Package org.sunflow.core

## Interface Shader

- All Superinterfaces:
    `RenderObject`
  All Known Implementing Classes:
    `AmbientOcclusionShader`, `AnisotropicWardShader`, `ConstantShader`, `CornellBox`, `DiffuseShader`, `GlassShader`, `Hair`, `IDShader`, `ImageBasedLight`, `MirrorShader`, `NormalShader`, `PhongShader`, `PrimIDShader`, `QuickGrayShader`, `ShinyDiffuseShader`, `SimpleShader`, `SphereLight`, `SunSkyLight`, `TexturedAmbientOcclusionShader`, `TexturedDiffuseShader`, `TexturedPhongShader`, `TexturedShinyDiffuseShader`, `TexturedWardShader`, `TriangleMeshLight`, `UberShader`, `UVShader`, `ViewCausticsShader`, `ViewGlobalPhotonsShader`, `ViewIrradianceShader`, `WireframeShader`

      public interface Shader
      extends RenderObject

  A shader represents a particular light-surface interaction.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `Color` | `getOpacity​(ShadingState state)` | Returns how much light is blocked by this shader.
    `Color` | `getRadiance​(ShadingState state)` | Gets the radiance for a specified rendering state.
    `boolean` | `isOpaque()` | Returns `true` if this shader is fully opaque.
    `void` | `scatterPhoton​(ShadingState state, Color power)` | Scatter a photon with the specied power.

    - ### Methods inherited from interface org.sunflow.core.RenderObject

      `update`

- - ### Method Detail

    - #### getRadiance

          Color getRadiance​(ShadingState state)

      Gets the radiance for a specified rendering state. When this method is called, you can assume that a hit has been registered in the state and that the hit surface information has been computed.
      Parameters:
        `state` - current render state
      Returns:
        color emitted or reflected by the shader

    - #### scatterPhoton

          void scatterPhoton​(ShadingState state,
                             Color power)

      Scatter a photon with the specied power. Incoming photon direction is specified by the ray attached to the current render state. This method can safely do nothing if photon scattering is not supported or relevant for the shader type.
      Parameters:
        `state` - current state
        `power` - power of the incoming photon.

    - #### isOpaque

          boolean isOpaque()

      Returns `true` if this shader is fully opaque. This gives a quick way to find out if a shader needs further processing when hit by a shadow ray.

    - #### getOpacity

          Color getOpacity​(ShadingState state)

      Returns how much light is blocked by this shader.