and apply normal Lit materials to them. When you hit run the system should replace them. Check if the shaders are imported correctly. Sometimes shadergraph shaders do not get imported right. Just select them and press reimport. Also a screenshot with the selected cloth and the material would be more helpful. (Search for the Shaders folder and reimport them, see my long video tutorial)

[Nexusmaster]

[Nexusmaster]

If this does not help write me a PM and I will try to figure it out, thanks! And sorry there might be still some bugs I will try to collect and fix them all next week with a new update!

[julesd]

Same here. And I have tried everything you said. Shows in editor but not runtime.
Unity 2020.3.6f1; HDRP; AMD 5700XT
I believe it has something to do with the mesh and not the material.
I believe it is the GPU Cloth Dynamics Script. If I disable it and run I am able to see mesh. With SimpleShapes Scene.

The GPU Skinning (Script) also I believe.

Wish I had a RTX 3090 and test it perhaps it is AMD cards.

I noticed that when I run it. The check mark in the box for ‘Render’ in the GPU Skinning (Script) get’s unchecked at run time. Could that have anything to do with it?
I am not a programmer but I believe for sure the problem is in ‘GPU Skinning (Script)’

[christoph_r]

@Nexusmaster

Hi one_one,
thanks! Good questions! Did you already download the Windows Build Demo and test it on your computer? If you press Win+G or use the Nvidia Overlay, you can get an FPS display.
It’s really not that simple to showcase all the scenarios, because also the Builtin and HDRP setups run on a different FPS.
In the demo there is a setup with 6 characters each has two cloth sims using the LOD switch (for turning the cloth sim off in the background). Also the multi belly dancer scene has 3 character sims running at the same time. But basically I would recommend not to use so many sims at the same time. Also it makes sense to pack cloth parts together e.g. shirt plus trousers as one sim for one character. Cloth Dynamics is focused on character clothes.
In all the test scenes I get an FPS count between 60 and 90 fps with FullHD Res, I have an GTX 1080, a i7-3820 CPU @ 3.60GHz and 32GB RAM.

The compute shader results get send directly to the cloth shader of the cloth materials. So there is no CPU readback. However, I used an Async GPU Readback for calculating the bounding box position of the cloth vertices, so the voxel grid can be positioned around the cloth, but this does not affect the performance and can be also be switched off if your cloth stays more or less in the same place.

Currently most performance loss accrues when you use too many primitive colliders per character or you have too many vertices colliding at the same place (see stress test).

I will soon post some video tutorials, sorry for the delay (again) !
All the best,
Chris

Great, that’s very helpful! Nope, admittedly haven’t tried the demo build yet. Good to hear there’s no CPU readback for the rendering. I see that the shaders are integrated into HDRP Lit shaders - would it be feasible for this to be packed into a shader graph node?

[Nexusmaster]

@julesd is the demo build running on your sytem, when it works it should also work in unity. Can you please select a cloth material in playmode and make a screenshot of the complete unity editor? Thanks!

[Nexusmaster]

@julesd

The check mark in the box for ‘Render’ in the GPU Skinning (Script) get’s unchecked at run time

Yes that might be the problem, can you try and turn on “use custom voxel center”, I think the GPUReadback does not work correctly with AMD cards, I have to further investigate this. If you can’t see the green bounding box it might not work correctly.

[Nexusmaster]

@christoph_r

would it be feasible for this to be packed into a shader graph node?

They are shadergraph shaders, but I can also make a sub graph if you prefer this.

[julesd]

No still does not render mesh.

@Nexusmaster

Yes that might be the problem, can you try and turn on “use custom voxel center”, I think the GPUReadback does not work correctly with AMD cards, I have to further investigate this. If you can’t see the green bounding box it might not work correctly.

No still does not render mesh to screen. While performing simulation.

[christoph_r]

@Nexusmaster

They are shadergraph shaders, but I can also make a sub graph if you prefer this.

Yes, that would be great because I have a custom clothing shader setup

[Nexusmaster]

@julesd

No still does not render mesh to screen. While performing simulation.

@julesd and @kalinins1998 I will run a test with my old AMD laptop, maybe I can figure it out.

[julesd]

If any one else has a AMD card and Cloth Dynamics for unity could you please post your results with Cloth Dynamics?

[Nexusmaster]

@julesd & @kalinins1998 :
Good news, I could test it on my old AMD laptop and also the cloth gets invisible in URP (HDRP is not working on this laptop). I switched to builtin and it works! So it must be some issue with the shadergraph shader. Can you please try the builtin content (please delete the HDRP content first) and see if that works. Thx!

[Nexusmaster]

Of course I will now try to fix the issue in URP and try to transfer the results to HDRP. But please let me know if builtin works for you, so that we are on the same page.

[Nexusmaster]

Ok, so here is the fix ( I will upload it in my next version 1.2):

go to:
Assets\ClothDynamics\Resources\Shaders\SRP
open:
ClothFunc.hlsl

and rewrite this:

Buffer<float3> positionsBuffer;
Buffer<float3> normalsBuffer;

into this:

StructuredBuffer<float3> positionsBuffer;
StructuredBuffer<float3> normalsBuffer;

reimport the shadergraphs or open the shaders in the graph and save them. Thats it.

[Nexusmaster]

So, I uploaded the changes, should be available in two days in the store.

[julesd]

Thanks.

[Nexusmaster]

I found a minor bug happening only with android, you need to replace following line in GPUClothDynamicsEditor.cs to fix it:

#if UNITY_ANDROID || UNITY_IPHONE
                                EditorGUILayout.LabelField("This feature doesn't work on mobile devices!", s);
#endif

to

#if UNITY_ANDROID || UNITY_IPHONE
                                EditorGUILayout.LabelField("This feature doesn't work on mobile devices!", orangeStyle);
#endif