[RELEASED] Cloth Dynamics

Is it possible to use the HDRP silk shader with this or to set up something similar?

 

Hi, I want to manipulate clothes(i.e. folding or flatting a T-shirt) with hands on a table-top scene. I mainly care about the physics simulation rather than the rendering quality.
I have a few questions:
1. If I turn on self-collision, can it run at real-time on a RTX 3090 GPU with cloth mesh that contains ~10K vertices?
2. Does it support multi-GPU? If I have multiple GPU, will it run faster?
3. Can I add or remove pin constraint dynamically at runtime? For example, I want to attach one vertex of the cloth to my hand mesh when the hand touches the cloth, and releases the attachment when needed.
4. Does it support VR in the latest version?

I already bought Obi Cloth, but it is too slow to support our need. If Cloth Dynamics is efficient enough and have these properties, I will definitely buy it!

 

Hi, should be possible, try to use the cloth subgraph and link the outputs to vertex, normal and tangent input.

 

1. Yes, should be no problem with 10k cloth, see the latest demo on the asset store, there is a scene with 2 cloth objects using self collision.
2. I didn't test it. You can test it by downloading the demo or one of the free github Unity sources, that use compute shaders.
3. You can add constraints to your scene and turn them off and on during runtime. Currently they get cached in a list to the CD component at the start.
4. VR should work, but i didn't try it. Cloth Dynamics does not use any camera effects that affect stereo view, however you might need to turn off the cloth frustum culling or increase the bbox. Both options can be set in the gpu cloth dynamics inspector. Maybe the Projection Mask does not work in VR, but it sounds like, that you don't need it.
If it doesn't work for you, you can get a refund!

 

I checked the FightSceneHD, it has 105.696 triangles in total, one T-Shirt has 34.668 and the Trousers 18.180 triangles. The total cloth vertex count of this scene is 55.682.

 

Hi again. So after buying and playing around with this asset, I can definitely say that I'm pleased with it. There's just a few things holding me back from using it in my project, and it mostly comes down to the fact that my character mesh can change drastically during runtime. (Think character creator with body sliders and such)

The main issues I'm facing are:

1. My character shader already uses every vertex color for specific things. I'd like to do the same with my clothing shader, but this would conflict with the weighted cloth blending functionality, no? Would it be possible to add the option of using a texture instead of vertex colors for that kind of thing?

2. The collidable surface of a skinned mesh updates accordingly for bones, but blend shapes have no effect. Or am I missing something?

3. Vertex positions for my character mesh can change during runtime, but updating the mesh itself has no effect on the collisions. Makes sense since you'd normally only need to get the vertex positions once. Is there some way I can apply changes to the vertices used for collision or would that break everything?

If these problems are more than trivial to solve then don't mind me - just figured I'd ask.

 

Thanks for your support!
1. Yes, I want to fix this anyway, best would be if the shader graph supports vertex IDs. Maybe with Unity 2021 beta, which version are you using btw.?
2. You are right, currently there is a lack of blend shape support. I will have a look how hard it is to add this.
3. This sounds more tricky, but it is possible to apply, are you using CPU or GPU vertex modifications?

Most of these issues can be fixed, when I add the new Unity 2021 Vertex Buffer, so if you want to work with the Unity beta version, you can soon use this.
https://docs.unity3d.com/2021.2/Doc...ence/SkinnedMeshRenderer.GetVertexBuffer.html
I already started with it, there are just some transformation issues that will take so time to fix, but I think it's possible.

 

Sounds good! I'm already on the beta version and can upgrade as necessary. The vertex modifications take place on the CPU. If it ends up being possible to update the collision vertices, then I can similarly apply blend shapes on the CPU for now

 

Update: Currently there is an issue with the NeighbourCheck and Self Collision system, I will try to fix this asap. Sorry about that, it must have been sneaked in when I did some changes. For now just turn off "Use Neighbour Check".

 

Hey there- I'm interested in buying Cloth Dynamics but have some DAZ questions.

1) You selected a dforce dress in the unity workflow video. Do you have to have dforce applied to clothing for Cloth Dynamics to work?
2) In the unity workflow video. You imported the model into blender instead of directly into Unity3D using the DaztoUnity bridge. Is the blender step absolutely required? (wMagicaCloth this isn't required)

 

Hi, the video just showed my personal workflow, but you can do it completely different, Cloth Dynamics just needs a mesh, you basically can use any mesh as a cloth mesh, however the results will differ, normally I recommend a uniform mesh, where all edges have the same distances. e.g. Marvelous Designer.
I never tried DazToUnity, because with the Diffeomorphic Blender plugin I have many options to edit the mesh, also in Blender I can decimate the mesh to make it more low poly.

 

Hi, I finally found the bug which caused a slowdown with self collision (and NeighbourCheck).
I will upload a new version with the fix today! Sorry for the delay!

 

So, I sent the latest version 1.6.7 to the asset store! Will be soon available!
Please DELETE the old ClothDynamics/Resources Folder before updating!
Thanks!

 

Hi! Does this plugin support self-friction? For example, if I try to fold clothes, are there some kind of friction forces between the cloth's own particles?

 

You can use the static friction slider for mesh collision. There is also a friction component, which works with primitive objects. The dynamic friction slider affects the primitive collisions globally.

 

The new version 1.6.7 is now online, please update!

 

Hello! Does Cloth Dynamics support scaling object with cloth at runtime?

 

hi ,
I bought this package that I can use it on all systems, but I get the Platform error does not support compute shaders,
Does this package only work on systems that support compute shaders?

 

Hi, sorry but you could have read the description on the asset store:
"
Description
Cloth Dynamics is a fast and advanced particle-based physics system mostly running on the GPU with compute shaders.
Additional compatibility information
NO WebGL support !!!
"
Currently WebGL is the only "platform" I know that doesn't support all compute shaders (and also old mobile phones..)

Which platform are you using?

Send me an email please with your invoice no. and I can give you a refund.

 

At the moment it does not work out of the box, I will add this feature to my TODO list.

 

Thank you everyone for been so patient the last weeks, I was very busy, but now I will try to finish the user requests and update the documentation! I think it makes more sense to finish the new features first and then update the docs.

 

I got this asset for a friend of mine. If you repay it, thank you very much,
I'm sorry I did not see the description of compute shaders
I wanted to use it on all Android phones, but only a limited number of Android devices support compute shaders.

And I did not find your email to send the invoice

 

@Nexusmaster, I've been publishing the cloth dynamics examples to mobile and I haven't seen a scene that will work without some kind of issue out of the box. I am publishing to iPhone 12 Pro. For example the AnimeCharacter scene, the dress is flowing but the top is not on the character. The DressNoPC scene, the dress just explodes. Are there any examples you would say run well on iOS?

 

Hi, yes there are currently not many examples that work on mobile, I will add a mobile example scene, that is a good idea! What I tried is the AnimeCharacter, but I just used the skirt as a cloth object and turned off the "Collision Finder".
Here is a quick test, sorry the settings are not perfect, need to fix the skin overlapping via projection mask:

(This gif video looks kind of slow, but normally this runs faster, I think this is from the avi to gif conversion.)

 

Tomorrow, I will update the new changes,
today I had to release my first steam page:
https://store.steampowered.com/app/1773990/Power_Pushout/




This is my first game using Cloth Dynamics, this game will also be released on mobile later.

Btw.: It also helps if you add Power Pushout to your Wishlist and follow it, so I get more awareness from the steam bot/ai system, which will give the product more visibility. I will do the same for your game if anyone needs the support! I also offer to write reviews for other game devs, we need to work together!

 

I have this project which is kinda a character creator, where the base mesh has blend shapes and the character is animated, somehow like posing. And i want the clothes to have realtime simulation. I have tried other cloth simulators but they dont really do what i want, the collisions between the character mesh and the cloth is never perfect.

Will this asset work well for this situation? And will it work on WebGL?

 

Hi, it should work well, in the last version I added a projection mask feature, so even when cloth will overlap with the body in some fast movement situations, now the "mask" will hide the body underneath.

I also added a new feature, which will be available in the next version, which will be soon on the asset store:

GPU Blend Shapes, before you could only use the character body without blend shapes, but now with this new script you can also use Blendshapes as if it would be the normal skinned mesh blendshapes.

However, I currently can't support WebGL, because of the memory limits it has. Maybe at some point I will support it, but now it's not possible.

Thanks for asking! Have a nice day!

 

Something is not right here but I can't tell, I think, the vertices just get the bones rotation but not the bones translation, very weird... testing 2021 beta -> skin.GetVertexBuffer();

Edit: Ok, I found the solution: I need to transform the vertex buffer data with the skinned root object! But it only works if the skinned mesh has the correct root bone object applied... this can be tricky, e.g. the Kyle model had a different root bone as default than the original root bone.

Anyone who wants to try it out:

Code (CSharp):

1. using System;
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. public class TransferGPUSkin : MonoBehaviour
7. {
8.     Vector3[] verts;
9.     public Transform _rootBone;
10.  
11.     void Update()
12.     {
13.         var skin = this.GetComponent<SkinnedMeshRenderer>();
14.         skin.vertexBufferTarget |= GraphicsBuffer.Target.Raw;
15.         var vertexBuffer = skin.GetVertexBuffer();
16.  
17.         if (vertexBuffer != null && vertexBuffer.IsValid())
18.         {
19.             byte[] data = new byte[vertexBuffer.count * (skin.sharedMesh.GetVertexBufferStride(0))];
20.             vertexBuffer.GetData(data);
21.  
22.             int stride = skin.sharedMesh.GetVertexBufferStride(0);
23.  
24.             int length = data.Length / stride;
25.             if (verts == null) verts = new Vector3[length];
26.             for (int i = 0; i < length; i++)
27.             {
28.                 int dataStep = i * stride;
29.  
30.                 for (int n = 0; n < 3; n++)
31.                 {
32.                     int floatStep = dataStep + n * 4;
33.                     verts[i][n] = BitConverter.ToSingle(new byte[] { data[floatStep], data[floatStep + 1], data[floatStep + 2], data[floatStep + 3] });
34.                 }
35.  
36.                if(_rootBone!=null){
37.                  verts[i] = _rootBone.localRotation * verts[i];
38.                  verts[i] += _rootBone.localPosition;
39.                }
40.             }
41.         }
42.     }
43.  
44.     private void OnDrawGizmos()
45.     {
46.         if (verts != null)
47.         {
48.             for (int i = 0; i < verts.Length; i++)
49.             {
50.                 Gizmos.DrawWireCube(this.transform.TransformPoint(verts[i]), Vector3.one * 0.001f);
51.             }
52.         }
53.     }
54. }
55.  

 

Hi,
When I start my game my texture goes missing? It's always a white cloth? How can I fix this?

Kind regards,
Dries

 

Hi Dries, sorry, this part is still missing in the docs, I will update them with the next version. CD needs to replace the cloth material shader, so that is why it might change your texture. You can select the cloth shader for your material before hitting play and it won't change the texture. Just have a look which shader it uses by selecting the cloth and unroll the material inspector. If you know which shader it uses you can apply this one before you start the Play mode. You can also create a custom shader, but this needs to be a shader with the name "Cloth" in it, so it won't get replaced.

The same happens with the Body material, if you are using mesh collision. You also need to check the shader. They have a "Skinning" in their shader name.

Hope this helps,
All the best,
Chris

 

I finished the work with the GPU VertexBuffer, just making the Docs on monday and it's done.

 

Hi!
Here are videos of the new features:

 

Hi, I'm facing a problem.
In a project using HDRP, the simulation stops as soon as it starts in the built application, while it works fine in the editor preview.
When it stops, it looks like below, and no errors in the debug console.
Is there any way to fix this?
My Unity version is 2020.3.17f1.

 

Hi,
I had a similar issue, but I could fix it via adding the CD shaders to the included shaders:

They should be automatically included by Unity, but somehow it didn't work so I tried it this way.
Just include the shaders that your materials are really using.
Hit Play Mode and check the materials of the cloth and the body meshes in the Editor, select these shaders and move them to the graphics settings via drag and drop.

Let me know if that works, please!

Cheers,
Chris

 

@Nexusmaster
Sorry if this has already been asked or implemented. (I haven't been looking into release notes that thoroughly.)

Is cloth adaptation to vertex buffer from a custom source still something that's going to be implemented? (Or, alternatively, custom vertex buffer injection into offered vertex buffer.)

Is there an ETA?

Thank you, and awesome work on the updates.

All the best.

 

The new version should be out in store soon!
Next step for me would be to add a custom texture for the data that is currently used in the vertex colors...

@SunnySunshine: I'm not completely sure what you mean, maybe you can tell me what you want to do with this custom vertex buffer?

 

@Nexusmaster
I covered it in detail here:
https://forum.unity.com/threads/released-cloth-dynamics.1019401/page-4#post-7379420

In short - we already have our own custom character skinner, and it would be nice if its data could be used when doing the clothing operations. Alternatively, if that data could be copied to the vertex buffers used by Cloth Dynamics (without having to skin twice).

We also have our own normal computation system that we'd like to use on the clothing.

 

Ah yes, I remember, well with the new 2021.2 version you could change the TransferData() function in the GPUSkinning for your needs.
So basically you just have to transfer your data to the ComputeBuffer "_meshVertsOut", which has the following struct:

Code (CSharp):

1. struct SVertOut
2. {
3.     float3 pos;
4.     float3 norm;
5.     float4 tang;
6. };

I would recommend using the GPUSkinning class as a base class and overwrite the TransferData() method. (You have to add the "overwrite" by yourself, but I can also add it with the next update.)

You find the TransferCS function in the skinning.compute shader.

After that, you might have to modify ClothFunc.hlsl, which reads the cloth data in the ShaderGraph. It makes sense to add an extra keyword e.g. USE_CUSTOM_TRANSFER_DATA.

Because currently the new GPUVertexBuffer needs to be transformed back... maybe I can remove that in the future but for now this was the easiest approach. This is currently still a beta setup and might change.

So overwriting a class is not really as good as an interface, but I think it should work. Sorry but my time (and budget) is limited, so I can't fullfill every wish. But if you make some effort in this direction, I will be more willing to implement it. Thanks!

 

Thanks for your reply.
I tried it on my project, but after a long time of compiling, the build failed with the following error.
The shaders I added are the same as yours.
Is there any other setting I should change?

Regards,

 

@Nexusmaster

Thanks for those pointers. I will most definitely make an effort at some point. Right now I'm busy with other tasks however!

I did try to give it a quick look, but I couldn't find any TransferData() in GPUSkinning, nor any TransferCS in skinning.compute. Is this version live on asset store? (I just downloaded from asset store so I'm using 1.6.7 apparently).

About that - you may want to change the layout of your structs. The one you're currently using will span cache lines and cause performance degradation. More information:
https://developer.nvidia.com/content/understanding-structured-buffer-performance

My biggest fear with editing files like suggested is that my changes will become incompatible with upgrades. It would require repeated investment of time (on my part) if I am to retain compatibility with upgrades. The best thing, over time, would be if the system was generic enough to allow for custom injection, without the need of changing the source.

All the best.

 

Ok, sorry the include stuff is just the easy fix, but looks like it does not work well with HDRP, I tested it with URP. Instead use a shader variant collection:


Mine looks like this:


You can also try my attached file, however it might not find the connections, so maybe it's better to create your own. After that you can build and it should work. Make sure you remove the shaders from the "Always Included Shaders" list.

 

You need version 1.7, should be soon in the store, maybe today or tomorrow. The layout struct is actually made by the unity guys, I never touched the skinning.compute shader, I just added my new function (in 1.7). I know that the performance should be a bit better with 128 bits sizes. However I tried this a lot of times with different gfx cards and I never saw a big difference. Maybe with older cards it makes more impact.
But I will try to change it, if possible: Sometimes it does not make sense for me, when you need an extra cpu loop to adjust your array so it fits the buffer, which has an extra float.
For example: you can directly write your vertex position data to a float3 buffer, but if you have a float4 buffer you need to convert your vertex array again to a float4 array, so you have to cache a float4 array for your mesh, this is no problem when you do it once but when you have to do it each frame it will cost time. Even if it's only in the init phase it can cost loading time if you have a highres model... So your GPU computation might run faster now, with little impact but your CPU computation via C# takes longer which normally makes more impact, because C# is generally slower.

But again I'm sure there is still a lot of optimization potential for Cloth Dynamics, the most suprising fact that other people often forget is that data compression counts a lot more than you think!

 

Btw. for Unity 2020 or newer, open the Lit shaders with the Shader Graph and update the deprecated parameters. (They are signed as "deprecated"). Normally it's the Base Color and the Emission Color. Thanks!

 

I just tried with the file you sent and it works fine now!
Thanks for your support.

 

@Nexusmaster
The latest release has some compilation errors in Unity 2021.2.

Code (CSharp):

1. Assets\ClothDynamics\Plugins\GPUSkinning\Scripts\GPUSkinning.cs(200,24): error CS0115: 'GPUSkinning.TransferData()': no suitable method found to override

Was "virtual" intended?

 

Ah yes, did a quick fix, should be virtual, sorry! I sent a new version to the store, should be soon there.

 

So, the fix is finally in the store! Sorry for the circumstances! I thought "virtual" but wrote "override"...
https://assetstore.unity.com/packages/tools/physics/cloth-dynamics-194408

 

Hi,
so my next plan is to add a layered cloth, because I think it would be really helpful to have one cloth object and not many on top, also the performance would be better.

 

Hi,
In my last post, I asked about a problem that only works when running an app built with the HDRP project.
I implemented a GPU Blend Shapes in the same environment, but it did not work either.
Could you tell me if there are any shaders that I should include as well, along with how to do it?
Sorry if this has already been posted somewhere.

 

When you look into the Plugins folder under "GPUSkinning" you find a Resources folder:
Maybe "BlendShaders/CopyTex" shader
and "BlendShaders/WriteDataToRT" compute shader.
Please try to include these, for more info look in the CD Docs under "Build Settings". I still don't know why they not get included automatically.
Also please check what shaders are used during play mode on your mesh's material, that has the GPU Blend Shapes script applied. Maybe you need to add them too!
If it still doesn't work, write me a PM and we will figure it out. GPU blend shapes is still a very new feature and might need bug fixing.