#include <MPxHardwareShader.h>

Class Description

Base class for user defined hardware shaders.

MPxHardwareShader allows the creation of user-defined hardware shaders. A hardware shader allows the plug-in writer to control the on-screen display of an object in Maya.

You must derive a hardware shader node from MPxHardwareShader for it to have any affect on the on-screen display at all. In addition to their affect on the on-screen display of objects, hardware shaders function as surface shader nodes. This allows you to connect any shading network up to the hardware shader's outColor attribute to handle the shading during a software render.

To create a working hardware shader, derive from this class and override the render() and optionally the populateRequirements() methods. The other methods of the parent class MPxNode may also be overridden to perform dependency node capabilities.

NOTE: Plug-in hardware shaders are fully supported for polygonal mesh shapes. NURBS surfaces are only supported in the High Quality Interactive viewport and Hardware Renderer.

Examples:: customTextureShader/customTextureShader.h, D3DViewportRenderer/D3DViewportRenderer.cpp, dx11Shader/dx11Shader.h, DX11ViewportRenderer/DX11ViewportRenderer.cpp, glslShader/GLSLShader.h, hlslShader/hlslShader.h, and vp2BlinnShader/vp2BlinnShader.h.

Inheritance diagram for MPxHardwareShader:

Classes
struct	RenderParameters
	Provides information on how to render the image. More...

struct	ShaderContext
	Provides contextual information about the current invocation of the shader. More...

Public Types
enum	TransparencyOptions { kIsTransparent = 0x0001, kNoTransparencyFrontBackCull = 0x0002, kNoTransparencyPolygonSort = 0x0004 }
	Transparency option bitmasks. More...

Public Types inherited from MPxNode
enum	Type { kDependNode, kLocatorNode, kDeformerNode, kManipContainer, kSurfaceShape, kFieldNode, kEmitterNode, kSpringNode, kIkSolverNode, kHardwareShader, kHwShaderNode, kTransformNode, kObjectSet, kFluidEmitterNode, kImagePlaneNode, kParticleAttributeMapperNode, kCameraSetNode, kConstraintNode, kManipulatorNode, kMotionPathNode, kClientDeviceNode, kThreadedDeviceNode, kAssembly, kSkinCluster, kGeometryFilter, kBlendShape, kLast }
	Defines the type of node. More...

enum	SchedulingType { kParallel, kSerial, kGloballySerial, kUntrusted, kDefaultScheduling = kSerial }
	Defines the degree of parallelism of a node. More...

Public Member Functions
	MPxHardwareShader ()
	Class constructor.

virtual	~MPxHardwareShader ()
	Class destructor.

virtual MPxNode::Type	type () const
	This method returns the type of the node. More...

MStatus	setVaryingParameters (const MVaryingParameterList &parameters, bool remapCurrentValues=true, MDagModifier *dagModifier=NULL)
	Call this method to set the list of varying parameters this shader uses. More...

MStatus	setUniformParameters (const MUniformParameterList &parameters, bool remapCurrentValues=true, MDagModifier *dagModifier=NULL)
	Call this method to set the list of uniform parameters this shader uses. More...

virtual MStatus	render (MGeometryList &iterator)
	Override this method to render geometry using your hardware shader. More...

virtual unsigned int	transparencyOptions ()
	This method returns transparency options for usage as hints for Maya's internal draw during a given rendering pass. More...

virtual const MRenderProfile &	profile ()
	Override this method to specify the renderers your shader supports. More...

virtual MStatus	populateRequirements (const MPxHardwareShader::ShaderContext &context, MGeometryRequirements &requirements)
	This method is not available in Python. More...

virtual MStatus	getAvailableImages (const MPxHardwareShader::ShaderContext &context, const MString &uvSetName, MStringArray &imageNames)
	This method is not available in Python. More...

virtual MStatus	renderImage (const MPxHardwareShader::ShaderContext &context, const MString &imageName, floatRegion region, int &imageWidth, int &imageHeight)
	This method is not available in Python. More...

virtual MStatus	renderImage (const MPxHardwareShader::ShaderContext &context, const MString &imageName, floatRegion region, const MPxHardwareShader::RenderParameters &parameters, int &imageWidth, int &imageHeight)
	This method is not available in Python. More...

virtual MStatus	renderImage (const MPxHardwareShader::ShaderContext &context, MHWRender::MUIDrawManager &uiDrawManager, const MString &imageName, floatRegion region, const MPxHardwareShader::RenderParameters &parameters, int &imageWidth, int &imageHeight)
	This method is not available in Python. More...

virtual MStatus	renderSwatchImage (MImage &image)
	If the shader specifies to override swatch rendering, then this method must be overridden in order to draw anything into a swatch. More...

Public Member Functions inherited from MPxNode
	MPxNode ()
	Constructor. More...

virtual	~MPxNode ()
	Destructor.

virtual void	postConstructor ()
	Post constructor. More...

virtual MStatus	compute (const MPlug &plug, MDataBlock &dataBlock)
	This method should be overridden in user defined nodes. More...

virtual bool	getInternalValueInContext (const MPlug &plug, MDataHandle &dataHandle, MDGContext &ctx)
	This method is overridden by nodes that store attribute data in some internal format. More...

virtual bool	setInternalValueInContext (const MPlug &plug, const MDataHandle &dataHandle, MDGContext &ctx)
	This method is overridden by nodes that store attribute data in some internal format. More...

virtual bool	getInternalValue (const MPlug &plug, MDataHandle &dataHandle)
	This method is obsolete. More...

virtual bool	setInternalValue (const MPlug &plug, const MDataHandle &dataHandle)
	This method is obsolete. More...

virtual int	internalArrayCount (const MPlug &plug, const MDGContext &ctx) const
	This method is overridden by nodes that have internal array attributes which are not stored in Maya's datablock. More...

virtual void	copyInternalData (MPxNode *)
	This method is overridden by nodes that store attribute data in some internal format. More...

virtual MStatus	legalConnection (const MPlug &plug, const MPlug &otherPlug, bool asSrc, bool &isLegal) const
	This method allows you to check for legal connections being made to attributes of this node. More...

virtual MStatus	legalDisconnection (const MPlug &plug, const MPlug &otherPlug, bool asSrc, bool &isLegal) const
	This method allows you to check for legal disconnections being made to attributes of this node. More...

virtual MStatus	setDependentsDirty (const MPlug &plug, MPlugArray &plugArray)
	This method can be overridden in user defined nodes to specify which plugs should be set dirty based upon an input plug {plugBeingDirtied} which Maya is marking dirty. More...

virtual MStatus	preEvaluation (const MDGContext &context, const MEvaluationNode &evaluationNode)
	Prepare a node's internal state for threaded evaluation. More...

virtual MStatus	postEvaluation (const MDGContext &context, const MEvaluationNode &evaluationNode, PostEvaluationType evalType)
	Clean up node's internal state after threaded evaluation. More...

virtual SchedulingType	schedulingType () const
	When overridden this method controls the degree of parallelism supported by the node during threaded evaluation. More...

virtual MStatus	connectionMade (const MPlug &plug, const MPlug &otherPlug, bool asSrc)
	This method gets called when connections are made to attributes of this node. More...

virtual MStatus	connectionBroken (const MPlug &plug, const MPlug &otherPlug, bool asSrc)
	This method gets called when connections are broken with attributes of this node. More...

virtual MStatus	dependsOn (const MPlug &plug, const MPlug &otherPlug, bool &depends) const
	This method may be overridden by the user defined node. More...

virtual bool	isPassiveOutput (const MPlug &plug) const
	This method may be overridden by the user defined node if it wants to provide output attributes which do not prevent value modifications to the destination attribute. More...

virtual MStatus	shouldSave (const MPlug &plug, bool &isSaving)
	This method may be overridden by the user defined node. More...

virtual MPlug	passThroughToOne (const MPlug &plug) const
	This method may be overridden by nodes that have a one-to-one relationship between an input attribute and a corresponding output attribute. More...

virtual bool	passThroughToMany (const MPlug &plug, MPlugArray &plugArray) const
	This method is overridden by nodes that want to control the traversal behavior of some Maya search algorithms which traverse the history/future of shape nodes looking for directly related nodes. More...

virtual bool	isAbstractClass () const
	Override this class to return true if this node is an abstract node. More...

virtual MStringArray	getFilesToArchive (bool shortName=false, bool unresolvedName=false, bool markCouldBeImageSequence=false) const
	Use this method to return all external files used by this node. More...

virtual void	getExternalContent (MExternalContentInfoTable &table) const
	Returns the external content (files) that this node depends on. More...

bool	addExternalContentForFileAttr (MExternalContentInfoTable &table, const MObject &attr) const
	Adds content info to the specified table from a file path attribute. More...

bool	setExternalContentForFileAttr (const MObject &attr, const MExternalContentLocationTable &table)
	Sets content info in the specified attribute from the table. More...

virtual void	setExternalContent (const MExternalContentLocationTable &table)
	Changes the location of external content in batch. More...

virtual MTypeId	typeId () const
	Returns the TYPEID of this node. More...

virtual MString	typeName () const
	Returns the type name of this node. More...

virtual MString	name () const
	Returns the name of this particular instance of this class. More...

virtual MObject	thisMObject () const
	Returns the MObject associated with this user defined node. More...

virtual MStatus	setExistWithoutInConnections (bool flag)
	This method specifies whether or not the node can exist without input connections. More...

virtual bool	existWithoutInConnections (MStatus *ReturnStatus=NULL) const
	Determines whether or not this node can exist without input connections. More...

virtual MStatus	setExistWithoutOutConnections (bool flag)
	This method specifies whether or not the node can exist without output connections. More...

virtual bool	existWithoutOutConnections (MStatus *ReturnStatus=NULL) const
	Determines whether or not this node can exist without output connections. More...

Static Public Member Functions
static MPxHardwareShader *	getHardwareShaderPtr (MObject &object)
	This is a static convenience method to be able to get an MPxHardwareShader from an MObject provided by a swatch generator class (Class derived from MSwatchRenderRegister). More...

static MString	findResource (const MString &name, const MString &shaderPath, MStatus *status=NULL)
	This is a static utility to find the full path to a shader resource (typically a texture). More...

static const char *	className ()
	Returns the name of this class. More...

Static Public Member Functions inherited from MPxNode
static MStatus	addAttribute (const MObject &attr)
	This method adds a new attribute to a user defined node type during the type's initialization. More...

static MStatus	inheritAttributesFrom (const MString &parentClassName)
	This method allows a class of plugin node to inherit all of the attributes of a second class of plugin node. More...

static MStatus	attributeAffects (const MObject &whenChanges, const MObject &isAffected)
	This method specifies that a particular input attribute affects a specific output attribute. More...

static const char *	className ()
	Returns the name of this class. More...

Static Public Attributes
static MObject	outColor
	output color value

static MObject	outColorR
	output color red

static MObject	outColorG
	output color green

static MObject	outColorB
	output color blue

Static Public Attributes inherited from MPxNode
static MObject	message
	message attribute

static MObject	isHistoricallyInteresting
	is historically interesting attribute

static MObject	caching
	caching attribute

static MObject	state
	state attribute

static MObject	frozen
	frozen attribute

Additional Inherited Members
Protected Member Functions inherited from MPxNode
virtual MDataBlock	forceCache (MDGContext &ctx=MDGContext::fsNormal)
	USE _forceCache() IN SCRIPT. More...

virtual void	setMPSafe (bool flag)
	USE _setMPSafe() IN SCRIPT. More...

virtual MStatus	setDoNotWrite (bool flag)
	USE _setDoNotWrite() IN SCRIPT. More...

virtual bool	doNotWrite (MStatus *ReturnStatus=NULL) const
	USE _doNotWrite() IN SCRIPT. More...

Member Enumeration Documentation

enum TransparencyOptions

Transparency option bitmasks.

Enumerator
kIsTransparent	When set means draw transparent.
kNoTransparencyFrontBackCull	When set means ignore front back cull.
kNoTransparencyPolygonSort	When set means ignore polygon sorting.

Member Function Documentation

MPxNode::Type type ( ) const

virtual

This method returns the type of the node.

This method should not be overridden by the user. It will return MPxNode::kHardwareShader.

Returns: The type of node

Reimplemented from MPxNode.

MStatus setVaryingParameters	(	const MVaryingParameterList &	parameters,
		bool	remapCurrentValues = `true`,
		MDagModifier *	dagModifier = `NULL`
	)

Call this method to set the list of varying parameters this shader uses.

Once set, you can use these parameters directly to access geometry data for surfaces being shaded. When using this method to manage shader varying parameters, there is no need to override populateRequirements or handle the node interface as Maya will handle parameter setup, presentation and configuration for you.

It is important to call this method whenever the shader parameters are modified (including at load time).

This is an optional method - shader implementations are still free to manage geometry parameters independently if they wish.

Parameters

[in]	parameters	the list of varying parameters for this shader
[in]	remapCurrentValues	if true (the default), Maya will attempt to initialise the value of new parameters based on any equivalently named parameters that currently exist on the node. Otherwise, the parameters will be setup using default values. Unless you wish to forcibly reset parameter values, the default value of true should be used.
[in]	dagModifier	an optional DG modifier to use when managing the attributes used to represent the geometry parameters on this shader.

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An error has occurred.

MStatus setUniformParameters	(	const MUniformParameterList &	parameters,
		bool	remapCurrentValues = `true`,
		MDagModifier *	dagModifier = `NULL`
	)

Call this method to set the list of uniform parameters this shader uses.

Once set, you can use these parameters to access the cached values of shader parameters, including testing when the value has been updated (to minimise the shader state changes). When using this method to manage uniform parameters, Maya will handle the underlyintg attributes, serialization and user interface for you.

It is important to call this method whenever the shader parameters are modified (including at load time).

This is an optional method - shader implementations are still free to manage uniform (i.e. shader-level) parameters independently if they wish.

Parameters

[in]	parameters	the list of uniform parameters for this shader
[in]	remapCurrentValues	if true (the default), Maya will attempt to initialise the value of new parameters based on any equivalently named parameters that currently exist on the node. Otherwise, the parameters will be setup using default values. Unless you wish to forcibly reset parameter values, the default value of true should be used.
[in]	dagModifier	an optional DG modifier to use when managing the attributes used to represent the geometry parameters on this shader.

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An error has occurred.

MStatus render ( MGeometryList & iterator )

virtual

Override this method to render geometry using your hardware shader.

It is important to note that you can only access surface data (e.g. uv sets) that you specified in populateRequirements. Any data you did not ask for is unlikely to be available in the geometry cache passed to you.

For example:

for( ; !iter.isDone(); iter.next())
{
    MGeometry& geometry = iter.geometry( MGeometryList::kMatrices | MGeometryList::kCulling);
    glVertexPointer( 3, GL_FLOAT, 0, geometry.position().data());
    glNormalPointer( GL_FLOAT, 0, geometry.normal().data());
    MGeometryPrimitive primitives = geometry.primitiveArray( 0);
    glDrawElements( GL_TRIANGLES, primitives.elementCount(), GL_UNSIGNED_INT, primitives.data());
}

Parameters

[in] iterator an iterator containing the geometry items you need to render.

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An error has occurred.

Examples:: customTextureShader/customTextureShader.h, dx11Shader/dx11Shader.h, glslShader/GLSLShader.h, and hlslShader/hlslShader.h.

unsigned int transparencyOptions ( )

virtual

This method returns transparency options for usage as hints for Maya's internal draw during a given rendering pass.

Parameters are returned via an integer containing masked out bits. By default the mask is set to 0, meaning that the drawing should be treated as regular opaque object drawing. This will generally mean one call per draw pass.

Options to control transparency are specified by returning one or more masks specified by the TransparencyOptions enumeration :

kIsTransparent : Draw as a transparent object. If no transparency overrides are specified, then control of how to draw during a given pass is determined internally by Maya's refresh algorithm, and options the user can set per modelling viewport.
kNoTransparencyFrontBackCull : When kisTransparent is set and this flag is set, do not perform transparency drawing using the internal 2-pass front-face + back-face culling algorithm.
kNoTransparencyPolygonSort : When kisTransparent is set and this flag is set, do not perform transparency drawing using the internal 2-pass drawing of back-to-front sorted triangles.

Note : Setting the "hasTransparency()" method to true will override this method. This is for backward compatibility with behaviour on existing hardware shader nodes. It is recommended that shaders use the "transparencyOptions()" override, and not longer use the older "hasTransparency()" override from their shader classes.

Returns: Integer containing the appropriate options set via masks.

Examples:: hlslShader/hlslShader.h.

const MRenderProfile & profile ( )

virtual

Override this method to specify the renderers your shader supports.

If this method is not overridden, Maya will assume your shader supports only Maya's iternal OpenGL based renderer.

Note that this method is called inside the rendering loop and as such, you should make this method as fast as possible - typically just returning a static/precalculated value.

Returns: A reference to the render profile for this Shader. Your shader class should create this once (usually for the whole class) and return the same object each time this method is called.

Examples:: D3DViewportRenderer/D3DViewportRenderer.cpp, dx11Shader/dx11Shader.h, DX11ViewportRenderer/DX11ViewportRenderer.cpp, glslShader/GLSLShader.h, hlslShader/hlslShader.h, and vp2BlinnShader/vp2BlinnShader.h.

MStatus populateRequirements	(	const MPxHardwareShader::ShaderContext &	context,
		MGeometryRequirements &	requirements
	)

virtual

This method is not available in Python.

Override this method to let Maya know what surface data (e.g.

positions, normals, uv sets, tangents, binormals, etc) your shader needs in order to render the specified geometry. This is the only data your shader will be able to access when rendering the geometry. For example, if your shader needs uv set "foo" to render a texture, you must include that here before trying to use it in your render method.

The default implementation (in MPxHardwareShader) sets up the requirements for any public MVaryingParameters you have configured on this shader. If you override this method and use MVaryingParameters, you should make a call into the base class method as part of your implementation of the method.

Parameters

[in]	context	Context of the draw request (e.g. the surface being shaded, shading engine making the request).
[out]	requirements	The requirements structure you need to fill in.

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An error has occurred.

MStatus getAvailableImages	(	const MPxHardwareShader::ShaderContext &	context,
		const MString &	uvSetName,
		MStringArray &	imageNames
	)

virtual

This method is not available in Python.

Maya will call this method to get your shader's list of images which are available for use in the UV editor for the UV set specified.

Typically, this list will include one entry for each texture using the specified UV set, however, your shader is free to return as many images as you wish (for example, blending between two textures, texture alpha masks, artificially shaded views of bump/normal maps, etc). Your shader's renderImage() method will be used to render the images themselves.

Parameters

[in]	context	Context of the draw request (e.g. the surface being shaded, shading engine making the request).
[in]	uvSetName	Name of a UV set the channel list should be filtered against.
[out]	imageNames	Array in which to return the names of the images this shader defines which are valid for the uvSetName specified.

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An error has occurred.
MS::kNotImplemented Use the default behaviour.

Examples:: dx11Shader/dx11Shader.h, glslShader/GLSLShader.h, and hlslShader/hlslShader.h.

MStatus renderImage	(	const MPxHardwareShader::ShaderContext &	context,
		const MString &	imageName,
		floatRegion	region,
		int &	imageWidth,
		int &	imageHeight
	)

virtual

This method is not available in Python.

This method is obsolete.

Deprecated:: Use renderImage() that provides RenderParameters instead.

This method allows you to to render the background image used for this shader in the UV editor. The image requested will be one of the image names returned by your shader's getAvailableImages() method.

The implementation must return the dimensions of the image in the 'imageWidth' and 'imageHeight' parameters so that Maya can perform pixel snapping and other resolution-dependent operations.

The implementation can assume OpenGL context, model view projection matrix, and texture transformations have already been set. A default color of white will be set, however you are free to change this. The magnification filter will be set to either point or bilinear based on user configuration and should not be modified. The values of GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T are undefined on entry, and your implementation is responsible for setting them to appropriate values (e.g. GL_REPEAT).

The arguments contain the name of the image to render, and the vertex and texture coordinate values to use at each corner of the rectangular image being rendered. Your implementation is responsible for restoring the original the value of any OpenGL state that is modified.

For example:

glPushAttrib( <GL bits your shader modifies> );
glPushClientAttrib( GL_CLIENT_VERTEX_ARRAY_BIT);
... setup material here ...
glBegin( GL_QUADS);
glTexCoord2f(region[0][0], region[0][1]);
glVertex2f(region[0][0], region[0][1]);
glTexCoord2f(region[0][0], region[1][1]);
glVertex2f(region[0][0], region[1][1]);
glTexCoord2f(region[1][0], region[1][1]);
glVertex2f(region[1][0], region[1][1]);
glTexCoord2f(region[1][0], region[0][1]);
glVertex2f(region[1][0], region[0][1]);
glEnd();
glPopAttrib();
glPopClientAttrib();

Parameters

[in]	context	Context of the draw request (e.g. the surface being shaded, shading engine making the request).
[in]	imageName	Name of the image to render. This corresponds to one of the image names returned by your shader's getAvailableImages() method.
[in]	region	Rectangular region to be rendered. The values of this parameter should be used to populate the vertex and texture coordinates of the rectangle being rendered.
[out]	imageWidth	Native width (e.g. texture pixel width) of the image. This should be for the entire image, not just the portion within 'region'.
[out]	imageHeight	Native height (e.g. texture pixel height) of the image. This should be for the entire image, not just the portion within 'region'.

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An error has occurred.

Examples:: dx11Shader/dx11Shader.h, glslShader/GLSLShader.h, and hlslShader/hlslShader.h.

MStatus renderImage	(	const MPxHardwareShader::ShaderContext &	context,
		const MString &	imageName,
		floatRegion	region,
		const MPxHardwareShader::RenderParameters &	parameters,
		int &	imageWidth,
		int &	imageHeight
	)

virtual

This method is not available in Python.

This method allows you to to render the background image used for this shader in the UV editor in viewport 2.0.

The image requested will be one of the image names returned by your shader's getAvailableImages() method.

The implementation must return the dimensions of the image in the 'imageWidth' and 'imageHeight' parameters so that Maya can perform pixel snapping and other resolution-dependent operations.

The implementation can assume OpenGL context, model view projection matrix, and texture transformations have already been set. A default color of white will be set, however you are free to change this. The magnification filter will be set to either point or bilinear based on user configuration and should not be modified. The values of GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T are undefined on entry, and your implementation is responsible for setting them to appropriate values (e.g. GL_REPEAT).

The arguments contain the name of the image to render, and the vertex and texture coordinate values to use at each corner of the rectangular image being rendered. Your implementation is responsible for restoring the original the value of any OpenGL state that is modified.

For example:

glPushAttrib( <GL bits your shader modifies> );
glPushClientAttrib( GL_CLIENT_VERTEX_ARRAY_BIT);
... setup material here ...
glBegin( GL_QUADS);
glTexCoord2f(region[0][0], region[0][1]);
glVertex2f(region[0][0], region[0][1]);
glTexCoord2f(region[0][0], region[1][1]);
glVertex2f(region[0][0], region[1][1]);
glTexCoord2f(region[1][0], region[1][1]);
glVertex2f(region[1][0], region[1][1]);
glTexCoord2f(region[1][0], region[0][1]);
glVertex2f(region[1][0], region[0][1]);
glEnd();
glPopAttrib();
glPopClientAttrib();

Parameters

[in]	context	Context of the draw request (e.g. the surface being shaded, shading engine making the request).
[in]	imageName	Name of the image to render. This corresponds to one of the image names returned by your shader's getAvailableImages() method.
[in]	region	Rectangular region to be rendered. The values of this parameter should be used to populate the vertex and texture coordinates of the rectangle being rendered.
[in]	parameters	Additional parameters on how to render the image. The values reflect the image settings of the UV editor.
[out]	imageWidth	Native width (e.g. texture pixel width) of the image. This should be for the entire image, not just the portion within 'region'.
[out]	imageHeight	Native height (e.g. texture pixel height) of the image. This should be for the entire image, not just the portion within 'region'.

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An error has occurred.

MStatus renderImage	(	const MPxHardwareShader::ShaderContext &	context,
		MHWRender::MUIDrawManager &	uiDrawManager,
		const MString &	imageName,
		floatRegion	region,
		const MPxHardwareShader::RenderParameters &	parameters,
		int &	imageWidth,
		int &	imageHeight
	)

virtual

This method is not available in Python.

This method allows you to to render the background image used for this shader in the UV editor.

The image requested will be one of the image names returned by your shader's getAvailableImages() method.

The implementation must return the dimensions of the image in the 'imageWidth' and 'imageHeight' parameters so that Maya can perform pixel snapping and other resolution-dependent operations.

Parameters

[in]	context	Context of the draw request (e.g. the surface being shaded, shading engine making the request).
[in]	uiDrawManager	The UI draw manager, it can be used to draw some simple geometry
[in]	imageName	Name of the image to render. This corresponds to one of the image names returned by your shader's getAvailableImages() method.
[in]	region	Rectangular region to be rendered. The values of this parameter should be used to populate the vertex and texture coordinates of the rectangle being rendered.
[in]	parameters	Additional parameters on how to render the image. The values reflect the image settings of the UV editor.
[out]	imageWidth	Native width (e.g. texture pixel width) of the image. This should be for the entire image, not just the portion within 'region'.
[out]	imageHeight	Native height (e.g. texture pixel height) of the image. This should be for the entire image, not just the portion within 'region'.

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An error has occurred.

MStatus renderSwatchImage ( MImage & image )

virtual

If the shader specifies to override swatch rendering, then this method must be overridden in order to draw anything into a swatch.

The shader will only draw a swatch if it has been registered to do so, by providing a valid classification during MFnPlugin::registerNode(). The shader should provide a classification that defines a swatch rendering node such as : "shader/surface/utility/:drawdb/shader/surface/myCustomShader:swatch/myCustomShaderSwatchGenerator" and have "myCustomShaderSwatchGenerator" registered has a swatch renderer : MSwatchRenderRegister::registerSwatchRender("myCustomShaderSwatchGenerator", MHWShaderSwatchGenerator::createObj );

The default implementation is to draw nothing. The basic logic to draw a swatch is as follows:

Determine the size of the swatch required. This is the dimensions of the MImage passed in as an argument. The pixels for the MImage will have been pre-allocated. The format of the pixels is 32-bit R,G,B,A, with 8-bits per channel.
Either use an offscreen "swatch context" provided to you or use your own offscreen context. The provided context is available via MHardwareRenderer::makeSwatchContextCurrent(). Note that the swatch context may be smaller than the desired image size. In this case the rendering dimensions will be clamped.
Either use swatch geometry provided to you, or use your own swatch geometry. The provided geometry is available via MHardwareRenderer::referenceDefaultGeometry(). The possible "default" geometries are either a sphere, cube or plane.
Either use the provided default light and camera or set up your own. MHardwareRenderer provides methods to retrieve the defaults.
Read back the swatch context into the provided MImage. The convenience method MHardwareRenderer::readSwatchContextPixels() can be used. By default the format of the MImage and the swatch context are the same, so the user does not need to worry about this. The context will read into the pre-allocated MImage pixels.
Unreference any swatch geometry used for rendering using MHardwareRenderer::dereferenceGeometry().

Parameters

[in,out] image Image object to which this method must write the rendered swatch. On input the image's dimensions are already set and pixel storage already allocated.

Returns: Status code

Status Codes:

MS::kNotImplemented : No rendering will occur.

Examples:: dx11Shader/dx11Shader.h, glslShader/GLSLShader.h, hlslShader/hlslShader.h, and vp2BlinnShader/vp2BlinnShader.h.

MPxHardwareShader * getHardwareShaderPtr ( MObject & object )

static

This is a static convenience method to be able to get an MPxHardwareShader from an MObject provided by a swatch generator class (Class derived from MSwatchRenderRegister).

Parameters

[in] object The object to examine.

Returns: A pointer to an MPxHardwareShader. If the method failed for any reason then a 0 (null) will be returned.

Examples:: D3DViewportRenderer/D3DViewportRenderer.cpp, dx11Shader/dx11ShaderOverride.cpp, DX11ViewportRenderer/DX11ViewportRenderer.cpp, glslShader/GLSLShaderOverride.cpp, and vp2BlinnShader/vp2BlinnShader.cpp.

MString findResource	(	const MString &	name,
		const MString &	shaderPath,
		MStatus *	status = `NULL`
	)

static

This is a static utility to find the full path to a shader resource (typically a texture).

This method will search the list of paths in the MAYA_HW_SHADER_RESOURCE_PATH environment variable, resolving relative paths based on the directory containing the shader.

Parameters

[in]	name	The name of the resource to look for (e.g. "normals.dds")
[in]	shaderPath	The full path to the current shader (e.g. "C:/shaders/myshader.fx")
[in]	status	If a pointer to a status is provided, the status will be set to MS::kSuccess if the resource was found, and MS::kFailure otherwise.

Returns: The full path of the resource (e.g. "C:/shaders/textures/normals.dds")

const char * className ( )

static

Returns the name of this class.

Returns: The name of this class.

The documentation for this class was generated from the following files:

MPxHardwareShader.h
MPxHardwareShader.cpp

MPxHardwareShader Class Reference

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