Help building a ofVbo mesh

beginners
#1

Hi,

I am trying to build a simple ofVbo mesh, find my results in the attach image, I believe I am calculating the indices correctly, but looks like the indices are not matching the vertices positions

This is my code

  
mTotalVertices	= GRID_ROWS * GRID_COLUMS;  
mTotalTriangles	= ((GRID_ROWS - 1) * (GRID_COLUMS - 1)) * 2;  
mTotalIndices	= mTotalTriangles * 3;  
	  
mParticleSize	= 8.0f;  
	  
int spaceX		= GRID_WIDTH  / GRID_ROWS;  
int spaceY		= GRID_HEIGHT / GRID_COLUMS;  
  
mGridCenterX	= ((GRID_ROWS	- 1) * spaceX) / 2;  
mGridCenterY	= ((GRID_COLUMS - 1) * spaceY) / 2;  
	  
GLuint indices[mTotalIndices];  
	  
int ind = 0;  
	  
for ( int i = 0; i < GRID_ROWS; i++ ) {  
	for ( int j = 0; j < GRID_COLUMS; j++ ) {  
		// calc indices  
		int a, b, c, d, e, f;	  
		if ( (i + 1 < GRID_ROWS) && (j + 1 < GRID_COLUMS) ) {  
			a = (i + 0) * GRID_COLUMS + (j + 0);  
			b = (i + 0) * GRID_COLUMS + (j + 1);  
			c = (i + 1) * GRID_COLUMS + (j + 0);  
			  
			d = (i + 0) * GRID_COLUMS + (j + 1);  
			e = (i + 1) * GRID_COLUMS + (j + 1);  
			f = (i + 1) * GRID_COLUMS + (j + 0);  
				  
			indices[ind]   = a;  
			indices[ind+1] = b;  
			indices[ind+2] = c;  
			  
			indices[ind+3] = d;  
			indices[ind+4] = e;  
			indices[ind+5] = f;  
				  
			ind += 6;  
		}  
			  
		// calc vertices positions  
		int index	= i + j * GRID_ROWS;  
		int x		= i * spaceX;  
		int y		= j * spaceY;  
		int z		= 0;  
			  
		vertices[index].set( x, y, z );  
	}  
}  
	  
// Set shape indices  
shape.setIndexData( indices, mTotalIndices, GL_STATIC_DRAW );  
shape.setVertexData( vertices, mTotalVertices, GL_DYNAMIC_DRAW );

And this is how I draw

  
shape.bind();  
shape.updateVertexData( vertices, mTotalVertices );  
shape.draw( GL_TRIANGLES, 0, mTotalVertices );  
shape.unbind();

This are my ofVbo indices,
**total vertices: 16
total triangles: 18
total indices: 54
indices: 0
indices: 1
indices: 4
indices: 1
indices: 5
indices: 4
indices: 1
indices: 2
indices: 5
indices: 2
indices: 6
indices: 5
indices: 2
indices: 3
indices: 6
indices: 3
…
**
Thanks in advance

  • rS