Thread: Light woes or bad normals?

I'm not sure about D3D, but Iv'e gotten similar results doing the same thing under OGL (however mine wasn't quite that bad, as the sphere had a higher tesselation, and the sphere was much smaller).

I'd say either lightmap it, or use a shader.

-psychopath

Ok, I tried to lightmap it. Seems my GeForce 3 64MB card won't do it. Now I know this is wrong because my retail games get away with it.

So how do you light map w/o using shaders? Every time I try to use the fixed function pipeline or more than one sampler - I get no results. It's as if only sampler 0 is supported on my display driver.

This is a render state that has the light map in the alpha component of the texture. Doesn't work.

Code:

// Set the base texture operation and args.
  

  // Set the color operation.
  Device->SetTextureStageState(0, D3DTSS_COLOROP, D3DTOP_SELECTARG1);

  // Set argument 1 to the color operation.
  Device->SetTextureStageState(0, D3DTSS_COLORARG1,
       D3DTA_TEXTURE | D3DTA_ALPHAREPLICATE);

And this is the other method. Again, doesn't work.

Code:

// This example assumes that d3dDevice is a valid pointer to an
// IDirect3DDevice9 interface and that lptexLightMap is a valid
// pointer to a texture that contains RGB light map data.

// Set the light map texture as the first texture.
Device->SetTexture(0, Texture);

Device->SetTextureStageState( 0,D3DTSS_COLOROP, D3DTOP_MODULATE );

Device->SetTextureStageState( 0,D3DTSS_COLORARG1, D3DTA_TEXTURE );

Device->SetTextureStageState( 0,D3DTSS_COLORARG2, D3DTA_DIFFUSE );

Code:

// This example assumes that d3dDevice is a valid pointer to an
// IDirect3DDevice9 interface.
// lptexBaseTexture is a valid pointer to a texture.
// lptexDiffuseLightMap is a valid pointer to a texture that contains 
// RGB diffuse light map data.

// Set the base texture.
Device->SetTexture(0,Texture);

// Set the base texture operation and args.
Device->SetTextureStageState(0,D3DTSS_COLOROP,
       D3DTOP_MODULATE );

Device->SetTextureStageState(0,D3DTSS_COLORARG1, D3DTA_TEXTURE );

Device->SetTextureStageState(0,D3DTSS_COLORARG2, D3DTA_DIFFUSE );

// Set the diffuse light map.
Device->SetTexture(1,LightMap );

// Set the blend stage.
Device->SetTextureStageState(1, D3DTSS_COLOROP, D3DTOP_MODULATE );

Device->SetTextureStageState(1, D3DTSS_COLORARG1, D3DTA_TEXTURE );

Device->SetTextureStageState(1, D3DTSS_COLORARG2, D3DTA_CURRENT );

Last two right out of the SDK with my variables added. Still nothing.

Help, please.

Odd. Are you generating the lightmap at runtime? If so, you could try saving the lightmap data into a texture, and then loading that texture into your second texture unit. That would see if the data is being passed properly. After that, I don't really know, because it's probably D3D specific.

-psychopath

I've gotten this working in OpenGL, which is frustrating because you're doing the equivalent but with DirectX, so I don't know if I can help.


Perhaps try applying the lightmap when it's fully dark; I personally can't tell whether or not it's affecting the final render in any region.

For the first screenshot, how many light sources are contributing to the scene.

For the D3DXComputeNormals function how come you don't pass in a mesh pointer? I msdn'd it to see the parameters and stipulations and it at least seems to require a mesh pointer, and optionally the adjacency indices. It also states 'The input mesh must have the D3DFVF_NORMAL flag specified in its flexible vertex format (FVF).'

http://msdn.microsoft.com/library/de...utenormals.asp

good luck

Perhaps the texture coords are incorrect for the second texture unit? Just a thought. And as BobMcGee said, maybe it just the ambient light throwing it off.

Heres the lightmapping in OGL...I'm using OGL multitexture functions, and a default light.

I didn't post the actual function parameter lists. Everything is succeeding except for the end result. Even ramping the RGBs on the light map does not yield the correct results.

The second texture unit's coords are the same as the the first - because of the spherical mapping.

I finally got it working: Texture coords were incorrect. I placed code in the constructor of the vertex to copy the vertex for u and v to lu and lv, however when I spherical mapped the u and v, I was not setting the lu and lv. So the texture coords when I created the sphere was what the light map was getting. Doh!!!!!!!!!!!!!!!

So far it looks...um......quite good.

Thanks.

Make sure both textures are loaded correctly. You know your detail map is loaded correctly since you can plainly see it. Try using the lightmap texture as a detail map and seeing if it looks correct. Then it should be a matter of

Set Detail Map
SelectArg1 : TEXTURE
Set Light Map
Modulate : TEXTURE, CURRENT

You said something about the lightmap being in the alpha channel? I don't know what that's all about but you would need to handle that differently if that's the case. Otherwise the above method should work. Make sure you turn of the alpha stages if you aren't using them.