DirectX Fundamentals
A series of progressive DirectX 12 labs covering the full GPU rendering pipeline — from a bare triangle to geometry-shader billboards and tessellated heightmap displacement.
About This Project
A set of progressive DirectX 12 labs that walk through the GPU rendering pipeline stage by stage — starting from a single triangle and building up to camera-facing billboards generated in the geometry shader and terrain displaced by a heightmap through the tessellation pipeline. Hands-on training in low-level HLSL shader programming.
Engineering Highlights
Camera-aligned billboards in the geometry shader — The geometry shader expands each input vertex into a camera-facing quad (two triangles), emitting up to 18 vertices per triangle. It builds a view-aligned orthonormal basis on the GPU: look points from the vertex to the camera, cross(look, world_up) gives right, and cross(look, right) gives up. The pixel shader discards fully black fragments for cheap alpha cutout transparency without blend-state changes.
Heightmap displacement via tessellation — After the hull shader sets tessellation factors, the domain shader bilinearly interpolates the four patch corners across the generated SV_DomainLocation, samples a heightmap texture at the interpolated UV, and displaces the vertex’s Y coordinate before projecting to clip space — turning a flat quad patch into displaced terrain entirely on the GPU.