...
float time : input, time of evaluation of the box.
Returns
Nothing.
getNumberOfUVGenerators
virtual byte getNumberOfUVGenerators( void );Returns the number of implemented custom UV generators.
Arguments
None.
Returns
Number of UV generators. Max 255.
getUVGeneratorName
virtual const char* getUVGeneratorName( byte index );Return a string with the name of the UV generator.
Arguments
byte index : input, index of the generator, max 255.
Returns
String with the generator name. If index > numberOfUVGenerators or index < 0, return NULL.
getUVForChannel
virtual byte getUVForChannel( CfVector& uvw, const Cpoint& point, const Cpoint& normal, dword iGenerator,
dword subVolIndex, const Cvector& parametricUVW );
Calculates the UV texture coordinates for the given point "point". When dealing with analytical surfaces, it's often more convenient to use "parametricUVW" as input data. "normal" is the normal at the intersection point.
Arguments
CfVector& uvw : output, calculated texture coordinates, values range from 0.0 to 1.0.
const Cpoint& point : input, intersection point.
const Cpoint& normal : input, normal at intersection point.
dword iGenerator : input, index of the chosen generator.
dword subVolIndex : input, index of the subvolume.
const Cvector& parametricUVW : input, natural parametric coordinates of the surface, calculated in intersect.
Returns
1 on success, 0 otherwise.
isOverlappingBoundingBox
virtual bool isOverlappingBoundingBox( const Cpoint *bboxPoints, dword subVolumeIndex, bool forceHalfTime );Helper function for the render engine. Tests whether the box given by "bboxPoints" and that of the subvolume indexed by "subVolumeIndex" overlap.
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#include <math.h>
#include "extensionmanager.h"
#include "geometryextension.h"
#include "maxwell.h"
#ifndef DEG2RAD
#define DEG2RAD(d) ((d) * 3.14159265358979323846 / 180.0)
#endif
class SphereRenderExtension : public CgeometryProceduralExtension
{
DECLARE_EXTENSION_METHODS( "SphereRenderExample", SphereRenderExtension, 1 )
Cmaxwell* pMaxwellLocal;
double radius;
public:
SphereRenderExtension()
{
getExtensionData()->createDouble( "Radius", 1.00, 0, 1000000 );
}
~SphereRenderExtension()
{
}
bool initializeForRendering ( Cmaxwell* pMaxwell )
{
pMaxwellLocal = pMaxwell;
getExtensionData()->getDouble( "Radius", radius );
return true;
}
//Helper function to spit messages to maxwell.
void printMessage( const char* text, const int code )
{
if( pMaxwellLocal != NULL )
{
char pMessage[ 1024 ];
sprintf ( pMessage, "[Extension %s] %s", getName(), text );
pMaxwellLocal->printMessage( pMessage, code );
}
}
dword getNumSubVolumes( void )
{
return 1;//We just have one region surrounding the whole sphere
};
bool intersect( Cmaxwell::Cobject* object, const Cpoint& origin, const Cvector& dir,
real time, const dword subVolumeIndex, Cvector* pNormal, Cvector* pLocalImpact,
CfVector &data, Cvector& parametricUVW, Cvector& tangentU, Cvector& tangentV )
{
real dist, a, b, disc, t0, t1, sqr;
dist = -1.0;
//Assume sphere centered in ( 0, 0, 0 ) in local coordinates
a = 2*( dir.x*origin.x + dir.y*origin.y + dir.z*origin.z );
b = origin.x*origin.x + origin.y*origin.y + origin.z*origin.z - radius*radius;
disc = a*a - 4*b;
if ( disc < 0.0 )
{
return false;
}
sqr = sqrt ( disc );
t0 = ( -a - sqr ) * 0.5;
t1 = ( -a + sqr ) * 0.5;
if ( t0 <= 0.0 )
{
if ( t1 > 0.0 )
{
dist = t1;
}
else
{
return false;
}
}
else
{
if ( t0 < t1 ) dist = t0;
else dist = t1;
}
Cvector p;
p.assign( origin + dir * dist );//Point of intersection in local coordinates
pLocalImpact->assign( p );
Cvector normal;
normal.assign( p );
pNormal->assign( normal );//No need to normalize. Done later on demand.
return true;
}
void getBoundingBox( Cvector& bmin, Cvector& bmax, float time )
{
bmin.assign( -radius, -radius, -radius );
bmax.assign( radius, radius, radius );
}
};
EXPORT_GEOMETRY_PROCEDURAL_EXTENSION( SphereRenderExtension ) |