- Vertex shader: passes world position, world normal, albedo to fragment
- Fragment shader: full PBR implementation
- D term: Trowbridge-Reitz GGX distribution
- G term: Smith geometry with Schlick-GGX
- F term: Schlick Fresnel approximation
- kD/kS split based on metallic
- Directional light (0.5, 0.8, 0.3) with warm color
- Ambient term (0.15, 0.18, 0.22) for fill light
- ACES filmic tonemapping
- Gamma 2.2 correction
- Fixed roughness=0.5, metallic=0.1 (per-object materials = future)
- No C# code changes — pure shader upgrade
- Vertex shader: pass normal through mat3(model) to fragment
- Fragment shader: directional light (0.5, 0.8, 0.3) with 0.25 ambient
+ 0.75 diffuse = faces now have depth and 3D form
- Torus knot has smooth normals (vn in OBJ), cubes have face normals
- 0 validation errors, ~2300 FPS
Root cause: System.Numerics.Matrix4x4 uses row-major storage with row-vector
convention (v * M). GLSL with layout(row_major) does column-vector (M * v),
which effectively transposes the matrix, breaking the projection.
Fix: remove row_major from layout qualifiers. GLSL then interprets the
row-major data as column-major (effectively transposing it), so M * v in
GLSL equals v * M in System.Numerics — correct result.
The Y-flip (M22 *= -1) is still needed for Vulkan's Y-down clip space.
- Push constant changed from float angle (4B) to mat4 model (64B)
- Two draw calls with different model matrices (x=-1.5 and x=+1.5)
- Both cubes rotate around Y axis at 0.2 rad/s
- 0 validation errors
- vkCmdBindIndexBuffer indexType changed from 0 (UINT16) to 1 (UINT32)
to match uint[] index data — this was causing black screen
- Removed depth stencil state, depth attachment format, and depth
rendering attachment from pipeline/renderer (depth buffer still
created in swapchain but unused)
- Fragment shader: directional light dot(normal, lightDir) with 0.2 ambient
- Vertex shader: pass normal through mat3(model) to fragment
- Same-color faces now have different shading based on orientation
emil28092005