diff --git a/src/core/hle/D3D8/Direct3D9/CxbxPixelShaderTemplate.hlsl b/src/core/hle/D3D8/Direct3D9/CxbxPixelShaderTemplate.hlsl
index a0c7db56a..b69b93393 100644
--- a/src/core/hle/D3D8/Direct3D9/CxbxPixelShaderTemplate.hlsl
+++ b/src/core/hle/D3D8/Direct3D9/CxbxPixelShaderTemplate.hlsl
@@ -53,6 +53,7 @@ uniform const float4 FC0 : register(c16); // Note : Maps to PSH_XBOX_CONSTANT_FC
 uniform const float4 FC1 : register(c17); // Note : Maps to PSH_XBOX_CONSTANT_FC1, must be generated as argument to xfc instead of C1
 uniform const float4 BEM[4] : register(c19); // Note : PSH_XBOX_CONSTANT_BEM for 4 texture stages
 uniform const float4 LUM[4] : register(c23); // Note : PSH_XBOX_CONSTANT_LUM for 4 texture stages
+uniform const float  FRONTFACE_FACTOR : register(c27); // Note : PSH_XBOX_CONSTANT_LUM for 4 texture stages
 
 
 #define CM_LT(c) if(c < 0) clip(-1); // = PS_COMPAREMODE_[RSTQ]_LT
@@ -335,11 +336,14 @@ PS_OUTPUT main(const PS_INPUT xIn)
 	float3 s;              // Actual texture coordinate sampling coordinates (temporary)
 	float4 v;              // Texture value (temporary)
 
+	// Determine if this is a front face or backface
+	bool isFrontFace = (xIn.iFF * FRONTFACE_FACTOR) >= 0;
+
 	// Initialize variables
 	r0 = r1 = black; // Note : r0.a/r1.a will be overwritten by t0.a/t1.a (opaque_black will be retained for PS_TEXTUREMODES_NONE)
 	// Note : VFACE/FrontFace has been unreliable, investigate again if some test-case shows bland colors
-	v0 = xIn.iFF > 0 ? xIn.iD0 : xIn.iB0; // Diffuse front/back
-	v1 = xIn.iFF > 0 ? xIn.iD1 : xIn.iB1; // Specular front/back
+	v0 = isFrontFace ? xIn.iD0 : xIn.iB0; // Diffuse front/back
+	v1 = isFrontFace ? xIn.iD1 : xIn.iB1; // Specular front/back
 	fog = float4(c_fog.rgb, xIn.iFog); // color from PSH_XBOX_CONSTANT_FOG, alpha from vertex shader output / pixel shader input
 
 	// Xbox shader program
diff --git a/src/core/hle/D3D8/XbConvert.cpp b/src/core/hle/D3D8/XbConvert.cpp
index 36899b2d7..1ea57bd1b 100644
--- a/src/core/hle/D3D8/XbConvert.cpp
+++ b/src/core/hle/D3D8/XbConvert.cpp
@@ -1504,8 +1504,8 @@ const RenderStateInfo DxbxRenderStateInfo[1+xbox::X_D3DRS_DONOTCULLUNCOMPRESSED]
 	{ "D3DRS_VERTEXBLEND"                 /*= 137*/, 3424, xtD3DVERTEXBLENDFLAGS, NV2A_SKIN_MODE, D3DRS_VERTEXBLEND },
 	{ "D3DRS_FOGCOLOR"                    /*= 138*/, 3424, xtD3DCOLOR,            NV2A_FOG_COLOR, D3DRS_FOGCOLOR }, // SwapRgb
 	{ "D3DRS_FILLMODE"                    /*= 139*/, 3424, xtD3DFILLMODE,         NV2A_POLYGON_MODE_FRONT, D3DRS_FILLMODE },
-	{ "D3DRS_BACKFILLMODE"                /*= 140*/, 3424, xtD3DFILLMODE,         0 }, // nsp.
-	{ "D3DRS_TWOSIDEDLIGHTING"            /*= 141*/, 3424, xtBOOL,                NV2A_POLYGON_MODE_BACK }, // nsp.
+	{ "D3DRS_BACKFILLMODE"                /*= 140*/, 3424, xtD3DFILLMODE,         NV2A_POLYGON_MODE_BACK }, // nsp.
+	{ "D3DRS_TWOSIDEDLIGHTING"            /*= 141*/, 3424, xtBOOL,                0 }, // nsp.  // FIXME map from NV2A_LIGHT_MODEL
 	{ "D3DRS_NORMALIZENORMALS"            /*= 142*/, 3424, xtBOOL,                NV2A_NORMALIZE_ENABLE, D3DRS_NORMALIZENORMALS },
 	{ "D3DRS_ZENABLE"                     /*= 143*/, 3424, xtBOOL,                NV2A_DEPTH_TEST_ENABLE, D3DRS_ZENABLE }, // D3DZBUFFERTYPE?
 	{ "D3DRS_STENCILENABLE"               /*= 144*/, 3424, xtBOOL,                NV2A_STENCIL_ENABLE, D3DRS_STENCILENABLE },
diff --git a/src/core/hle/D3D8/XbPixelShader.cpp b/src/core/hle/D3D8/XbPixelShader.cpp
index f092c9996..e9e68a1e6 100644
--- a/src/core/hle/D3D8/XbPixelShader.cpp
+++ b/src/core/hle/D3D8/XbPixelShader.cpp
@@ -630,8 +630,10 @@ constexpr int PSH_XBOX_CONSTANT_FOG = PSH_XBOX_CONSTANT_FC1 + 1; // = 18
 constexpr int PSH_XBOX_CONSTANT_BEM = PSH_XBOX_CONSTANT_FOG + 1; // = 19..22
 // Bump map Luminance registers
 constexpr int PSH_XBOX_CONSTANT_LUM = PSH_XBOX_CONSTANT_BEM + 4; // = 23..26
+// Which winding order to consider as the front face
+constexpr int PSH_XBOX_CONSTANT_FRONTFACE_FACTOR = PSH_XBOX_CONSTANT_LUM + 4; // = 27
 // This concludes the set of constants that need to be set on host :
-constexpr int PSH_XBOX_CONSTANT_MAX = PSH_XBOX_CONSTANT_LUM + 4; // = 27
+constexpr int PSH_XBOX_CONSTANT_MAX = PSH_XBOX_CONSTANT_FRONTFACE_FACTOR + 1; // = 28
 
 void DxbxUpdateActivePixelShader() // NOPATCH
 {
@@ -768,6 +770,21 @@ void DxbxUpdateActivePixelShader() // NOPATCH
   }
 #endif
 
+  // Control whether to use front or back diffuse/specular colours
+  // This factor should be multipled with VFACE
+  // Test cases:
+  // Amped (snowboard trails should use front colours, but use both CW and CCW winding)
+  // TwoSidedLighting sample
+  float frontfaceFactor = 0; // 0 == always use the front colours
+  if (XboxRenderStates.GetXboxRenderState(xbox::X_D3DRS_TWOSIDEDLIGHTING)) {
+	  LOG_TEST_CASE("Two sided lighting");
+	  // VFACE is positive for clockwise faces
+	  // If Xbox designates counter-clockwise as front-facing, we invert VFACE
+	  auto cwFrontface = XboxRenderStates.GetXboxRenderState(xbox::X_D3DRS_FRONTFACE) == 0x900; // clockwise;
+	  frontfaceFactor = cwFrontface ? 1 : -1;
+  }
+  fColor[PSH_XBOX_CONSTANT_FRONTFACE_FACTOR].r = frontfaceFactor;
+
   // Assume all constants are in use (this is much easier than tracking them for no other purpose than to skip a few here)
   // Read the color from the corresponding render state slot :
   // Set all host constant values using a single call: