Polygon Wind Shader

In 2017 I was looking for a wind shader to use on a low poly tree model. I couldn't find one that provided the visual I was looking for, so I started to develop the Polygon Wind Shader.

It is designed to generate a more suttle and organic wind movement on trees. But it's not great for heavy wind effects. Lately I haven't had much time to work on it, so I decided to publish the source code here and make it available so that anyone can use and modify it.

Here are some videos of what I achieved using it:

• Using on individual model
• Using on a Unity Terrain

How to use it:

Just apply the shader to a material and apply the material to your asset. The ideal tree asset is one with a single mesh.

The shader has various parameters for you to tweak:

• Wind Wave Size;
• Tree Sway Displacement;
• Foliage Wiggle Amount;
• Branches Up/Down;
• Foliage Wiggle Speed;
• Tree Sway Stutter;
• Tree Sway Speed;
• Wind Direction;
• Red Vertex Influence;
• Blue Vertex Influence.

It uses a series of inputs to calculate the final vertex position, one of them being the vertices colors of the mesh:

• Red - Use on the branches to enable the up/down movement;
• Blue - Use it on the leaves to get that organic wiggle.

Known uses of the shader by other people

• Borrie's Swaying Trees mod for Star Wars Galaxies, by Borrie BoBaka.