RoyTheunissen/GPU-Spline-Deformation

Sample for baking deformation to a texture then applying it to a mesh via a shader.

About the Project

I saw Simon Trümpler's Tileable Liquid Mesh on Spline and I was wondering how the mesh was following the spline exactly. It gave me the idea of baking the deformation to a texture somehow, which actually turned out to be really simple.

Video | Article

Getting Started

• Add the package to your Unity project (tips on how to install it are in the Installation section)
• Create the mesh you will be deforming that's pointing in the forward Z axis. Samples are provided.
  • Make sure it has a material with the Deformation Lookup Shader shader.
  • If the mesh does not start at (0, 0, 0) and stop at (0, 0, 1), adjust the Z Start and Z End properties accordingly.
• Implement the IDeformationProvider interface in the script that is responsible for the deformation that you want to bake or use the provided BezierSpline script.
• Add a DeformationTextureRenderer script to the scene. I recommend adding it next to the mesh you'll be deforming.
• Assign the script responsible for the deformation to the Deformation Provider field.
  • Assign the material for the mesh that will be deformed (this is necessary for assigning it dynamically created textures)
• You should now see the mesh deform along whatever deformation is provided via the script.

Troubleshooting

• If the mesh is not deforming, check that Amount is set to 1 in the material. This feature exists for quickly toggling the effect on and off to see what it does.
• If the mesh is not deforming, check that it has the right material, shader and texture assigned
• Make sure the correct texture asset and/or material are assigned in the Deformation Texture Renderer
• If you are seeing artifacts or incorrect deformation:
  • Make sure the resolution is sufficiently large. Set the mode to Dynamic and try out larger resolutions until the artifacts disappear
  • Make sure Z Start and Z End are set correctly in the material
  • Make sure the texture's wrap mode is set to clamp. For looping meshes you may want the X-axis to be set to Repeat

Installation

Package Manager

Go to Edit > Project Settings > Package Manager. Under 'Scoped Registries' make sure there is an OpenUPM entry.

If you don't have one: click the + button and enter the following values:

• Name: OpenUPM
  
• URL: https://package.openupm.com
  

Then under 'Scope(s)' press the + button and add com.roytheunissen.

It should look something like this:

Git Submodule

You can check out this repository as a submodule into your project's Assets folder. This is recommended if you intend to contribute to the repository yourself

OpenUPM

The package is available on the openupm registry. It's recommended to install it via openupm-cli.

openupm add com.roytheunissen.gpusplinedeformation

Manifest

You can also install via git URL by adding this entry in your manifest.json

"com.roytheunissen.gpusplinedeformation": "https://github.com/RoyTheunissen/GPU-Spline-Deformation.git"

Unity Package Manager

from Window->Package Manager, click on the + sign and Add from git: https://github.com/RoyTheunissen/GPU-Spline-Deformation.git

Contact

Roy Theunissen

[email protected]

Acknowledgements

• Tileable Liquid Mesh on Spline, Simon Trümpler for the inspiration
• Curves and Splines, Catlike Coding for the spline implementation