C++ API Reference
volumeShader/volumeShader.cpp
#include <math.h>
#include <maya/MPxNode.h>
#include <maya/MIOStream.h>
#include <maya/MString.h>
#include <maya/MTypeId.h>
#include <maya/MPlug.h>
#include <maya/MDataBlock.h>
#include <maya/MDataHandle.h>
#include <maya/MFnNumericAttribute.h>
#include <maya/MFloatVector.h>
#include <maya/MFnPlugin.h>
//
// DESCRIPTION:
// Produces dependency graph node VolumeNode
//
// This node is an example of a volume shader. Volume shaders are used to apply color to specialized shapes
// associated with light sources called "light shapes". One such set of shapes is created by the Light Fog effect.
// The Light Fog effect can be assigned to any point or spot light through their respective Attribute Editors.
//
// The output attribute of the VolumeNode node is called "outColor". To use this shader, create a VolumeNode node and connect
// its output to the "volumeShader" input of a Shading Group. The shading group must be connected to a light shape.
//
class VolumeNode : public MPxNode
{
public:
VolumeNode();
~VolumeNode() override;
MStatus compute( const MPlug&, MDataBlock& ) override;
SchedulingType schedulingType() const override { return SchedulingType::kParallel; }
static void * creator();
static MStatus initialize();
static MTypeId id;
private:
static MObject aColor;
static MObject aInputValue;
static MObject aOutColor;
static MObject aOutTransparency;
static MObject aFarPointC;
static MObject aFarPointO;
static MObject aFarPointW;
static MObject aPointC;
static MObject aPointO;
static MObject aPointW;
static MObject aToggleCamera;
static MObject aToggleObject;
static MObject aToggleWorld;
static MObject aOutAlpha;
};
MTypeId VolumeNode::id( 0x81012 );
MObject VolumeNode::aColor ;
MObject VolumeNode::aInputValue;
MObject VolumeNode::aOutColor;
MObject VolumeNode::aOutTransparency;
MObject VolumeNode::aOutAlpha;
MObject VolumeNode::aFarPointC;
MObject VolumeNode::aFarPointO;
MObject VolumeNode::aFarPointW;
MObject VolumeNode::aPointC;
MObject VolumeNode::aPointO;
MObject VolumeNode::aPointW;
MObject VolumeNode::aToggleCamera;
MObject VolumeNode::aToggleObject;
MObject VolumeNode::aToggleWorld;
//
// DESCRIPTION:
VolumeNode::VolumeNode()
{
}
//
// DESCRIPTION:
VolumeNode::~VolumeNode()
{
}
//
// DESCRIPTION:
void* VolumeNode::creator()
{
return new VolumeNode();
}
//
// DESCRIPTION:
MStatus VolumeNode::initialize()
{
MFnNumericAttribute nAttr;
// Inputs
aColor = nAttr.createColor( "color", "c" );
CHECK_MSTATUS( nAttr.setKeyable( true ) );
CHECK_MSTATUS( nAttr.setStorable( true ) );
CHECK_MSTATUS( nAttr.setHidden(false) );
CHECK_MSTATUS( nAttr.setDefault(1.0f, 1.0f, 1.0f) );
aInputValue = nAttr.create( "distance", "d", MFnNumericData::kFloat);
CHECK_MSTATUS( nAttr.setMin(0.0f) );
CHECK_MSTATUS(nAttr.setMax(100000.0f) );
CHECK_MSTATUS( nAttr.setSoftMax(1000.0f) );
CHECK_MSTATUS( nAttr.setSoftMax(1000.0f) );
CHECK_MSTATUS( nAttr.setKeyable(true) );
CHECK_MSTATUS(nAttr.setStorable(true) );
CHECK_MSTATUS( nAttr.setDefault(1.0f) );
aToggleCamera = nAttr.create( "cameraSpace", "cs",
MFnNumericData::kBoolean);
CHECK_MSTATUS( nAttr.setKeyable(true) );
CHECK_MSTATUS( nAttr.setStorable(true) );
CHECK_MSTATUS( nAttr.setHidden(false) );
CHECK_MSTATUS( nAttr.setDefault(false) );
aToggleObject = nAttr.create( "objectSpace", "os",
MFnNumericData::kBoolean);
CHECK_MSTATUS( nAttr.setKeyable(true) );
CHECK_MSTATUS( nAttr.setStorable(true) );
CHECK_MSTATUS( nAttr.setHidden(false) );
CHECK_MSTATUS( nAttr.setDefault(false) );
aToggleWorld = nAttr.create( "worldSpace", "ws", MFnNumericData::kBoolean);
CHECK_MSTATUS(nAttr.setKeyable(true) );
CHECK_MSTATUS( nAttr.setStorable(true) );
CHECK_MSTATUS(nAttr.setHidden(false) );
CHECK_MSTATUS( nAttr.setDefault(true) );
aFarPointC = nAttr.createPoint("farPointCamera", "fc" );
CHECK_MSTATUS(nAttr.setStorable(false) );
CHECK_MSTATUS( nAttr.setHidden(true) );
CHECK_MSTATUS( nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(true) );
aFarPointO = nAttr.createPoint("farPointObj", "fo" );
CHECK_MSTATUS( nAttr.setStorable(false) );
CHECK_MSTATUS(nAttr.setHidden(true) );
CHECK_MSTATUS( nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(true) );
aFarPointW = nAttr.createPoint("farPointWorld", "fw" );
CHECK_MSTATUS( nAttr.setStorable(false) );
CHECK_MSTATUS( nAttr.setHidden(true) );
CHECK_MSTATUS(nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(true) );
aPointC = nAttr.createPoint("pointCamera", "p" );
CHECK_MSTATUS( nAttr.setStorable(false) );
CHECK_MSTATUS( nAttr.setHidden(true) );
CHECK_MSTATUS( nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(true) );
aPointO = nAttr.createPoint("pointObj", "po" );
CHECK_MSTATUS( nAttr.setStorable(false) );
CHECK_MSTATUS( nAttr.setHidden(true) );
CHECK_MSTATUS( nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(true) );
aPointW = nAttr.createPoint("pointWorld", "pw" );
CHECK_MSTATUS( nAttr.setStorable(false) );
CHECK_MSTATUS( nAttr.setHidden(true) );
CHECK_MSTATUS( nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(true) );
// Outputs
aOutColor = nAttr.createColor( "outColor", "oc" );
CHECK_MSTATUS( nAttr.setStorable(false) );
CHECK_MSTATUS( nAttr.setHidden(false) );
CHECK_MSTATUS( nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(false) );
aOutTransparency = nAttr.createColor( "outTransparency", "ot" );
CHECK_MSTATUS( nAttr.setStorable(false) );
CHECK_MSTATUS( nAttr.setHidden(false) );
CHECK_MSTATUS( nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(false) );
aOutAlpha = nAttr.create( "outAlpha", "oa", MFnNumericData::kFloat);
CHECK_MSTATUS( nAttr.setStorable(false) );
CHECK_MSTATUS( nAttr.setHidden(false) );
CHECK_MSTATUS( nAttr.setReadable(true) );
CHECK_MSTATUS( nAttr.setWritable(false) );
CHECK_MSTATUS( addAttribute(aColor) );
CHECK_MSTATUS( addAttribute(aInputValue) );
CHECK_MSTATUS( addAttribute(aFarPointC) );
CHECK_MSTATUS( addAttribute(aFarPointO) );
CHECK_MSTATUS( addAttribute(aFarPointW) );
CHECK_MSTATUS( addAttribute(aPointC) );
CHECK_MSTATUS( addAttribute(aPointO) );
CHECK_MSTATUS( addAttribute(aPointW) );
CHECK_MSTATUS( addAttribute(aToggleCamera) );
CHECK_MSTATUS( addAttribute(aToggleObject) );
CHECK_MSTATUS( addAttribute(aToggleWorld) );
CHECK_MSTATUS( addAttribute(aOutColor) );
CHECK_MSTATUS( addAttribute(aOutTransparency) );
CHECK_MSTATUS( addAttribute(aOutAlpha) );
CHECK_MSTATUS( attributeAffects(aColor, aOutColor) );
CHECK_MSTATUS( attributeAffects(aColor, aOutTransparency) );
CHECK_MSTATUS( attributeAffects(aFarPointC, aOutColor) );
CHECK_MSTATUS( attributeAffects(aFarPointO, aOutColor) );
CHECK_MSTATUS( attributeAffects(aFarPointW, aOutColor) );
CHECK_MSTATUS( attributeAffects(aPointC, aOutColor) );
CHECK_MSTATUS( attributeAffects(aPointO, aOutColor) );
CHECK_MSTATUS( attributeAffects(aPointW, aOutColor) );
CHECK_MSTATUS( attributeAffects(aToggleCamera, aOutColor) );
CHECK_MSTATUS( attributeAffects(aToggleObject, aOutColor) );
CHECK_MSTATUS( attributeAffects(aToggleWorld, aOutColor) );
return MS::kSuccess;
}
//
// DESCRIPTION:
MStatus VolumeNode::compute(const MPlug& plug, MDataBlock& block )
{
if ((plug != aOutColor) && (plug.parent() != aOutColor) &&
(plug != aOutTransparency) && (plug.parent() != aOutTransparency))
return MS::kUnknownParameter;
MFloatVector& InputColor = block.inputValue( aColor ).asFloatVector();
float Distance = block.inputValue( aInputValue ).asFloat();
MFloatVector& FarCamera = block.inputValue( aFarPointC ).asFloatVector();
MFloatVector& FarObject = block.inputValue( aFarPointO ).asFloatVector();
MFloatVector& FarWorld = block.inputValue( aFarPointW ).asFloatVector();
MFloatVector& PointCam = block.inputValue( aPointC ).asFloatVector();
MFloatVector& PointObj = block.inputValue( aPointO ).asFloatVector();
MFloatVector& PointWor = block.inputValue( aPointW ).asFloatVector();
bool Camera = block.inputValue( aToggleCamera ).asBool();
bool Object = block.inputValue( aToggleObject ).asBool();
bool World = block.inputValue( aToggleWorld ).asBool();
MFloatVector interval(0.0,0.0,0.0);
if (Camera) {
interval = FarCamera - PointCam;
}
if (Object) {
interval = FarObject - PointObj;
}
if (World) {
interval = FarWorld - PointWor;
}
double value = (interval[0]*interval[0]) +
(interval[1]*interval[1]) +
(interval[2]*interval[2]);
double dist = sqrt ( value );
MFloatVector resultColor(0.0,0.0,0.0);
if (dist <= Distance) {
resultColor[0] = InputColor[0];
resultColor[1] = InputColor[1];
resultColor[2] = InputColor[2];
}
// set ouput color attribute
MDataHandle outColorHandle = block.outputValue( aOutColor );
MFloatVector& outColor = outColorHandle.asFloatVector();
outColor = resultColor;
outColorHandle.setClean();
// set output transparency
MFloatVector transparency(resultColor[2],resultColor[2],resultColor[2]);
MDataHandle outTransHandle = block.outputValue( aOutTransparency );
MFloatVector& outTrans = outTransHandle.asFloatVector();
outTrans = transparency;
outTransHandle.setClean( );
MDataHandle outAlphaHandle = block.outputValue( aOutAlpha );
float& outAlpha = outAlphaHandle.asFloat();
outAlpha = resultColor[2];
outAlphaHandle.setClean( );
return MS::kSuccess;
}
//
// DESCRIPTION:
MStatus initializePlugin( MObject obj )
{
const MString UserClassify( "shader/volume" );
MFnPlugin plugin( obj, PLUGIN_COMPANY, "4.5", "Any");
CHECK_MSTATUS( plugin.registerNode( "volumeNode", VolumeNode::id,
VolumeNode::creator, VolumeNode::initialize,
MPxNode::kDependNode, &UserClassify ) );
return MS::kSuccess;
}
//
// DESCRIPTION:
MStatus uninitializePlugin( MObject obj )
{
MFnPlugin plugin( obj );
CHECK_MSTATUS( plugin.deregisterNode( VolumeNode::id ) );
return MS::kSuccess;
}
// =====================================================================
// Copyright 2018 Autodesk, Inc. All rights reserved.
//
// This computer source code and related instructions and comments are
// the unpublished confidential and proprietary information of Autodesk,
// Inc. and are protected under applicable copyright and trade secret
// law. They may not be disclosed to, copied or used by any third party
// without the prior written consent of Autodesk, Inc.
// =====================================================================