geomShader/geomShader.cpp

//
// DESCRIPTION:
//

#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:
class GeomNode : public MPxNode
{
    public:
                     GeomNode();
             ~GeomNode() override;

   MStatus   compute( const MPlug&, MDataBlock& ) override;
    SchedulingType schedulingType() const override { return SchedulingType::kParallel; }

   static  void *    creator();
   static  MStatus   initialize();

    //  Id tag for use with binary file format
   static  MTypeId   id;

    private:

    // Input attributes
    static MObject aPoint;
    static MObject aScale;
    static MObject aOffset;

    // Output attributes
    static MObject aOutColor;
};

// static data
MTypeId GeomNode::id( 0x81004 );

// Attributes
MObject  GeomNode::aPoint;
MObject  GeomNode::aScale;
MObject  GeomNode::aOffset;
MObject  GeomNode::aOutColor;

#define MAKE_INPUT(attr)                                \
  CHECK_MSTATUS ( attr.setKeyable(true) );              \
  CHECK_MSTATUS ( attr.setStorable(true) );             \
  CHECK_MSTATUS ( attr.setReadable(true) );             \
  CHECK_MSTATUS ( attr.setWritable(true) );

#define MAKE_OUTPUT(attr)                               \
  CHECK_MSTATUS (attr.setKeyable(false) );              \
  CHECK_MSTATUS ( attr.setStorable(false));             \
  CHECK_MSTATUS ( attr.setReadable(true) );             \
  CHECK_MSTATUS ( attr.setWritable(false));

// DESCRIPTION:
//
GeomNode::GeomNode()
{
}

// DESCRIPTION:
//
GeomNode::~GeomNode()
{
}

// DESCRIPTION:
//
void* GeomNode::creator()
{
    return new GeomNode();
}

// DESCRIPTION:
//
MStatus GeomNode::initialize()
{
    MFnNumericAttribute nAttr; 

    // Input attributes

    aPoint = nAttr.createPoint( "pointObj", "p" );
    CHECK_MSTATUS ( nAttr.setStorable(false) );
    CHECK_MSTATUS ( nAttr.setHidden(true) );

    aScale = nAttr.createPoint( "scale", "s" );
    MAKE_INPUT(nAttr);
    CHECK_MSTATUS ( nAttr.setDefault(1.0f, 1.0f, 1.0f) );

    aOffset = nAttr.createPoint( "offset", "o" );
    MAKE_INPUT(nAttr);

    // Output attributes
    aOutColor  = nAttr.createColor( "outColor", "oc" );
    MAKE_OUTPUT(nAttr);

    // Add attributes to the node database.
    CHECK_MSTATUS ( addAttribute(aPoint) );
    CHECK_MSTATUS ( addAttribute(aScale) );
    CHECK_MSTATUS ( addAttribute(aOffset) );

    CHECK_MSTATUS ( addAttribute(aOutColor) );

    // All input affect the output color
    CHECK_MSTATUS ( attributeAffects (aPoint, aOutColor) );
    CHECK_MSTATUS ( attributeAffects (aScale, aOutColor) );
    CHECK_MSTATUS ( attributeAffects (aOffset,aOutColor) );

    return MS::kSuccess;
}

// DESCRIPTION:
//
MStatus GeomNode::compute(
const MPlug&      plug,
      MDataBlock& block ) 
{
    // outColor or individial R, G, B channel
    if((plug != aOutColor) && (plug.parent() != aOutColor))
        return MS::kUnknownParameter;

    MFloatVector resultColor;

    MFloatVector & point  = block.inputValue( aPoint ).asFloatVector();
    MFloatVector & scale  = block.inputValue( aScale ).asFloatVector();
    MFloatVector & offset = block.inputValue( aOffset ).asFloatVector();

    // Scale + Offset original geometry position
    resultColor.x = point.x * scale.x + offset.x;
    resultColor.y = point.y * scale.y + offset.y;
    resultColor.z = point.z * scale.z + offset.z;

    // set ouput color attribute
    MDataHandle outColorHandle = block.outputValue( aOutColor );
    MFloatVector& outColor = outColorHandle.asFloatVector();
    outColor = resultColor;
    outColorHandle.setClean();

    return MS::kSuccess;
}

//
// DESCRIPTION:
MStatus initializePlugin( MObject obj )
{
   const MString UserClassify( "utility/general" );

   MFnPlugin plugin( obj, PLUGIN_COMPANY, "4.5", "Any");
   CHECK_MSTATUS ( plugin.registerNode( "geomNode", GeomNode::id, 
                         GeomNode::creator, GeomNode::initialize,
                         MPxNode::kDependNode, &UserClassify ) );

   return MS::kSuccess;
}

//
// DESCRIPTION:
MStatus uninitializePlugin( MObject obj )
{
   MFnPlugin plugin( obj );
   CHECK_MSTATUS ( plugin.deregisterNode( GeomNode::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.
// =====================================================================