From ba7ea27ddee4398afa98a0e45b9e227bbcfae906 Mon Sep 17 00:00:00 2001 From: skal Date: Sun, 8 Mar 2026 11:36:04 +0100 Subject: fix: negate Y in perspective() to correct rasterized 3D orientation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The fullscreen post-process VS uses Y-up UVs (uv.y=0 = bottom), so textureSample() Y-flips any rasterized offscreen texture. SDF effects author their content Y-down and look correct after the flip. Rasterized effects (RotatingCube, Hybrid3D) must pre-flip their geometry: - mat4::perspective(): m[5] = -t (negated Y scale) - Pipelines with cullMode=Back: frontFace = WGPUFrontFace_CW (Y-flip reverses winding, so CW becomes the visible face) - Remove incorrect transposes from GlobalUniforms::make(), ObjectData::make(), and Uniforms::make() — mini_math is column-major, no transpose needed for GPU upload - Document the convention in doc/3D.md under "Rasterized 3D and the Y-flip rule" handoff(Gemini): Y-flip rule now documented; all rasterized 3D pipelines must follow it. Co-Authored-By: Claude Sonnet 4.6 --- src/3d/renderer_pipelines.cc | 1 + 1 file changed, 1 insertion(+) (limited to 'src/3d/renderer_pipelines.cc') diff --git a/src/3d/renderer_pipelines.cc b/src/3d/renderer_pipelines.cc index be4a317..2950a7f 100644 --- a/src/3d/renderer_pipelines.cc +++ b/src/3d/renderer_pipelines.cc @@ -249,6 +249,7 @@ void Renderer3D::create_mesh_pipeline() { pipeline_desc.vertex.buffers = &vert_buffer_layout; pipeline_desc.primitive.topology = WGPUPrimitiveTopology_TriangleList; pipeline_desc.primitive.cullMode = WGPUCullMode_Back; + pipeline_desc.primitive.frontFace = WGPUFrontFace_CW; // Y-flipped perspective pipeline_desc.multisample.count = 1; pipeline_desc.fragment = &fragment_state; pipeline_desc.depthStencil = &depth_stencil; -- cgit v1.2.3