GPU Cloth Simulation
| cloth with force visualization | cloth with diffuse render |
|---|---|
 |
 |
This repository is about GPU based Mass-Spring Simuation in Unity. Based upon Compute Shader, calculates physics in parallel.
This project is a sub project of ReclothSimulation-master, a private repository, some of features are removed in this repo.
- Mass Spring System Cloth
Inter Object Collision-ResponseSelf Collision-ResponseDynamic Collider Generation
Currently Confirmed working on following platforms:
- Unity Engine version 5.6.1f2 ~ 2018.2.0b10
- Windows(OpenGL Core)
- Android(OpenGL Core)
How to use
Create a empty GameObject on hierarchy panel and append ClothSimuation and ClothRenderer scripts on it. Since this simulation calculates with its own system, you'll need special materials and dedicated shaders for rendering. There are two example materials(Face Normal Rendering, Diffuse Rendering).
Attributes
Cloth Simulation
Compute Shaders
| attributes | description |
|---|---|
| NodeUpdateComputeShader | a compute shader which updates forces, positions, velocities, etc. |
| TriCollisionResponseComputeShader | a compute shader which calculates collision with floor |
| NormalComputeShader | a compute shader which calculates all face normals of the cloth model |
Attribute of Cloth
| attributes | description |
|---|---|
| VertexColumn | numbers of nodes in a Column |
| VertexRow | numbers of nodes in a Row |
| ClothSize | Size of cloth object in Unity world scale |
| ClothMass | Mass of cloth object |
| Looper | amount of looping compute shaders per frame, larger number for precise, slower simulation |
Constant for Cloth
| attributes | description |
|---|---|
| SpringK | spring force from Hooke's Law |
| Damping | damping coefficient for cloth simulation |
| External Force | external forces such as wind, water etc. since it is public member, you can pass from external scripts |
Cloth Renderer
| attributes | description |
|---|---|
| Mat | a material for Cloth Object. |
| LightGameObject | a light-type Gameobject, especially for diffuse rendering. Directional light recommended. |
| MeshTopology | which element to draw Cloth: currently triangles supported, but you can write your own shader for others. |
Caveats
Since the simulation is not pretty stable, certain values for the clothSimulation scripts are recommended:
recommended parameters of Attribute of Cloth
| attributes | values |
|---|---|
| vertexColumn | 8 ~ 64 |
| vertexRow | 8 ~ 64 |
| Looper | 20 ~ 500, larger values for more stable simulation |
recommended parameters of Constant of Cloth
| attributes | values |
|---|---|
| SpringK | 10000~ 50000, but for a non-elastic behaving typical cloth, values around 35000 is recommeded |
| Damping | 100~200, can be vary by SpringK |
recommended parameters of Cloth Renderer
| attributes | values |
|---|---|
| Mat | requires custom shaders, look at the normalShader and DifwithShadows in shader->render directory. |
| LightGameObject | Directional Light is highly recommended |
| MeshTopology | You can use all of MeshTopology types, but you should write your own shaders. The embedded two shaders use MeshTopology.Triangles. |
Performance
Since this project uses Unity engine and GPU computing, it runs on most platforms, even mobile in real-time. But the performance heavily depends on the size of the model's triangles which you want to make it collided
Contact
You can contact Minsang Kim via e-mail([email protected]).
License
This Project is licensed under the MIT License
Copyright (c) 2018 Minsang Kim
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Acknowledge
This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(Ministry of Science, ICT & Future Planning) (No. 2017R1A2B1005207).