No light in my scene

[strange]

Hi,

I have a problem with setting up the light in my scene. I just want to have some nice flat surfaces without textures that get shaded by a light.
Is there anyting I did forget or did wrong in my code because the objects stay totaly black:

GL.glLightModel(GL.GL_LIGHT_MODEL_AMBIENT, temp.asFloatBuffer().put(ambientLight));
GL.glEnable(GL.GL_COLOR_MATERIAL);

   
GL.glLightfv(GL.GL_LIGHT0, GL.GL_AMBIENT, temp.asFloatBuffer().put(ambientLight0));
GL.glLightfv(GL.GL_LIGHT0, GL.GL_DIFFUSE, temp.asFloatBuffer().put(diffuseLight0));
GL.glLightfv(GL.GL_LIGHT0, GL.GL_POSITION,temp.asFloatBuffer().put(lightPos0));
GL.glEnable(GL.GL_LIGHT0);
GL.glEnable(GL.GL_LIGHTING);

and this in front of my objects:

GL.glColorMaterial(GL.GL_FRONT, GL.GL_AMBIENT_AND_DIFFUSE);

Thanks for help

[Mojomonkey]

Are you setting up your normals?

[princec]

You must flip() your buffers after put()ting stuff in them. This sets the buffer's position and limit correctly which is what we pass into OpenGL.

Cas

[strange]

That sounds pretty much like a problem  :wink:

I did the necesary changes in my code but now I have compilingproblems. An exception occured in the native code.

The code looks like:
 public static FloatBuffer fbuff = FloatBuffer.allocate(16);
 fbuff.put(diffuseLight0).flip();
 GL.glLightfv(GL.GL_LIGHT0, GL.GL_DIFFUSE, fbuff);


Oh my god!

[Optus]

Don't know if it will be your end-all fix, but buffers passed to OpenGL must be allocated with allocateDirect(), not the allocate() method.

[cfmdobbie]

Try this instead:

public static FloatBuffer fbuff = ByteBuffer.allocateDirect(16).order(ByteOrder.nativeOrder()).asFloatBuffer();
fbuff.put(diffuseLight0).flip();
GL.glLightfv(GL.GL_LIGHT0, GL.GL_DIFFUSE, fbuff);

[strange]

Great, finaly the light works. I thank you guys very much.

But this is a very complicated way of seting up the light.
Does anyone have a more "normal" way of doing this?

[Optus]

I haven't used any of OpenGL's lighting for any lighting purposes in my current project. I have either used lightmapping, using ARB multitexture, or by calculating shade values and coloring geometry with the glColor3f() method at render-time.

[princec]

There is no easier way of setting up lights in OpenGL. However, coz you're a Java programmer, you will write a Light class that does it for you and squirrels away the nasty code so you can't see it any more, and you'll forget all about how it works in a few weeks and just get on with some other problem

Cas