Pulling my hair out over D3D11 lighting bug

Phillip Clark · 2012-12-09T20:52:25

I have a simple model loaded and a point light source that I am trying to get to work correctly, but it's just not happening. I have probably spent around 12 hours over the past two days trying to figure out what is wrong, and I'm starting to get really frustrated, so I thought I would ask here as a last resort. I have checked and double checked my lighting equation many times with at least 3 different sources. At the moment I am using constant lighting coefficient so that I know for a fact my object will be lit no matter what the distance. My light is EXPLICITLY fixed at the -30.0 position on the Z-axis, yet my object appears as if it is lit from a different direction. My camera is located at ( 0.0, 0.0, -20.0 ) so that I can verify the model is not swallowing the light, and it is not. The light is plenty far away from my model. I've changed the light/camera distance many times and have gotten the same result. The entire front side of my object should be lit, instead it is lit from a different angle. I use the DirectXMath library and I was VERY, VERY careful to store the const buffer matrices correctly and with the right alignment. I also made sure my HLSL byte alignment was correct by using float4. I use the row-major compiler options for HLSL so I do not need to use matrix transpose, and my code reflects that. Please give my code a look and tell me where I've gone wrong, because I obviously cannot figure it out! Bugged lighting: [attachment=12680:bug.jpg] Matrix update function: [attachment=12677:update.jpg] Vertex shader: [attachment=12678:vs.jpg] Pixel shader: [attachment=12679:ps.jpg]