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The most important part of the extension functionality resides in loadMesh, which must be implemented. The rest are optional functions. getBoundingBox, if implemented, returns the maximum and minimum points of the geometry's bounding box, in local coordinates of the object. This function is called at the voxelization stage, just before starting to render.
One of the other three functions getProxyDisplay* should be implemented if the extension writer wants to draw an approximate proxy of the object in the Studio viewport. For example, the MaxwellGrass extension uses getProxyDisplayLines to draw some lines representing grass strands.
The class extension constructor is used mainly to create the extension parameters (look at the example below) and, possibly, allocate data structures needed throughout the life of the extension. These data structures must be freed in the class destructor. initializeForRendering is called just before rendering starts, and the incoming pMaxwell (always check != NULL ) is useful for accessing the scene while executing loadMesh.
loadMesh
virtual bool loadMesh( Cmaxwell::Cobject& meshToLoad ) = 0;Main function of the extension. It is where the actual work of filling a geometric object is done.
Arguments
Cmaxwell::Cobject& meshToLoad : input/output, reference to the object being created.
Returns
true on success, otherwise false;
getBoundingBox
virtual bool getBoundingBox( Cpoint& min, Cpoint& max );Returns the bounding box of the newly created object, in local coordinates of the object.
Arguments
Cpoint& min : output, reference to the lower corner of the bounding box.
Cpoint& max : output, reference to the upper corner of the bounding box.
Returns
true on success, otherwise false;
getProxyDisplayPoints
virtual bool getProxyDisplayPoints( const dword& percent, const dword& maxPoints, dword& nPoints, float*& points );Allocates and fills the "points" array with the coordinates of points to be drawn in the Studio viewport. Also sets "nPoints" to the actual number of points filled. "points" array is of size 3*nPoints floats.
Arguments
const dword& percent : input, goes from 0 to 100, indicating the degree of desired precision to draw the proxy.
const dword& maxPoints : input, the maximum number of points allowed.
dword& nPoints : output, the actual number of points allocated. Must be <= maxPoints.
float*& points : output, array with the points, x0y0z0x1y1z1x2y2z2....
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#include <math.h> #include "extensionmanager.h" #include "geometryextension.h" #include "maxwell.h" class CubeExampleExtension : public CgeometryLoaderExtension { DECLARE_EXTENSION_METHODS( "CubeExample", CubeExampleExtension, 1 ) Cmaxwell* pMaxwellLocal; //Handy to access the scene. If you want to use it, fill it in initializeForRendering public: CubeExampleExtension() { getExtensionData()->createDouble( "Cube size", 1.0, 0, 1000 );//Create parameter with Default value } ~CubeExampleExtension() { } bool initializeForRendering ( Cmaxwell* pMaxwell ) { pMaxwellLocal = pMaxwell; return true; } bool loadMesh( Cmaxwell::Cobject &cube ) { //Get the extension parameter getExtensionData()->getDouble( "Cube size", cubeSize ); //Create the mesh cube.initializeMesh( 8, 6, 12, 1 ); //Add the vertices Cpoint point; point.assign( 0.0, 0.0, 0.0 ); cube.setVertex ( 0, 0, point ); point.assign( 0.0, 0.0, cubeSize ); cube.setVertex ( 1, 0, point ); point.assign( cubeSize, 0.0, cubeSize ); cube.setVertex ( 2, 0, point ); point.assign( cubeSize, 0.0, 0.0 ); cube.setVertex ( 3, 0, point ); point.assign( 0.0, cubeSize, 0.0 ); cube.setVertex ( 4, 0, point ); point.assign( 0.0, cubeSize, cubeSize ); cube.setVertex ( 5, 0, point ); point.assign( cubeSize, cubeSize, cubeSize ); cube.setVertex ( 6, 0, point ); point.assign( cubeSize, cubeSize, 0.0 ); cube.setVertex ( 7, 0, point ); //Set some normals Cvector normal; normal.assign( 1.0, 0.0, 0.0 ); cube.setNormal( 0, 0, normal ); normal.assign( -1.0, 0.0, 0.0 ); cube.setNormal( 1, 0, normal ); normal.assign( 0.0, 1.0, 0.0 ); cube.setNormal( 2, 0, normal ); normal.assign( 0.0, -1.0, 0.0 ); cube.setNormal( 3, 0, normal ); normal.assign( 0.0, 0.0, 1.0 ); cube.setNormal( 4, 0, normal ); normal.assign( 0.0, 0.0, -1.0 ); cube.setNormal( 5, 0, normal ); //Add triangles cube.setTriangle ( 0, 0, 2, 1, 3, 3, 3 ); cube.setTriangle ( 1, 0, 3, 2, 3, 3, 3 ); cube.setTriangle ( 2, 4, 5, 6, 2, 2, 2 ); cube.setTriangle ( 3, 4, 6, 7, 2, 2, 2 ); cube.setTriangle ( 4, 2, 3, 7, 0, 0, 0 ); cube.setTriangle ( 5, 2, 7, 6, 0, 0, 0 ); cube.setTriangle ( 6, 0, 1, 5, 1, 1, 1 ); cube.setTriangle ( 7, 0, 5, 4, 1, 1, 1 ); cube.setTriangle ( 8, 1, 2, 6, 4, 4, 4 ); cube.setTriangle ( 9, 1, 6, 5, 4, 4, 4 ); cube.setTriangle ( 10, 0, 4, 7, 5, 5, 5 ); cube.setTriangle ( 11, 0, 7, 3, 5, 5, 5 ); //Generate some uvs dword cchanIdx = 0; dword daChan; cube.addChannelUVW( daChan, cchanIdx ); Cbase projBase; projBase.origin.assign( 0.5, 0.5, 0.5 ); projBase.xAxis.assign( 1.0, 0.0, 0.0 ); projBase.yAxis.assign( 0.0, 1.0, 0.0 ); projBase.zAxis.assign( 0.0, 0.0, 1.0 ); Cvector scale; scale.assign( 0.5, 0.5, 1.0 ); byte sux = cube.generateCubicUVW( cchanIdx, projBase ); return true; } bool getBoundingBox( Cvector &bmin, Cvector& bmax) { bmin.assign( -cubeSize, -cubeSize, -cubeSize ); bmax.assign( cubeSize, cubeSize, cubeSize ); return true; } }; EXPORT_GEOMETRY_LOADER_EXTENSION( CubeExampleExtension ) |