intersectOnNurbsSurfaceCmd/intersectOnNurbsSurfaceCmd.cpp

intersectOnNurbsSurfaceCmd/intersectOnNurbsSurfaceCmd.cpp
//-
// ==========================================================================
// Copyright 1995,2006,2008 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
// ==========================================================================
//+
// Description:
// A command which exercises the various NURBS intersect methods
// available in the API. The command expects all data it needs to work
// with to be on the selection list.
//
// Usage:
// Before calling this command, the selection list needs to have
// the following nodes selected in order:
//
// o A NURBS surface, such as nurbsPlaneShape1. The surface may
// be transformed in the DAG, if desired.
// o The transform node of a locator. The user should place the
// locator at the point in 3-space for which they want to find
// the intersect on the NURBS surface.
//
// When invoked with the above items in order on the selection list,
// the command proceeds to calculate the intersect on the NURBS
// surface, moving "locator2" to the computed intersect to allow
// the user to visually see what intersect was calculated.
//
// Example:
// 1. Compile and load this plug-in into Maya.
// 2. Create a NURBS surface, such as a NURBS plane. Move some CVs
// to obtain a wavy surface.
// 3. Create two locators, locator1 and locator2, (both should be
// children of the world because the plug-in translates locator2
// to the calculated closest intersect value for display purposes).
// 4. Position the first locator somewhere in 3D space over the
// surface.
// 5. Position the second locator so that the line that passes through
// both locators intersects the NURBS surface. Note that the second
// locator will be automatically moved to the closest intersect on the
// surface by the command.
// 5. Select the two objects:
// MEL> select nurbsPlaneShape1 locator1 locator2;
// 6. Invoke this command:
// MEL> intersectOnNurbsSurface;
// 7. You should see locator2 move to the point on the NURBS
// surface which is closest to locator1.
// 8. Move locator1 and locator2 to different positions and invoke this
// command again. You should see locator2 move to the correct
// closest intersect each time.
// 9. Try rotating, scaling and translating the NURBS surface's
// transform node and you should see the intersect being
// correctly computed.
//
#include <math.h>
// MAYA HEADERS
#include <maya/MIOStream.h>
#include <maya/MArgList.h>
#include <maya/MPxCommand.h>
#include <maya/MGlobal.h>
#include <maya/MSelectionList.h>
#include <maya/MPoint.h>
#include <maya/MNurbsIntersector.h>
#include <maya/MDagPath.h>
#include <maya/MMatrix.h>
#include <maya/MFnDagNode.h>
#include <maya/MFnTransform.h>
#include <maya/MVector.h>
#include <maya/MFnPlugin.h>
#include <maya/MFnNurbsSurface.h>
#include "intersectOnNurbsSurfaceCmd.h"
// CONSTRUCTOR:
intersectOnNurbsSurfaceCmd::intersectOnNurbsSurfaceCmd()
{
}
// DESTRUCTOR:
intersectOnNurbsSurfaceCmd::~intersectOnNurbsSurfaceCmd()
{
}
// FOR CREATING AN INSTANCE OF THIS COMMAND:
void* intersectOnNurbsSurfaceCmd::creator()
{
return new intersectOnNurbsSurfaceCmd;
}
// MAKE THIS COMMAND NOT UNDOABLE:
bool intersectOnNurbsSurfaceCmd::isUndoable() const
{
return false;
}
MStatus intersectOnNurbsSurfaceCmd::doIt(const MArgList& args)
// Description:
// See the command usage at the top of this file for details
// on how to use this command.
//
{
bool debug = false;
bool treeBased = true;
if(debug) cout << "intersectOnNurbsSurfaceCmd::doIt\n";
if(!stat) {
if(debug) cout << "getActiveSelectionList FAILED\n";
return( stat );
}
MDagPath path;
MObject nurbsObject;
stat = list.getDependNode(0,nurbsObject);
if(!stat)
if(debug) cout << "getDependNode FAILED\n";
MFnDagNode nodeFn(nurbsObject);
// don't use the transform, use the shape
if(nodeFn.childCount() > 0) {
MObject child = nodeFn.child(0);
nodeFn.setObject(child);
}
list.getDagPath(0,path);
if(debug) cout << "Working with: " << path.partialPathName() << endl;
if(debug) cout << mat << endl;
MObject loc1Object;
stat = list.getDependNode(1, loc1Object); // use the transform, not the shape
if(!stat) {
if(debug) cout << "FAILED grabbing locator1\n";
return( stat );
}
MObject loc2Object;
stat = list.getDependNode(2, loc2Object); // use the transform, not the shape
if(!stat) {
if(debug) cout << "FAILED grabbing locator2\n";
return( stat );
}
MFnTransform loc1Fn(loc1Object);
MVector t = loc1Fn.getTranslation(MSpace::kObject);
MFnTransform loc2Fn(loc2Object);
MVector t2 = loc2Fn.getTranslation(MSpace::kObject);
MVector ray = t2 - t;
MPoint pt(t[0], t[1], t[2]);
if(debug) cout << "test point: " << pt << endl;
if(debug) cout << "transformed:" << pt * mat << endl;
MPoint resultPoint;
double u=0, v=0;
if ( treeBased ) {
// Use the tree-based NURBS intersect algorithm.
// The idea is to call create() once, then reuse for later calls
// to getIntersect(). In our example, we'll just do one
// getIntersect() call.
//
if(debug) cout << "tree-based NURBS intersect (MNurbsIntersector)\n";
MNurbsIntersector nurbIntersect;
stat = nurbIntersect.create(nurbsObject, mat);
if(!stat) {
if(debug) cout << "MNurbsIntersector::create FAILED\n";
return( stat );
}
stat = nurbIntersect.getIntersect(pt, ray, u, v, resultPoint, kMFnNurbsEpsilon);
if(!stat) {
if(debug) cout << "MNurbsIntersector::getIntersect FAILED!\n";
return( stat );
}
} else {
// Use the non-tree NURBS intersect algorithm from MFnNurbsSurface.
//
MFnNurbsSurface ns( nurbsObject );
pt *= mat; // Need to transform into object space ourselves
bool result = ns.intersect(pt, ray, u, v, resultPoint, kMFnNurbsEpsilon, MSpace::kObject, false, NULL, false, NULL, &stat );
if(!result || !stat) {
if(debug) cout << "MFnNurbsSurface::intersect FAILED!\n";
if(stat) {
}
return( stat );
}
}
// As a check, grab the world space point that corresponds to the
// UVs returned from getIntersect.
//
if(debug) cout << "result UV: " << u << ", " << v << endl;
MString cmd = "pointOnSurface -u ";
cmd += u;
cmd += " -v ";
cmd += v;
cmd += " ";
cmd += path.partialPathName();
if(debug) cout << "check results: result UV corresponds to world point: " << arr << endl;
MPoint worldResultPoint = resultPoint * path.inclusiveMatrix();
if(debug) cout << "local space result point: " << resultPoint << endl;
if(debug) cout << "world space result point: " << worldResultPoint << endl;
if ( fabs( arr[0] - worldResultPoint.x ) > 0.0001
|| fabs( arr[1] - worldResultPoint.y ) > 0.0001
|| fabs( arr[2] - worldResultPoint.z ) > 0.0001 ) {
cout << "check results: pointOnSurface does not match world point: " << arr << endl;
return( MS::kFailure );
}
// Move the second locator to the returned world-space point
// This should always be on the nurbs surface.
// Note: we are assuming with both locators that they are children of
// the world.
//
stat = loc2Fn.setTranslation(worldResultPoint, MSpace::kTransform);
return stat;
}
// UNDO THE COMMAND
MStatus intersectOnNurbsSurfaceCmd::undoIt()
{
MStatus status;
// undo not implemented
return status;
}
//
// The following routines are used to register/unregister
// the command we are creating within Maya
//
MStatus initializePlugin( MObject obj )
{
MStatus status;
MFnPlugin plugin( obj, PLUGIN_COMPANY, "8.5", "Any");
status = plugin.registerCommand( "intersectOnNurbsSurface",
intersectOnNurbsSurfaceCmd::creator );
if (!status) {
status.perror("registerCommand");
return status;
}
return status;
}
MStatus uninitializePlugin( MObject obj)
{
MStatus status;
MFnPlugin plugin( obj );
status = plugin.deregisterCommand( "intersectOnNurbsSurface" );
if (!status) {
status.perror("deregisterCommand");
return status;
}
return status;
}