We were force normalising the result of matrix * normal, which looked correct in most cases. But this didn't preserve the scaling of the matrix, or the scaling of the model normals which resulted in many over bright areas. On it's own this generally worked, but games like Star Wars looked quite broken. Harry correctly figured out if you scale these normals by the scaling value that is sometimes present in the culling nodes the lighting looks correct. Still more work to do to correctly figure out the model3's lighting model.

Src/Graphics/New3D/Model.cpp

@@ -8,6 +8,7 @@ NodeAttributes::NodeAttributes()
 	currentTexOffsetY	= 0;
 	currentPage			= 0;
 	currentClipStatus	= Clip::INTERCEPT;
+	currentModelScale	= 1.0f;
 }
 
 bool NodeAttributes::Push()
@@ -25,8 +26,9 @@ bool NodeAttributes::Push()
 	na.texOffsetX	= currentTexOffsetX;
 	na.texOffsetY	= currentTexOffsetY;
 	na.clip			= currentClipStatus;
+	na.modelScale	= currentModelScale;
 
-	m_vecAttribs.push_back(na);
+	m_vecAttribs.emplace_back(na);
 
 	return true;
 }
@@ -37,12 +39,13 @@ bool NodeAttributes::Pop()
 		return false;	// check for underflow
 	}
 
-	auto last = &m_vecAttribs.back();
+	auto &last = m_vecAttribs.back();
 
-	currentPage			= last->page;
-	currentTexOffsetX	= last->texOffsetX;
-	currentTexOffsetY	= last->texOffsetY;
-	currentClipStatus	= last->clip;
+	currentPage			= last.page;
+	currentTexOffsetX	= last.texOffsetX;
+	currentTexOffsetY	= last.texOffsetY;
+	currentClipStatus	= last.clip;
+	currentModelScale	= last.modelScale;
 
 	m_vecAttribs.pop_back();
 
@@ -60,6 +63,7 @@ void NodeAttributes::Reset()
 	currentTexOffsetX	= 0;
 	currentTexOffsetY	= 0;
 	currentClipStatus	= Clip::INTERCEPT;
+	currentModelScale	= 1.0f;
 
 	m_vecAttribs.clear();
 }

Src/Graphics/New3D/Model.h

@@ -118,6 +118,9 @@ struct Model
 	//matrices
 	float modelMat[16];
 	float determinant;				// we check if the determinant of the matrix is negative, if it is, the matrix will swap the axis order
+
+	//model scale step 1.5+
+	float scale = 1.0f;
 };
 
 struct Viewport
@@ -166,6 +169,7 @@ public:
 	int currentTexOffsetY;
 	int currentPage;
 	Clip currentClipStatus;
+	float currentModelScale;
 
 private:
 
@@ -175,6 +179,7 @@ private:
 		int texOffsetY;
 		int page;
 		Clip clip;
+		float modelScale;
 	};
 	std::vector<NodeAttribs> m_vecAttribs;
 };

Src/Graphics/New3D/New3D.cpp

@@ -409,6 +409,7 @@ bool CNew3D::DrawModel(UINT32 modelAddr)
 	m->textureOffsetX = m_nodeAttribs.currentTexOffsetX;
 	m->textureOffsetY = m_nodeAttribs.currentTexOffsetY;
 	m->page = m_nodeAttribs.currentPage;
+	m->scale = m_nodeAttribs.currentModelScale;
 
 	if (!cached) {
 		CacheModel(m, modelAddress);
@@ -463,6 +464,12 @@ void CNew3D::DescendCullingNode(UINT32 addr)
 	m_nodeAttribs.Push();	// save current attribs
 
 	if (!m_offset) {		// Step 1.5+
+		
+		float modelScale = *(float *)&node[1];
+		if (modelScale) {
+			m_nodeAttribs.currentModelScale = modelScale;
+		}
+
 		// apply texture offsets, else retain current ones
 		if ((node[0x02] & 0x8000))	{
 			int tx = 32 * ((node[0x02] >> 7) & 0x3F);
@@ -477,7 +484,7 @@ void CNew3D::DescendCullingNode(UINT32 addr)
 	m_modelMat.PushMatrix();
 
 	// apply translation vector
-	if ((node[0x00] & 0x10)) {
+	if (node[0x00] & 0x10) {
 		float x = *(float *)&node[0x04 - m_offset];
 		float y = *(float *)&node[0x05 - m_offset];
 		float z = *(float *)&node[0x06 - m_offset];

Src/Graphics/New3D/R3DShader.cpp

@@ -9,6 +9,7 @@ static const char *vertexShaderR3D = R"glsl(
 uniform float	fogIntensity;
 uniform float	fogDensity;
 uniform float	fogStart;
+uniform float	modelScale;
 
 //outputs to fragment shader
 varying float	fsFogFactor;
@@ -19,7 +20,7 @@ varying vec4	fsColor;
 void main(void)
 {
 	fsViewVertex	= vec3(gl_ModelViewMatrix * gl_Vertex);
-	fsViewNormal	= normalize(gl_NormalMatrix * gl_Normal);
+	fsViewNormal	= (mat3(gl_ModelViewMatrix) * gl_Normal) / modelScale;
 	float z			= length(fsViewVertex);
 	fsFogFactor		= fogIntensity * clamp(fogStart + z * fogDensity, 0.0, 1.0);
 
@@ -193,6 +194,7 @@ void R3DShader::Start()
 	m_lightEnabled		= false;
 	m_layered			= false;
 	m_textureInverted	= false;
+	m_modelScale		= 1.0f;
 
 	m_baseTexSize[0] = 0;
 	m_baseTexSize[1] = 0;
@@ -255,6 +257,7 @@ bool R3DShader::LoadShader(const char* vertexShader, const char* fragmentShader)
 	m_locSpotRange		= glGetUniformLocation(m_shaderProgram, "spotRange");
 	m_locSpotColor		= glGetUniformLocation(m_shaderProgram, "spotColor");
 	m_locSpotFogColor	= glGetUniformLocation(m_shaderProgram, "spotFogColor");
+	m_locModelScale		= glGetUniformLocation(m_shaderProgram, "modelScale");
 
 	return success;
 }
@@ -414,6 +417,11 @@ void R3DShader::SetModelStates(const Model* model)
 		}
 	}
 
+	if (m_dirtyModel || model->scale != m_modelScale) {
+		glUniform1f(m_locModelScale, model->scale);
+		m_modelScale = model->scale;
+	}
+
 	m_matDet		= test;
 	m_dirtyModel	= false;
 }

Src/Graphics/New3D/R3DShader.h

@@ -53,7 +53,8 @@ private:
 
 	// cached model values
 	enum class MatDet { notset, negative, positive, zero };
-	MatDet m_matDet;
+	MatDet	m_matDet;
+	float	m_modelScale;
 
 	// are our cache values dirty
 	bool	m_dirtyMesh;
@@ -67,7 +68,7 @@ private:
 	GLint m_locFogAttenuation;
 	GLint m_locFogAmbient;
 
-	// lighting
+	// lighting / other
 	GLint m_locLighting;
 	GLint m_locLightEnable;
 	GLint m_locLightClamp;
@@ -77,6 +78,9 @@ private:
 	GLint m_locSpotRange;
 	GLint m_locSpotColor;
 	GLint m_locSpotFogColor;
+
+	// model uniforms
+	GLint m_locModelScale;
 };
 
 } // New3D