Vulkan Grass Rendering

University of Pennsylvania, CIS 565: GPU Programming and Architecture, Project 5

• Janet Wang website
• Tested on: Windows 11, i7-12700H @ 2.30GHz 16GB, Nvidia Geforce RTX 3060 Ti 8054MB

Summary

This project is a Vulkan grass simulator and renderer based on the paper Responsive Real-Time Grass Rendering for General 3D Scenes. It uses compute shaders to perform physics calculations on Bezier curves that represent individual grass blades in the application. It also uses compute shaders to cull grass blades that don't contribute to a given frame to improve efficiency. The remaining blades will be passed to a graphics pipeline, in which a vertex shader transforms Bezier control points, tessellation shaders dynamically creates the grass geometry from the Bezier curves, and a fragment shader shades the grass blades.

Results

Grass with gravity, recovery, and wind forces.

Grass without force.

Cullings

Orientation culling	View-frustum culling	Distance culling

Performance Analysis

• Performance with different numbers of grass blades

• The improvement got by culling using each of the three culling tests

Test view 1 is chosen so that both orientation culling and view-frustum culling are working to cull some of the blades.

Test View 1	Result

Test view 2 is chosen so that both distance culling is working to cull some of the blades.

Test View 2	Result