IrradianceCubeCapture

Remarks

The piece that was owed. CapturedIrradianceFiller turns a cube into four coefficients and is checked against arithmetic with nothing rendered; this is what produces the cube, and until it existed doc 19 § 7's promise to WebGL2 — the same lighting model at a different update rate — was stated rather than true, because a target with no compute has no other way to fill a probe.

Six 90° frusta from Cube, which is not a coincidence. Direction is derived from that same matrix by unprojecting it, so the direction a projected texel came from and the direction the projection asks about are the same function evaluated twice rather than two conventions that have to be kept in step. A capture that renders with one convention and integrates with another comes back mirrored, which still looks like an environment.

It draws nothing itself. What a probe sees is the scene shaded — and how a project shades is a pipeline decision, not this type's. So the caller supplies a DrawFace, and doc 19's bounce iteration is the same callback shading with the field's previous answer: a source that reads the field produces a second bounce by being called twice.

⚠ Two-sided rasterisation is the caller's to arrange, and it matters. A probe inside a closed room sees the room's inside faces, which are back faces to a camera standing in it. Culled away, the room is invisible and the probe reports an unobstructed sky — the brightest possible wrong answer, and the one Validity is then unable to catch, because a probe that sees nothing looks exactly like a probe in the open.

Fields and properties (10)

• public static RenderOutput Output

  The attachments a face is rendered into, for whoever builds the pipelines.

• public int Size

  How many texels across one face is.

• public float Range

  How far a face looks before it stops seeing, which is its far plane.

• public float Near

  Its near plane.

• public Color4 Sky

  What a direction that hit nothing sees.

• public float MinimumDistance

  How near a hit has to be before it means "this probe is inside something".

• public Vector3 SunDirection

  Which way the sun is, in world space.

• public float SunRadius

  How wide a cone the sun tap averages over, in radians.

• public int Captures

  How many captures have been recorded.

• public bool IsCreated

  Whether the textures exist yet.

Methods (4)

• public IrradianceCubeCapture(IGraphicsDevice device)

  Creates a capture on a device. Nothing is allocated until the first record.

• public void Record(ICommandList commands, Vector3 position, IrradianceCubeCapture.DrawFace draw)

  Records the six passes that capture one probe's surroundings.

• public bool TryRead(out IrradianceCapture capture)

  Turns the last recorded capture into the three numbers a probe wants.

• public void Dispose()

  Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

Used by (3)

• IrradianceBounceDeviceTestsVixen.Graphics.Golden.Tests
• IrradianceCaptureDeviceTestsVixen.Graphics.Golden.Tests
• RenderedIrradianceCapturesVixen.Rendering