SurfaceCard

Remarks

A card is a box and an axis. It captures the surfaces inside its box whose normals lean along its direction, looking straight down that direction orthographically — up to six of these cover a mesh from its six sides, which is the whole trick: a surface's radiance becomes a low-resolution 2D texture problem, and radiosity over 2D textures is cheap where radiosity over geometry is not.

The in-plane frame is the other two world axes, in cyclic order, whatever the sign. Direction ±X maps the card's UV to world (Y, Z), ±Y to (Z, X), ±Z to (X, Y). One rule with no branches on sign, so a card and the shader that will someday sample it cannot disagree about which way U runs — the octahedral fold's lesson, one convention over.

Fields and properties (8)

• public int Axis

  Which of the six directions the card faces: +X, −X, +Y, −Y, +Z, −Z.

• public Vector3 Centre

  The centre of its box, in world space.

• public Vector3 HalfSize

  The box's half-extents, world-axis aligned.

• public Int2 Resolution

  Texels along U and V.

• public Vector3 Direction

  The outward direction of the surfaces this card captures.

• public int UComponent

  The world component index the card's U runs along — cyclic from the axis.

• public int VComponent

  The world component index the card's V runs along.

• public (Vector2 Plane, float Depth) Extents

  The half-extent along U and V, and the half-depth along the axis.

Methods (3)

• public SurfaceCard(int axis, Vector3 centre, Vector3 halfSize, Int2 resolution)

  Places a card.

• public Vector3 TexelOrigin(Int2 texel)

  Where a texel's centre sits on the card's near plane — the face the capture enters.

• public bool TryProject(Vector3 world, out Int2 texel, out float depth)

  A world position in the card's own terms, if it lies inside the box.

Used by (15)

• ArenaIlluminationThirdPersonShooter
• CardGeneratorVixen.Rendering.SurfaceCache
• CardRadiosityVixen.Rendering.SurfaceCache
• CornellBoxTestsVixen.Rendering.SurfaceCache.Tests
• SurfaceCacheCardDataVixen.Rendering
• SurfaceCacheGatherFillVixen.Rendering
• SurfaceCacheLightFillVixen.Rendering
• SurfaceCacheRadiosityDeviceTestsVixen.Graphics.Golden.Tests
• SurfaceCacheStoreVixen.Rendering.SurfaceCache
• SurfaceCacheTestsVixen.Rendering.SurfaceCache.Tests
• SurfaceCacheTextureVixen.Rendering
• SurfaceCardCaptureVixen.Rendering
• SurfaceCardCaptureDeviceTestsVixen.Graphics.Golden.Tests
• SurfaceCardIndexVixen.Rendering.SurfaceCache
• TracedCardCaptureVixen.Rendering.SurfaceCache