The Same shader gives different results on ATI and NVIDIA GPUs. float4x4 view_proj_matrix : ViewProjection; float4 view_position : ViewPosition; struct VS_OUTPUT { float4 Pos: POSITION; float3 normal: TEXCOORD0; float3 viewVec: TEXCOORD1; }; VS_OUTPUT Glass_Effect_Group_ComplexGlass_Object_Vertex_Shader_main(float4 Pos: POSITION, float3 normal: NORMAL) { VS_OUTPUT Out; Out.Pos = mul(view_proj_matrix, Pos); Out.normal = normal; Out.viewVec = view_position - Pos; return Out; } float refractionScale = float( 1.0 ); float4 baseColor = float4( 0.72, 0.70, 0.76, 1.00 ); float ambient = float( 0.20 ); float indexOfRefractionRatio = float( 0.14 ); float reflectionScale = float( 1.0 ); texture Snow_Environment_Tex; sampler Environment = sampler_state { Texture = (Snow_Environment_Tex); ADDRESSU = CLAMP; ADDRESSV = CLAMP; MAGFILTER = LINEAR; MINFILTER = LINEAR; MIPFILTER = LINEAR; }; sampler Rainbow; float4 Glass_Effect_Group_ComplexGlass_Object_Pixel_Shader_main(float3 normal: TEXCOORD0, float3 viewVec: TEXCOORD1) : COLOR { normal = normalize(normal); viewVec = normalize(viewVec); float3 reflVec = reflect(-viewVec, normal); float4 reflection = texCUBE(Environment, reflVec.xyz); float cosine = dot(viewVec, normal); float sine = sqrt(1 - cosine * cosine); float sine2 = saturate(indexOfRefractionRatio * sine); float cosine2 = sqrt(1 - sine2 * sine2); float3 x = -normal; float3 y = normalize(cross(cross(viewVec, normal), normal)); float3 refrVec = x * cosine2 + y * sine2; float4 refraction = texCUBE( Environment,refrVec.xyz); float4 refl = reflectionScale * reflection; float4 refr = refractionScale * refraction * baseColor; return sine * refl + (1 - sine2) * refr + sine2 * ambient; } //--------------------------------------------------------------// // Technique Section for Glass Effect Group //--------------------------------------------------------------// technique ComplexGlass { pass Object { ZENABLE = TRUE; CULLMODE = CCW; VertexShader = compile vs_2_0 Glass_Effect_Group_ComplexGlass_Object_Vertex_Shader_main(); PixelShader = compile ps_2_0 Glass_Effect_Group_ComplexGlass_Object_Pixel_Shader_main(); } } Nvidia result: http://www.gamedev.ru/images/?id=30781 ATI result: http://www.gamedev.ru/images/?id=30782

here GPU ShaderAnalyzer 1.40
And in RenderMonkey
- nothing :(