Hey folks,
I’m new to openGL and absolutely love it.
Problem:
I have multiple interleaved VBOs. The geometry itself is rendering properly. However, it appears that in some cases that the geometry from one VBO gets combined with the geometry from another VBO.
I’m rendering planets. Each planet contains 4 VBOs based on quality: low, med, high, best. These are selectively rendered based on camera distance from the planet surface.
Most planets render properly. In some situations a planet may render the geometry for itself as well as the geometry of another planet over top of itself.
Image attached.
Details:
Java / LWJGL on Win 7 x64
No shaders
Seems to be vedor specific:
Radeon HD 68xx - problem appears
GeForce 8600GT - no problem
GL_VENDOR: ATI Technologies Inc.
GL_VERSION: 4.2.11318 Compatibility Profile Context
GL_RENDERER: AMD Radeon HD 6800 Series
Does my approach below look correct?
private void prerender()
{
if ( !prerendered )
{
prerendered = true;
validateVerticies();
if ( verticies.length > 0 )
{
/*
* Setup Buffers
*/
// Generate buffer ids
buffers = BufferUtils.createIntBuffer(2);
GL15.glGenBuffers(buffers);
/*
* Setup VBO
*/
int floatCnt = verticies[0].getOutput().length;
vboBuffer = BufferUtils.createFloatBuffer(verticies.length*floatCnt);
for ( int i=0; i<verticies.length; ++i)
vboBuffer.put( verticies[i].getOutput() );
vboBuffer.flip();
// Bind and Upload
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, buffers.get(0));
GL15.glBufferData(GL15.GL_ARRAY_BUFFER, vboBuffer, GL15.GL_STATIC_DRAW);
// Pointer Data
// note: glVertexPointer should be at the end
GL11.glTexCoordPointer(2, GL11.GL_FLOAT, stride, offsetTexture);
GL11.glNormalPointer(GL11.GL_FLOAT, stride, offsetNormal);
GL11.glColorPointer(4, GL11.GL_FLOAT, stride, offsetColor);
GL11.glVertexPointer(3, GL11.GL_FLOAT, stride, offsetVertex);
/*
* Setup IBO
*/
int size = verticies.length*stride;
iboBuffer = BufferUtils.createIntBuffer(size);
for ( int i=0; i<size; ++i)
iboBuffer.put(i);
iboBuffer.flip();
// Bind and Upload
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, buffers.get(1));
GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, iboBuffer, GL15.GL_STATIC_DRAW);
checkError();
// Log
log("+ VBO:" + name + ", " + buffers.get(0) + ", " + buffers.get(1) );
}
}
}
/*
* Interleaved Data Format
* 3 vertex, 3 normal, 4 color, 2 texture, 4 padding
*
* Example Data (floats):
* {vX, vY, vZ, nX, nY, nZ, cX, cY, cZ, cA, tX, tY, 0f, 0f, 0f, 0f}
*
* floats are 4 bytes each
*
*/
private int floatBytes = 4;
private int stride = (3 + 3 + 4 + 2 + 4) * floatBytes; // should total 64;
private int offsetVertex = 0;
private int offsetNormal = (3) * floatBytes;
private int offsetColor = (3+3) * floatBytes;
private int offsetTexture = (3+3+4) * floatBytes;
/*
* Render VBO data
*
*/
public void render()
{
if ( verticies.length > 0 )
{
prerender();
// Bind the vertex buffer and the index buffer
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, buffers.get(0));
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, buffers.get(1));
// Enable State
GL11.glEnableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
GL11.glEnableClientState(GL11.GL_NORMAL_ARRAY);
GL11.glEnableClientState(GL11.GL_COLOR_ARRAY);
GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
// Pointer Data
GL11.glTexCoordPointer(2, GL11.GL_FLOAT, stride, offsetTexture);
GL11.glNormalPointer(GL11.GL_FLOAT, stride, offsetNormal);
GL11.glColorPointer(4, GL11.GL_FLOAT, stride, offsetColor);
GL11.glVertexPointer(3, GL11.GL_FLOAT, stride, offsetVertex);
/*
* Debug: Check the current binding
*/
IntBuffer response = BufferUtils.createIntBuffer(16);
GL11.glGetInteger(GL15.GL_ARRAY_BUFFER_BINDING, response);
int arrayBinding = response.get(0);
GL11.glGetInteger(GL15.GL_COLOR_ARRAY_BUFFER_BINDING, response);
int colorBinding = response.get(0);
GL11.glGetInteger(GL15.GL_VERTEX_ARRAY_BUFFER_BINDING, response);
int vertexBinding = response.get(0);
if ( arrayBinding != buffers.get(0) || colorBinding != buffers.get(0) || vertexBinding != buffers.get(0) )
{
log("BINDING ERROR!");
}
// Draw
GL11.glDrawElements(type, verticies.length*stride, GL11.GL_UNSIGNED_INT, 0);
// Log
log("> VBO:" + name + ", " + buffers.get(0) + ", " + buffers.get(1) + ", verts: " + verticies.length);
// Disable State
GL11.glDisableClientState(GL11.GL_VERTEX_ARRAY);
GL11.glDisableClientState(GL11.GL_NORMAL_ARRAY);
GL11.glDisableClientState(GL11.GL_COLOR_ARRAY);
GL11.glDisableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
// Unbind
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);
}
}
Any suggestions would be appreciated.
