MarSTDv2004: CIsosurface Class Reference

MarSTDv2004

CIsosurface Class Reference

Collaboration diagram for CIsosurface:

Detailed Description

Use this class to visualize iso surfaces. Support has been added to calculate energy values for metaballs. The calculation of the generated triangles is done using the marching cubes algoritm. This algoritms is patented, so be carefull using it in a commercial product!

// Example:

void render() {

        load_camera();
        
        // Create a medium sized iso surface.
        static CIsosurface iso;
        iso.setSize(10, 10, 10);

        // Create a metaball.
        CIsosurfaceMetaball ball;
        ball.p[0] = sin(time);
        ball.p[1] = 0.0;
        ball.p[2] = cos(time);
        ball.a = 1.0;

        iso.calculate(&ball, 1);                // Calculate energy values using metaballs.
        iso.calculateNormals();         // Calculate normals.

        // Output triangles.    
        
        CIsosurfaceVertex v[300];
        glVertexPointer(GL_FLOAT, 3, v, sizeof(CIsosurfaceVertex));
        glEnableClientState(GL_NORMAL_ARRAY);
        glNormalPointer(GL_FLOAT, v, sizeof(CIsosurfaceVertex));
        glEnableClientState(GL_VERTEX_ARRAY);   

        glBegin(GL_TRIANGLES); {        
                iso.output(100, v, render_triangle);
        } glEnd();
        
}

void render_triangle(int triangles, CIsosurfaceVertex* v) {
        glDrawArrays(0, triangles*3);
}

Definition at line 111 of file CIsosurface.h.


Public Member Functions
void	setSize (int sx, int sy, int sz)
void	calculate (CIsosurfaceMetaball *ball, int balls)
void	calculateNormals ()
void	output (void(triangle)(CIsosurfaceVertex v))
void	output (int triangles, CIsosurfaceVertex v, void(triangle)(int num, CIsosurfaceVertex *v))
void	output (CMesh &mesh)
Public Attributes
CIsosurfaceValue ***	v
	Energy values.
CIsosurfaceCube ***	cube
	Cube for marching cubes algo.
int	sx
int	sy
int	sz
	Size of the grid.
float	treshold
	Isosurface border. If energy(x, y, z) >= treshold, (x, y, z) is solid.

Member Function Documentation

void CIsosurface::setSize	(	int	sx,
		int	sy,
		int	sz
	)

Sets the size of the grid. Passing (0, 0, 0) will free memory.

Parameters:

	sx	Resolution in x direction.
	sy	Resolution in y direction.
	sz	Resolution in z direction.

void CIsosurface::calculate	(	CIsosurfaceMetaball *	ball,
		int	balls
	)

Calculates energy values for a given number of mataballs. Note that you don't have to use this function to generate energy values. You can use all kinds of custom functions to do this.

Parameters:

	ball	Pointer to first ball in array.
	balls	The size of the ball array.

void CIsosurface::calculateNormals

(

)

Call this just before output() to have valid normal values if you need them.

void CIsosurface::output

(

void(*)(CIsosurfaceVertex *v)

triangle

)

Spawns triangles. The callback function will be called for every triangle with three metavert_t structures.

Parameters:

triangle

Callback function that will be called for every generated triangle.

void CIsosurface::output	(	int	triangles,
		CIsosurfaceVertex *	v,
		void()(int num, CIsosurfaceVertex v)	triangle
	)

Spawns multiple triangles at once. Triangles is the maximum number of triangles to spawn at once. v must be an array of triangles*3 metavert_t structures. The callback function will be called with the number of triangles to render and a pointer to v. Triangles are stored 123.123.123.

Parameters:

	triangles	The maximum number of triangles to output at once.
	v	An array of vertices large enough to store triangles*3 vertices.
	triangle	Callback function that will be called for multiple generated triangles.