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PerInstanceColorAppearance

new Cesium.PerInstanceColorAppearance(options)

An appearance for GeometryInstance instances with color attributes. This allows several geometry instances, each with a different color, to be drawn with the same Primitive as shown in the second example below.
Name Type Description
options object optional Object with the following properties:
Name Type Default Description
flat boolean false optional When true, flat shading is used in the fragment shader, which means lighting is not taking into account.
faceForward boolean !options.closed optional When true, the fragment shader flips the surface normal as needed to ensure that the normal faces the viewer to avoid dark spots. This is useful when both sides of a geometry should be shaded like WallGeometry.
translucent boolean true optional When true, the geometry is expected to appear translucent so PerInstanceColorAppearance#renderState has alpha blending enabled.
closed boolean false optional When true, the geometry is expected to be closed so PerInstanceColorAppearance#renderState has backface culling enabled.
vertexShaderSource string optional Optional GLSL vertex shader source to override the default vertex shader.
fragmentShaderSource string optional Optional GLSL fragment shader source to override the default fragment shader.
renderState object optional Optional render state to override the default render state.
Example:
// A solid white line segment
const primitive = new Cesium.Primitive({
  geometryInstances : new Cesium.GeometryInstance({
    geometry : new Cesium.SimplePolylineGeometry({
      positions : Cesium.Cartesian3.fromDegreesArray([
        0.0, 0.0,
        5.0, 0.0
      ])
    }),
    attributes : {
      color : Cesium.ColorGeometryInstanceAttribute.fromColor(new Cesium.Color(1.0, 1.0, 1.0, 1.0))
    }
  }),
  appearance : new Cesium.PerInstanceColorAppearance({
    flat : true,
    translucent : false
  })
});

// Two rectangles in a primitive, each with a different color
const instance = new Cesium.GeometryInstance({
  geometry : new Cesium.RectangleGeometry({
    rectangle : Cesium.Rectangle.fromDegrees(0.0, 20.0, 10.0, 30.0)
  }),
  attributes : {
    color : new Cesium.ColorGeometryInstanceAttribute(1.0, 0.0, 0.0, 0.5)
  }
});

const anotherInstance = new Cesium.GeometryInstance({
  geometry : new Cesium.RectangleGeometry({
    rectangle : Cesium.Rectangle.fromDegrees(0.0, 40.0, 10.0, 50.0)
  }),
  attributes : {
    color : new Cesium.ColorGeometryInstanceAttribute(0.0, 0.0, 1.0, 0.5)
  }
});

const rectanglePrimitive = new Cesium.Primitive({
  geometryInstances : [instance, anotherInstance],
  appearance : new Cesium.PerInstanceColorAppearance()
});

Members

static constant Cesium.PerInstanceColorAppearance.FLAT_VERTEX_FORMAT : VertexFormat

The VertexFormat that all PerInstanceColorAppearance instances are compatible with when PerInstanceColorAppearance#flat is true. This requires only a position attribute.

static constant Cesium.PerInstanceColorAppearance.VERTEX_FORMAT : VertexFormat

The VertexFormat that all PerInstanceColorAppearance instances are compatible with. This requires only position and normal attributes.
When true, the geometry is expected to be closed so PerInstanceColorAppearance#renderState has backface culling enabled. If the viewer enters the geometry, it will not be visible.
Default Value: false
When true, the fragment shader flips the surface normal as needed to ensure that the normal faces the viewer to avoid dark spots. This is useful when both sides of a geometry should be shaded like WallGeometry.
Default Value: true
When true, flat shading is used in the fragment shader, which means lighting is not taking into account.
Default Value: false

readonly fragmentShaderSource : string

The GLSL source code for the fragment shader.
This property is part of the Appearance interface, but is not used by PerInstanceColorAppearance since a fully custom fragment shader is used.
Default Value: undefined
The WebGL fixed-function state to use when rendering the geometry.

The render state can be explicitly defined when constructing a PerInstanceColorAppearance instance, or it is set implicitly via PerInstanceColorAppearance#translucent and PerInstanceColorAppearance#closed.

When true, the geometry is expected to appear translucent so PerInstanceColorAppearance#renderState has alpha blending enabled.
Default Value: true
The VertexFormat that this appearance instance is compatible with. A geometry can have more vertex attributes and still be compatible - at a potential performance cost - but it can't have less.

readonly vertexShaderSource : string

The GLSL source code for the vertex shader.

Methods

getFragmentShaderSource()string

Procedurally creates the full GLSL fragment shader source. For PerInstanceColorAppearance, this is derived from PerInstanceColorAppearance#fragmentShaderSource, PerInstanceColorAppearance#flat, and PerInstanceColorAppearance#faceForward.
Returns:
The full GLSL fragment shader source.
Creates a render state. This is not the final render state instance; instead, it can contain a subset of render state properties identical to the render state created in the context.
Returns:
The render state.
Determines if the geometry is translucent based on PerInstanceColorAppearance#translucent.
Returns:
true if the appearance is translucent.
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