customImagePlane.py

#-
# ==========================================================================
# Copyright (C) 1995 - 2006 Autodesk, Inc. and/or its licensors.  All 
# rights reserved.
#
# The coded instructions, statements, computer programs, and/or related 
# material (collectively the "Data") in these files contain unpublished 
# information proprietary to Autodesk, Inc. ("Autodesk") and/or its 
# licensors, which is protected by U.S. and Canadian federal copyright 
# law and by international treaties.
#
# The Data is provided for use exclusively by You. You have the right 
# to use, modify, and incorporate this Data into other products for 
# purposes authorized by the Autodesk software license agreement, 
# without fee.
#
# The copyright notices in the Software and this entire statement, 
# including the above license grant, this restriction and the 
# following disclaimer, must be included in all copies of the 
# Software, in whole or in part, and all derivative works of 
# the Software, unless such copies or derivative works are solely 
# in the form of machine-executable object code generated by a 
# source language processor.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND. 
# AUTODESK DOES NOT MAKE AND HEREBY DISCLAIMS ANY EXPRESS OR IMPLIED 
# WARRANTIES INCLUDING, BUT NOT LIMITED TO, THE WARRANTIES OF 
# NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR 
# PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE, OR 
# TRADE PRACTICE. IN NO EVENT WILL AUTODESK AND/OR ITS LICENSORS 
# BE LIABLE FOR ANY LOST REVENUES, DATA, OR PROFITS, OR SPECIAL, 
# DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES, EVEN IF AUTODESK 
# AND/OR ITS LICENSORS HAS BEEN ADVISED OF THE POSSIBILITY 
# OR PROBABILITY OF SUCH DAMAGES.
#
# ==========================================================================
#+

#
# Description: 
#   Demonstrates how to create your own custom image plane based on
#   Maya's internal image plane classes. This allows API users to
#   override the default Maya image plane behavior. This class works
#   like typical API nodes in that it can have a compute method and
#   can contain static attributes added by the API user.  This
#   example class overrides the default image plane behavior and
#   allows users to add transparency to an image plane using the
#   transparency attribute on the node. Note, this code also 
#   illustrates how to use MImage to control the floating point
#   depth buffer.  When useDepthMap is set to true, depth is added
#   is added to the image such that half of the iamge is at the near 
#   clip plane and the remaining half is at the far clip plane. 
#
#   Note, once the image plane node has been created it you must
#   attached it to the camera shape that is displaying the node.
#   Image planes are attached to cameras via the imagePlane message
#   attribute on the camera shape.  To attach this example image
#   plane you should connect the image plane's message attribute to
#   the cameraShapes imagePlane attribute.  Note, the imagePlane
#   attribute is a multi attribute and can hold references to
#   multiple image planes.
#
# Usage:
#
#       Run the script:
#
#       import maya
#       maya.cmds.loadPlugin("customImagePlane.py")
#       imageP = maya.cmds.createNode("spCustomImagePlane")
#       maya.cmds.connectAttr( imageP + ".message", "perspShape.imagePlane[0]", force = True )
#
#       Then assign an image to the customImagePlane node
#

import maya.OpenMaya as OpenMaya
import maya.OpenMayaMPx as OpenMayaMPx
import sys

kPluginNodeTypeName = "spCustomImagePlane"
kPluginNodeId = OpenMaya.MTypeId(0x87016)

# Node definition
class customImagePlane(OpenMayaMPx.MPxImagePlane):
        # class variables
        aTransparency = OpenMaya.MObject()
        
        # internal variables
        fTransparency = 0.0
                        
        def __init__(self):
                OpenMayaMPx.MPxImagePlane.__init__(self)
                
        def getInternalValueInContext( self, plug, handle, context ):
                if plug == self.aTransparency:
                        handle.setDouble( self.fTransparency )
                        return True
                
                return OpenMayaMPx.MPxImagePlane.getInternalValueInContext( self, plug, handle, context )
        
        def setInternalValueInContext( self, plug, handle, context ):
                if plug == self.aTransparency:
                        self.fTransparency = handle.asDouble()
                        self.setImageDirty()
                        return True
                
                return OpenMayaMPx.MPxImagePlane.setInternalValueInContext( self, plug, handle, context )       
                
        def loadImageMap(self, fileName, frame, image):
                try:    
                        image.readFromFile(fileName)
                        
                        # get the width and height of the image an MScriptUtil is needed
                        # to pass in a pointer to the MImage::getSize() method
                        scriptUtil = OpenMaya.MScriptUtil()
                        widthPtr = scriptUtil.asUintPtr()
                        heightPtr = scriptUtil.asUintPtr()
                        scriptUtil.setUint( widthPtr, 0 )
                        scriptUtil.setUint( heightPtr, 0 )
                        image.getSize( widthPtr, heightPtr )
                        
                        width = scriptUtil.getUint(widthPtr)
                        height = scriptUtil.getUint(heightPtr)          
                        size = width * height
                        
                        # Implement transparency
                        charPixelPtr = image.pixels()
                        for i in range( 0, size, 4 ):
                                alphaIndex = (i*4)+3
                                alpha = OpenMayaScript.getCharArrayItem(charPixelPtr,alphaIndex)
                                OpenMayaScript.setCharArray( alpha * (1.0 - self.fTransparency), alphaIndex )
                        
                        # Implement use depth map
                        thisNode = self.thisMObject()
                        fnThisNode = OpenMaya.MFnDependencyNode(thisNode)
                        useDepthMap = fnThisNode.attribute("useDepthMap")
                        depthMap = OpenMaya.MPlug( thisNode, useDepthMap )
                        value = depthMap.asBool()
                        
                        if value:                               
                                buffer = []                     
                                c = 0
                                for i in range( 0, height ):
                                        for j in range( 0, width ):
                                                if i > height/2.0:
                                                        buffer.insert(c, -1.0)
                                                else:
                                                        buffer.insert(c, 0.0)
                                                c+=1
                                                
                                depthMapArray = OpenMaya.MScriptUtil()
                                depthMapArray.createFromList( buffer )
                                depthMapArrayFloatPtr = depthMapArray.asFloatPtr()
                                image.setDepthMap( depthMapArrayFloatPtr, width, height )
                                
                except:
                        pass
                        
# creator
def nodeCreator():
        return OpenMayaMPx.asMPxPtr( customImagePlane() )
        
# initializer
def nodeInitializer():
        nAttr = OpenMaya.MFnNumericAttribute()

        # Setup the input attributes
        customImagePlane.aTransparency = nAttr.create("transparency", "tp", OpenMaya.MFnNumericData.kDouble, 0.0)
        nAttr.setStorable(True)
        nAttr.setInternal(True)
        nAttr.setMin(0.0)
        nAttr.setMax(1.0)
        nAttr.setKeyable(True)
        
        customImagePlane.addAttribute(customImagePlane.aTransparency)
        
# initialize the script plug-in
def initializePlugin(mobject):
        mplugin = OpenMayaMPx.MFnPlugin(mobject, "Autodesk", "1.0", "Any")
        try:
                mplugin.registerNode( kPluginNodeTypeName, kPluginNodeId, nodeCreator, nodeInitializer, OpenMayaMPx.MPxNode.kImagePlaneNode )
        except:
                sys.stderr.write( "Failed to register node: %s" % kPluginNodeTypeName )
                raise


# uninitialize the script plug-in
def uninitializePlugin(mobject):
        mplugin = OpenMayaMPx.MFnPlugin(mobject)
        try:
                mplugin.deregisterNode( kPluginNodeId )
        except:
                sys.stderr.write( "Failed to register node: %s" % kPluginNodeTypeName )
                raise