From c48d752ad4cea3093dcafea880681a5b01cefc55 Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Wed, 30 Aug 2017 15:58:19 +0200
Subject: [PATCH] Utility/MeshLoader: Fix pre-transformation matrix not
 affecting normal and tangents in some cases (Fix #131)

---
 plugins/Assimp/Plugin.cpp                | 10 ++++++++--
 src/Nazara/Utility/Formats/MD2Loader.cpp |  5 ++++-
 src/Nazara/Utility/Formats/OBJLoader.cpp |  8 +++++++-
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/plugins/Assimp/Plugin.cpp b/plugins/Assimp/Plugin.cpp
index 744434137..7834e0019 100644
--- a/plugins/Assimp/Plugin.cpp
+++ b/plugins/Assimp/Plugin.cpp
@@ -202,6 +202,12 @@ bool Load(Mesh* mesh, Stream& stream, const MeshParams& parameters)
 				indexMapper.Unmap();
 
 				// Vertex buffer
+
+				// Make sure the normal/tangent matrix won't rescale our vectors
+				Nz::Matrix4f normalTangentMatrix = parameters.matrix;
+				if (normalTangentMatrix.HasScale())
+					normalTangentMatrix.ApplyScale(1.f / normalTangentMatrix.GetScale());
+
 				VertexBufferRef vertexBuffer = VertexBuffer::New(VertexDeclaration::Get(VertexLayout_XYZ_Normal_UV_Tangent), vertexCount, parameters.storage, 0);
 				BufferMapper<VertexBuffer> vertexMapper(vertexBuffer, BufferAccess_WriteOnly);
 
@@ -214,8 +220,8 @@ bool Load(Mesh* mesh, Stream& stream, const MeshParams& parameters)
 					aiVector3D uv = (iMesh->HasTextureCoords(0)) ? iMesh->mTextureCoords[0][j] : aiVector3D(0.f);
 
 					vertex->position = parameters.matrix * Vector3f(position.x, position.y, position.z);
-					vertex->normal.Set(normal.x, normal.y, normal.z);
-					vertex->tangent.Set(tangent.x, tangent.y, tangent.z);
+					vertex->normal = normalTangentMatrix.Transform({normal.x, normal.y, normal.z}, 0.f);
+					vertex->tangent = normalTangentMatrix.Transform({tangent.x, tangent.y, tangent.z}, 0.f);
 					vertex->uv.Set(parameters.texCoordOffset + Vector2f(uv.x, uv.y) * parameters.texCoordScale);
 					vertex++;
 				}
diff --git a/src/Nazara/Utility/Formats/MD2Loader.cpp b/src/Nazara/Utility/Formats/MD2Loader.cpp
index 76ee1c1ea..9008a22ad 100644
--- a/src/Nazara/Utility/Formats/MD2Loader.cpp
+++ b/src/Nazara/Utility/Formats/MD2Loader.cpp
@@ -219,13 +219,16 @@ namespace Nz
 			Nz::Matrix4f matrix = Matrix4f::Transform(translate, rotationQuat, scale);
 			matrix *= parameters.matrix;
 
+			Nz::Matrix4f normalMatrix = Matrix4f::Rotate(rotationQuat);
+			normalMatrix *= parameters.matrix;
+
 			for (unsigned int v = 0; v < header.num_vertices; ++v)
 			{
 				const MD2_Vertex& vert = vertices[v];
 				Vector3f position = matrix * Vector3f(vert.x, vert.y, vert.z);
 
 				vertex->position = position;
-				vertex->normal = rotationQuat * md2Normals[vert.n];
+				vertex->normal = normalMatrix.Transform(md2Normals[vert.n], 0.f);
 
 				vertex++;
 			}
diff --git a/src/Nazara/Utility/Formats/OBJLoader.cpp b/src/Nazara/Utility/Formats/OBJLoader.cpp
index d7dd15d14..b9573b5d5 100644
--- a/src/Nazara/Utility/Formats/OBJLoader.cpp
+++ b/src/Nazara/Utility/Formats/OBJLoader.cpp
@@ -244,6 +244,12 @@ namespace Nz
 				indexMapper.Unmap(); // Pour laisser les autres tâches affecter l'index buffer
 
 				// Remplissage des vertices
+
+				// Make sure the normal matrix won't rescale our normals
+				Nz::Matrix4f normalMatrix = parameters.matrix;
+				if (normalMatrix.HasScale())
+					normalMatrix.ApplyScale(1.f / normalMatrix.GetScale());
+
 				bool hasNormals = true;
 				bool hasTexCoords = true;
 				BufferMapper<VertexBuffer> vertexMapper(vertexBuffer, BufferAccess_WriteOnly);
@@ -259,7 +265,7 @@ namespace Nz
 					vertex.position = Vector3f(parameters.matrix * vec);
 
 					if (vertexIndices.normal > 0)
-						vertex.normal = normals[vertexIndices.normal-1];
+						vertex.normal = normalMatrix.Transform(normals[vertexIndices.normal - 1], 0.f);
 					else
 						hasNormals = false;