Hi All, I'm working with NeHe's particle engine tutorial. Normally, the particles spew out from the center, but I've changed how the particles themselves look. They look a little like stars now. I would like to be able to have each particle rotate about its own z-axis while traveling. Everything I've tried makes the whole scene twirl around like it's going down the drain. Any ideas? Thanks, Michael Fritzius

Well, what I have is this:

int DrawGLScene(GLvoid)
{
glClearColor(0.3f, 0.3f, 0.3f,0.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
rotate += 0.5;

for (loop=0;loop<MAX_PARTICLES;loop++) //1000 particles
{
if (particle[loop].active)
{
float x=particle[loop].x; //get particle x position
float y=particle[loop].y; //get particle y position
float z=particle[loop].z+zoom; //get particle z position
//next three lines, rotate particle?
glLoadIdentity();
glTranslatef(x,y,z);
glRotatef(rotate, 0.0, 0.0, 1.0); //about z axis
glColor4f(r,g,b,fade);
glBegin(GL_TRIANGLE_STRIP); // Build Quad From A Triangle Strip
glTexCoord2d(1,1); glVertex3f(x+0.5f,y+0.5f,z); //
glTexCoord2d(0,1); glVertex3f(x-0.5f,y+0.5f,z);
glTexCoord2d(1,0); glVertex3f(x+0.5f,y-0.5f,z);
glTexCoord2d(0,0); glVertex3f(x-0.5f,y-0.5f,z);
glEnd(); // Done Building Triangle Strip

//rest of the code not relevant here

I thought that might work, but it results in the down-the-drain effect like I was saying. Each time the axes are translated to where the particle is, then the particle is drawn, then the axes are reset. But it still seems to rotate everything about a global z axis, rather than the z axis for each particle.

It is at the beginning (I think) like you said--rotate before the object is drawn.

Right?

That did the trick. Vielen dank :)

HA! I hadn't even noticed LC's nationality. I just felt like saying "thanks" in German.