Shader semantics supported by Viewport 2.0

The following semantics are recognized and supported for use with shaders in Viewport 2.0. They can be used when authoring full effects which are accessed as MShaderInstance objects using the MShaderManager class. They may also be applied to the parameters of fragments which are registered using MFragmentManager.

Note: The dx11Shader.mll and glslShader.mll plug-ins are both MPxShaderOverrides. Therefore, each must parse the effects to determine and bind the semantics manually. By comparison, both the fragment system and MShaderInstance do all this automatically; however, they are both also more restrictive.

The world co-ordinate system can be further divided into different locales, each with a different origin. A node can then be specified in any of these locales. This allows the node position to be made with greater precision than if it were defined in the world co-ordinate system.

All matrices that belong to the FrameLocale group are re-applied when the locale of a current node is different from the locale of a previous node. At render time, camera and lights are transformed into the current node's locale space so that the object, the camera, and the lights are all represented in the same local co-ordinate space and can be stored and represented with single precision floating point values.

Semantic Usage Type Group
World World transformation Matrix

Item FL

WorldTranspose World transformation, transposed Matrix

Item FL

WorldInverse World transformation, inverted Matrix

Item FL

WorldInverseTranspose World transformation, inverted and transposed Matrix

Item FL

PreviousWorld Previous world transformation Matrix Item
NextWorld Next world transformation Matrix Item
       
View View transformation Matrix FrameLocale
ViewTranspose View transformation, transposed Matrix FrameLocale
ViewInverse View transformation, inverted Matrix FrameLocale
ViewInverseTranspose View transformation, inverted and transposed Matrix FrameLocale
       
Projection Projection transformation Matrix Frame
ProjectionTranspose Projection transformation, transposed Matrix Frame
ProjectionInverse Projection transformation, inverted Matrix Frame
ProjectionInverseTranspose Projection transformation, inverted and transposed Matrix Frame

ProjectionZSense

Denotes whether the projection matrix flips the Z component of a point when transformed: if so, -1.0; otherwise 1.0. Float Frame
WorldView World-view transformation Matrix

Item FL

WorldViewTranspose World-view transformation, transposed Matrix

Item FL

WorldViewInverse World-view transformation, inverted Matrix

Item FL

WorldViewInverseTranspose World-view transformation, inverted and transposed Matrix

Item FL

WorldLocaleOrigin

Apply an offset to the locale transformation matrix to obtain the true (global) world transformation matrix.

Applying this offset can result in a lack of precision in cases where double precision is required to represent an accurate position in large coordinate systems.

Float3

FrameLocale

       
ViewProjection View-projection transformation Matrix FrameLocale
ViewProjectionTranspose View-projection transformation, transposed Matrix FrameLocale
ViewProjectionInverse View-projection transformation, inverted Matrix FrameLocale
ViewProjectionInverseTranspose View-projection transformation, inverted and transposed Matrix FrameLocale
PreviousViewProjection Previous view-projection transformation Matrix FrameLocale
       
WorldViewProjection World-view-projection transformation Matrix

Item FL

WorldViewProjectionTranspose World-view-projection transformation, transposed Matrix

Item FL

WorldViewProjectionInverse World-view-projection transformation, inverted Matrix

Item FL

WorldViewProjectionInverseTranspose World-view-projection transformation, inverted and transposed Matrix

Item FL

The following are MultiDraw versions of other semantics, used as alternates for rendering MultiDraw consolidation if MPxShaderOverride::supportsMultiDraw() is overridden to return true.

WorldMD MultiDraw array of World transformation Matrix[64]

Item FL

WorldTMD MultiDraw array of World transformation, transposed Matrix[64]

Item FL

WorldIMD MultiDraw array of World transformation, inverted Matrix[64]

Item FL

WorldITMD MultiDraw array of World transformation, inverted and transposed Matrix[64]

Item FL

WorldViewMD MultiDraw array of World-view transformation Matrix[64]

Item FL

WorldViewTMD MultiDraw array of World-view transformation, transposed Matrix[64]

Item FL

WorldViewIMD MultiDraw array of World-view transformation, inverted Matrix[64]

Item FL

WorldViewITMD MultiDraw array of World-view transformation, inverted and transposed Matrix[64]

Item FL

WorldViewProjMD MultiDraw array of World-view-projection transformation Matrix[64]

Item FL

WorldViewProjTMD MultiDraw array of World-view-projection transformation, transposed Matrix[64]

Item FL

WorldViewProjIMD MultiDraw array of World-view-projection transformation, inverted Matrix[64]

Item FL

WorldViewProjITMD MultiDraw array of World-view-projection transformation, inverted and transposed Matrix[64]

Item FL

ViewDirection World-space direction of the view (camera) Float3 FrameLocale
ViewPosition World-space position of the view (camera) Float3 FrameLocale
LocalViewer Denotes whether a local or non-local view direction is to be used Bool Frame
       
IsOrthoGraphic Denotes whether the projection matrix is orthographic Bool Frame
       
ViewportPixelSize Dimensions of the current viewport in pixels, width and height Float2 Frame
       
ClippingPlanes The coefficients of active clipping planes, one float4 per plane Float4 Array Clipping
ClippingPlaneCount The number of active clipping planes Int Clipping
NearClipPlane The camera’s near clipping plane Float Frame
       

Time

AnimationTime

Sas.Time.Now

Time in seconds

Note:

Only applicable to shading overrides created using an MPxShaderOverride. The MPxShaderOverride must support auto-binding of MUniformParameters to the shader uniform parameters.

That is, the MPxShaderOverride must create an MUniformParameter for each uniform parameter, retrieve each MUniformParameter value based on its associated semantic, and bind this value to the shader uniform parameter.

This is automatically done by the dx11Shader and glslShader plug-ins.

In addition, Time and Frame are only available when the effects file is loaded from the glslShader plug-in.

Float Frame

Frame

FrameNumber

Frame in frame units

Note:

Only applicable to shading overrides created using an MPxShaderOverride. The MPxShaderOverride must support auto-binding of MUniformParameters to the shader uniform parameters.

That is, the MPxShaderOverride must create an MUniformParameter for each uniform parameter, retrieve each MUniformParameter value based on its associated semantic, and bind this value to the shader uniform parameter.

This is automatically done by the dx11Shader and glslShader plug-ins.

Int Frame
       
AlphaTestFunction The alpha test comparison function

1 = Never

2 = Less

3 = Equal

4 = Less or Equal

5 = Greater

6 = Not Equal

7 = Greater or Equal

8 = Always

Int Alpha Test
AlphaTestReference The alpha test reference value, in the range of (0.0, 1.0) Float Alpha Test
       
RelativeViewportDimensions Specifies relative viewport dimensions Float2 Frame
       
MayaReceivesShadowOn Denotes whether the object receives shadows Bool Item
       
EnableXRayComp Denotes whether xray component mode is enabled Bool Frame
       
MayaViewportModes Viewport modes

0 = Does not contain bounding box

1 = Contains bounding box

Int Frame
       
FogEnabled Denotes whether hardware fog is enabled Bool Frame
FogMode Hardware fog falloff mode

0 = Linear

1 = Exponential

2 = Exponential-squared

Int Frame
FogStart Hardware fog start z-distance in view space Float Frame
FogEnd Hardware fog end z-distance in view space Float Frame
FogDensity Hardware fog density Float Frame
FogColor Hardware fog color Float4 Frame
Note: FL denotes that the semantic is also frame locale dependant.