I draw the wings on my airplane like this: Basically, it's a whole bunch of transformations to get to the places to draw the items (I've cut loads of to make it easier to read) ===================================== glTranslatef(xPos, yPos, zPos); glRotatef(pitch, 1.0, 0.0, 0.0); etc //draw cylinder part of airplane (not shown for brevity) //now go to where wing is supposed to be glTranslatef(AIRPLANE_RADIUS, 0.0, AIRPLANE_TAILFIN_LENGTH); glScalef(TAILFIN_LENGTH, TAILFIN_LENGTH,TAILFIN_LENGTH); //draw the wing (simplified) glBegin(GL_TRIANGLES); //POINT ONE - GET MODEL MATRIX HERE ??? glVertex3f(0.0f, 0.0f, 0.0f); //FIRST POINT ON WING glVertex3f(1.0f, 0.0f, 0.0f); glVertex3f(1.0f, 1.0f, 0.0f); glEnd(); ===================================== Now, I assume that if I want to know the precise vector of the first point on the wing I can simply multiply the vector at the first point on the wing (ie (0.0f, 0.0f, 0.0f) ) with the model matrix at POINT ONE ?? I do that - then in order to check I've got it right I draw a big fat sphere at that point by glPushMatrix glLoadIdentity(); glTranslatef(values from model matrix multiply); //draw big sphere here !!! glPopMatrix(); Of course the sphere isn't there !! So what am I doing wrong ??? If I can overcome this problem then I'm nearly finished. cheers Ade

anyone have any ideas ?!

cheers

I missed a bit out - the matrix model isn't obtained within a Begin and End section.
also, I simplified the code here to make it easier to understand.

What I actually have done in order to obtain the new vertices is to:

glPushMatrix
glLoadidentity
//repeat all the transformations I did on the airplane
//to get to the drawing the wing part

get the modelmatrix
multiply the vector (0.0, 0.0, 0.0) with this.
write a sphere at this new point to check if my method
is correct.
glPopMatrix


Obviously the sphere doesn't come out even though I made it enormous !

cheers