Grass Shader
25 October 2023
I wanted to recreate the changing seasons and I thought of making a floor of fallen leaves that start out green then transition to orange/reds to brown and then covered in snow before it melts and the leaves are green again.
I started piI underestimated the amount of work that it would take just to start out. First I couldn't really figure out how to make a proper leaf shape with the sharp tapering on the top and bottom as well as the details within the leaf. Then I had issues coming up with ways to simulate/create a pile of leaves nicely, I was struggling to layer them on top of each other.ece by piece by breaking the effect into parts and combining them together at the end.
After struggling for a few hours, I decided to cut my loses and just go for a simpler concept. Basically having blades of grass that grow up from the ground that turn from green to brown and 'wither away' at the end.
Grass Blade Shape
- I start off by creating the shape of the grass. I used the Twirl node to have the Rectangle shape warp a little to the side, creating a droopy blade of grass then adding them together to create 3 blades of droopy grass.
Grass Blade Color
- I colored the grass by getting the G value of the UV to mask out the top half of the grass from the bottom half so it creates a gradient of ground color to a bright green leaf color. I also made the second version (Brown) using the same nodes. The nodes are then lerp together with a Fade transition node that swaps both colors in and out following a time - sine wave.
Grow / Wither Animation
- The growing/wither animation I did was pretty much the same concept, but I used the UV's Green channel and two Power nodes to make the gradient move up and down on Cosine Time. I added the Posterize Step node just to make it look more blocky / stylistic.
Wind Animation
- I looked up a tutorial on how it was done and just emulated it.
Shadergraph Overview
- An overall look at the entire shadergraph
Final Result + Thoughts
- It ended up looking more like seaweed instead of normal grass, but I think I still managed to achieve what I set out to do :D