OpenGL: Lighting Crash

[MrHutch]

Hi guys,

Tempted to post this over on the GL forums but I thought it'd be worth a crack over here.

Have any of you GL programmers had a problem with GL_LIGHT0? I get a runtime crash when I enable it.

  // Set up perspective projection
  glMatrixMode( GL_PROJECTION );
  glLoadIdentity();
  gluPerspective( 30.f, 1.6f, 0.1f, 50.f );

  // Lighting
  glEnable( GL_LIGHTING );
  glEnable( GL_LIGHT0 );  // Causing crash... 

Granted, I'm just setting up the lighting and I haven't given the models normal data yet. That said, I'd expect the models to be fine with that; they'd just be black.

I've also enabled the GL_NORMAL_ARRAY client state. Haven't initialised the normal pointer yet, though. Again, I'd expect this to be fine and I'd have unlit models. Could be the cause of the problem, I guess.

One other thing. If I omit that line (the GL_LIGHT0 one, that is), my models are black, as I'd expect. And I can enable any of the other seven lights just fine.

[zb0S216C]

Someone already asked this question on SO: http://stackoverflow.com/a/13910634

_Wazzak

[shacktar]

Haven't initialised the normal pointer yet, though. Again, I'd expect this to be fine and I'd have unlit models. Could be the cause of the problem, I guess.

Yeah, that's probably the problem. You should send valid normals and see if that corrects the problem.

EDIT: It's very likely the problem (see link above)

One other thing. If I omit that line (the GL_LIGHT0 one, that is), my models are black, as I'd expect. And I can enable any of the other seven lights just fine.

GL_LIGHT0 is unique in that its diffuse component has a default white color. The other lights default to black. That could explain the different behaviour you have with the other lights.

[MrHutch]

Thanks guys.

I'll check this out tomorrow and mark as solved if it's sorted.

[MrHutch]

Just wanted to let you know that you were right guys. :-)

Only other issue was getting the vectors the wrong way around when calculating the cross products for my normals. All good now, though. :-)

http://s4.postimage.org/kykjrtqyl/basic_shaded_terrain.png

Note: Final terrain won't actually look like that - it's just a randomised height at the moment as I haven't implemented the correct algorithm yet. The idea was to build the renderer from the ground up first.

Cheers.