Question

I’m looking for a way to improve my particle system performance, since it is very costly in terms of FPS.
This is because I call:

glDrawElements(GL_TRIANGLE_STRIP, mNumberOfIndices,
          GL_UNSIGNED_SHORT, 0);

I call this method for every particle in my application (which could be between 1000 and 5000 particles). Note that when increasing to over 1000 particles my application starting to drop down in FPS. I’m using VBO:s, but the performance when calling this method is too costly.

Any ideas how I can make the particle system more efficient?

Edit: This is how my particle system draw things:

glBindTexture(GL_TEXTURE_2D, textureObject);
glBindBuffer(GL_ARRAY_BUFFER, vboVertexBuffer[0]);
glVertexPointer(3, GL_FLOAT, 0, 0);
glBindBuffer(GL_ARRAY_BUFFER, vboTextureBuffer[0]);
glTexCoordPointer(2, GL_FLOAT, 0, 0); 
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboIndexBuffer[0]);

Vector3f partPos;

for (int i = 0; i < m_numParticles; i++) {
    partPos = m_particleList[i].m_pos;          
    glTranslatef(partPos.x, partPos.y, partPos.z);
    glDrawElements(GL_TRIANGLE_STRIP, mNumberOfIndices, 
        GL_UNSIGNED_SHORT, 0);
    gl.glTranslatef(-partPos.x, -partPos.y, -partPos.z);
}

Answer 1

The way you describe it, it sounds like you have a own VBO for each particle. This is not how it should be done. Put all particles into a single VBO and draw them all at once using a single glDrawElements or glDrawArrays call. Or even better, if available: Use instancing.