One concept each, all interactive. Every demo belongs to a
note in Brain/graphics/ — the note explains it, the demo makes
it obvious. Drag things.
One triangle stepped through every stage, with the vertex count next to the fragment count.
01-render-pipeline.md 02The same scene redrawn in model, world, view, clip and screen space. Watch the frustum become a cube.
02-coordinate-spaces.md 03Drag triangle vertices over a pixel grid; toggle the depth test and watch z-fighting appear.
03-rasterization-and-depth.mdLive fragment shaders with their source beside the picture. Uniforms on sliders.
04-shader-basics.md 05Drag the light. Isolate ambient, diffuse and specular, then add them back together.
05-lighting-and-shading.md 06Nearest vs bilinear, mips on vs off, and the shimmer that appears without them.
06-textures-and-sampling.mdBreak transparent geometry by sorting it wrong, then fix it. Blend arithmetic shown per pixel.
07-transparency-and-blending.md 08Blur, bloom, tone map, vignette — stack the passes and see the chain.
08-post-processing.md 09The light's depth buffer as a strip. Crank bias until acne turns into peter-panning.
09-shadow-mapping.mdDrag two shapes together. SAT's candidate axes and shadows drawn live.
10-collision-detection.md 11Restitution, friction and solver iterations — each one has a visible failure mode.
11-collision-response.md 12Euler drifting against semi-implicit and RK4, with an energy graph that doesn't lie.
12-integration-and-timestep.md 13Brute force's pair count exploding while the grid's stays flat.
13-spatial-partitioning.mdEvery bounce drawn in a top-down box, beside the strip of pixels those rays produced.
14-raytracing.md 15The distance field as contour bands, with step circles shrinking onto the surface.
15-raymarching.mdOne forward vector in side and plan view at once. The plan circle's radius is cos(pitch) — shrink it to nothing and watch the basis collapse.
16-rotation-and-orientation.md 17Reverse a slide mid-flight, change the frame rate under two followers, and drag an angle across the ±180° seam.
17-interpolation-and-easing.md