Please Help: Problems Drawing disks

OpenGL Development JOGL Development
#1

Hello,
i’m new to opengl and i have the following problem
my reshape function is as follows:
gl.glViewport(0, 0, bounds.width, bounds.height);
GLU glu = new GLU();
gl.glLoadIdentity();
glu.gluPerspective(90.0f, fAspect, 0f, 200.0f);
glu.gluLookAt(0,-0.2f,0.5f, 0.0, 0.0, 0.0, 0.0,1, 0.0);
gl.glMatrixMode(GL.GL_MODELVIEW);
gl.glLoadIdentity();

then i draw a filled disk (with GLU) or an other filled object which has flattenized curves.

with glu.gluLookAt(0,0,0.5f, 0.0, 0.0, 0.0, 0.0,1, 0.0);

all is fine. i have a 2 d view from above on the filled disk.

if i change perspektive
with glu.gluLookAt(0,-0.2f,0.5f, 0.0, 0.0, 0.0, 0.0,1, 0.0);
there are triangular holes in the disk.
that means the disk is not filled correctly.

May be i have not done the right things before drawing?

(I’m using org.eclipse.swt.opengl.GLCanvas for drawing with JOGL)

thanks and best regards
christian

#2

This might be unrelated, but it’s generally a very bad idea to have the near clipping plane set to 0, as that really messes up the z buffer.

#3

hello,
ok super, this was the bug in the code.
all works fine (of course) by setting the near value f.e. to 0.1
thanks a lot and
best regards
christian