Improved patch mesh surface normals.

3 files changed, 92 insertions, 31 deletions

diff --git a/src/model/mapfile.cc b/src/model/mapfile.cc
index 76a75a9..bf41cb4 100644
--- a/src/model/mapfile.cc
+++ b/src/model/mapfile.cc
@@ -27,8 +27,8 @@ const float MIN_DELTA = 10e-10;
 
 // from radiant tools/quake3/q3map2/map.c
 math::Vector3f texture_baseaxis[18] = {
-	// normal		texture plane
-	math::Vector3f(0, 0, 1), 	math::Vector3f(1, 0, 0), math::Vector3f(0, -1, 0),	// floor
+	// normal			texture plane
+	math::Vector3f(0, 0, 1),	math::Vector3f(1, 0, 0), math::Vector3f(0, -1, 0),	// floor
 	math::Vector3f(0, 0, -1),	math::Vector3f(1, 0, 0), math::Vector3f(0, -1, 0),	// ceiling
 	math::Vector3f(1, 0, 0),	math::Vector3f(0, 1, 0), math::Vector3f(0, 0, -1),	// west wall
 	math::Vector3f(-1, 0, 0),	math::Vector3f(0, 1, 0), math::Vector3f(0, 0, -1),	// east wall
@@ -328,7 +328,6 @@ bool MapFile::read_patchdef()
 			}
 			
 			patchvertices[r][c].assign(x, y, z);
-			patchvertices[r][c] *= SCALE;
 		}
 		
 		if (!(linestream >> word)) {
@@ -388,42 +387,111 @@ bool MapFile::read_patchdef()
 	}
 	
 	// load patch data into the model geometry
-	// the patch is a set of quadratic B-splines with m = n =2
+	// the patch is a set of quadratic B-splines with m = n = 2
+	// see http://en.wikipedia.org/wiki/Bézier_surface
+	// http://www.cc.gatech.edu/classes/AY2002/cs4451_spring/groups/group3/index.html#bpatches2
+	//
+	// patchvertices[][] are the control points as read from the .map file
+	// mesh[][] is a subdivideXsubdivide quad mesh calculated for each set of 9 control points in the patch
+	
 	// TODO texture coordinates, normals
 	
 	// TODO variable sibdivision
 	const size_t subdivide = 4;
-	const float binom[3] = {1, 2, 1};
+	const float binom[3] = {1.0f, 2.0f, 1.0f};
 	
 	for (size_t r = 0; r < rows-2; r +=2 ) {
 		for (size_t c = 0; c < columns -2; c += 2) {
+			
 			math::Vector3f mesh[subdivide + 1][subdivide +1];
+			math::Vector3f meshnormals[subdivide + 1][subdivide +1];
+			math::Vector3f patchnormals[3][3];
+			
+			patchnormals[0][0].assign(math::normal(patchvertices[r+0][c+0], patchvertices[r+1][c+0], patchvertices[r+0][c+1]));
+			patchnormals[0][2].assign(math::normal(patchvertices[r+0][c+2], patchvertices[r+0][c+1], patchvertices[r+1][c+2]));
+			patchnormals[2][2].assign(math::normal(patchvertices[r+2][c+2], patchvertices[r+1][c+2], patchvertices[r+2][c+1]));
+			patchnormals[2][0].assign(math::normal(patchvertices[r+2][c+0], patchvertices[r+2][c+1], patchvertices[r+1][c+0]));
+			
+			patchnormals[0][1].assign(patchnormals[0][0] + patchnormals[0][2]);
+			patchnormals[0][1] *= 0.5f;
+			patchnormals[0][1].normalize();
+			
+			patchnormals[2][1].assign(patchnormals[2][0] + patchnormals[2][2]);
+			patchnormals[2][1] *= 0.5f;
+			patchnormals[2][1].normalize();
+			
+			patchnormals[1][0].assign(patchnormals[0][0] + patchnormals[2][0]);
+			patchnormals[1][0] *= 0.5f;
+			patchnormals[1][0].normalize();
+			
+			patchnormals[1][2].assign(patchnormals[0][2] + patchnormals[2][2]);
+			patchnormals[1][2] *= 0.5f;
+			patchnormals[1][2].normalize();
+			
+			patchnormals[1][1].assign(patchnormals[0][1] + patchnormals[2][1] + patchnormals[1][0] + patchnormals[1][2]);
+			patchnormals[1][1] *= 0.25f;
+			patchnormals[1][1].normalize();
 			
 			for (size_t i = 0; i <= subdivide; i++) {
 				const float u = (float) i / (float) subdivide;
 				for (size_t j = 0; j <= subdivide; j++) {
 					const float v = (float) j / (float) subdivide;
+					//math::Vector3f tan_u;
+					//math::Vector3f tan_v;
 					
 					for (size_t mi = 0; mi < 3; mi++) {
 						for (size_t mj = 0; mj < 3; mj++) {
 							mesh[i][j] +=
 								patchvertices[r+mi][c+mj] * 
-								binom[mi] * pow (u,mi) * pow(1.0f - u, 2-mi) * 
-								binom[mj] * pow (v,mj) * pow(1.0f - v, 2-mj);
+								binom[mi] * powf (u, (float) mi) * powf(1.0f - u, 2.0f - (float) mi) * 
+								binom[mj] * powf (v, (float) mj) * powf(1.0f - v, 2.0f - (float) mj);
+							
+							meshnormals[i][j] +=
+								patchnormals[mi][mj] * 
+								binom[mi] * powf (u, (float) mi) * powf(1.0f - u, 2.0f - (float) mi) * 
+								binom[mj] * powf (v, (float) mj) * powf(1.0f - v, 2.0f - (float) mj);
+							/*	
+							tan_u +=
+								patchvertices[r+mi][c+mj] * 
+								binom[mi] * (
+									((float) mi) * powf(u, (float) mi - 1.0f) * powf(1.0f - u, 2.0f - (float) mi) +
+									((float) mi - 2.0f) * powf(u, (float) mi) * powf(1.0f - u, 1.0f - (float) mi)
+								) *
+								binom[mj] * powf (v, (float) mj) * powf(1.0f - v, 2.0f - (float) mj);
+								
+							tan_v +=
+								patchvertices[r+mi][c+mj] * 
+								binom[mi] * powf (u, (float) mi) * powf(1.0f - u, 2.0f - (float) mi) * 
+								binom[mj] * (
+									((float) mj) * powf(v, (float) mj - 1.0f) * powf(1.0f - v, 2.0f - (float) mj) +
+									((float) mj - 2.0f) * powf(v, (float) mj) * powf(1.0f - v, 1.0f - (float) mj)
+								);
+							*/
 						}
 					}
-				}
+
+					//meshnormals[i][j].assign(math::crossproduct(tan_u, tan_v));
+					meshnormals[i][j].normalize();
+					class_box.expand(mesh[i][j] * SCALE);
+				}			
 			}
-				
+			
+			const math::Vector3f zero;
 			for (size_t i = 0; i < subdivide; i++) {
 				for (size_t j = 0; j < subdivide; j++) {
 					Quad *quad = new Quad(
-							mesh[i+1][j+1],
-							mesh[i][j+1],
-							mesh[i][j],
-							mesh[i+1][j],
-							math::normal(mesh[i][j+1], mesh[i][j], mesh[i+1][j+1])
+							mesh[i+1][j+1] * SCALE,
+							mesh[i][j+1] * SCALE,
+							mesh[i][j] * SCALE,
+							mesh[i+1][j] * SCALE,
+							zero
 					);
+					
+					quad->n0().assign(meshnormals[i+1][j+1]);
+					quad->n1().assign(meshnormals[i][j+1]);
+					quad->n2().assign(meshnormals[i][j]);
+					quad->n3().assign(meshnormals[i+1][j]);
+					
 					primitives->add_quad(quad);
 				}
 			}
@@ -811,7 +879,7 @@ void MapFile::make_brushface(Face *face)
 			primitives = (*mit).second;
 		}
 
-		// scale vertices and calculate the bounding box
+		// add vertices to the bounding box
 		for (std::vector<Vector3f *>::iterator it = vl.begin(); it != vl.end(); it++) {
 			class_box.expand(*(*it) * SCALE);
 		}
@@ -1103,10 +1171,10 @@ void MapFile::load_fragmentgroup(Model *model, const FragmentGroup::Type class_t
 				Quad *quad = (*quad_it);
 				if (!quad->detail()) {
 					size_t count = 0;
-					count += fragment->add_vertex(quad->v0() - translation, quad->normal(), quad->t0(), false);
-					count += fragment->add_vertex(quad->v1() - translation, quad->normal(), quad->t1(), false);
-					count += fragment->add_vertex(quad->v2() - translation, quad->normal(), quad->t2(), false);
-					count += fragment->add_vertex(quad->v3() - translation, quad->normal(), quad->t3(), false);
+					count += fragment->add_vertex(quad->v0() - translation, quad->n0(), quad->t0(), false);
+					count += fragment->add_vertex(quad->v1() - translation, quad->n1(), quad->t1(), false);
+					count += fragment->add_vertex(quad->v2() - translation, quad->n2(), quad->t2(), false);
+					count += fragment->add_vertex(quad->v3() - translation, quad->n3(), quad->t3(), false);
 					if (count == 4) {
 						model->model_quad_count++;
 					}
@@ -1118,10 +1186,10 @@ void MapFile::load_fragmentgroup(Model *model, const FragmentGroup::Type class_t
 				Quad *quad = (*quad_it);
 				if (quad->detail()) {
 					size_t count = 0;
-					count += fragment->add_vertex(quad->v0() - translation, quad->normal(), quad->t0(), false);
-					count += fragment->add_vertex(quad->v1() - translation, quad->normal(), quad->t1(), false);
-					count += fragment->add_vertex(quad->v2() - translation, quad->normal(), quad->t2(), false);
-					count += fragment->add_vertex(quad->v3() - translation, quad->normal(), quad->t3(), false);
+					count += fragment->add_vertex(quad->v0() - translation, quad->n0(), quad->t0(), true);
+					count += fragment->add_vertex(quad->v1() - translation, quad->n1(), quad->t1(), true);
+					count += fragment->add_vertex(quad->v2() - translation, quad->n2(), quad->t2(), true);
+					count += fragment->add_vertex(quad->v3() - translation, quad->n3(), quad->t3(), true);
 					if (count == 4) {
 						model->model_quad_count++;
 						model->model_quad_detail_count++;
diff --git a/src/model/quad.cc b/src/model/quad.cc
index 0830fe7..29aff34 100644
--- a/src/model/quad.cc
+++ b/src/model/quad.cc
@@ -17,8 +17,7 @@ Quad::Quad(const math::Vector3f &v0, const  math::Vector3f &v1, const math::Vect
 		quad_v2(v2),
 		quad_n2(normal),
 		quad_v3(v3),
-		quad_n3(normal),
-		quad_normal(normal)
+		quad_n3(normal)
 {
 	quad_detail = detail;
 }
diff --git a/src/model/quad.h b/src/model/quad.h
index b7dd7af..4609cea 100644
--- a/src/model/quad.h
+++ b/src/model/quad.h
@@ -90,11 +90,6 @@ public:
 		return quad_detail;
 	}
 
-	/// face normal
-	inline math::Vector3f &normal() {
-		return quad_normal;
-	}
-
 private:
 
 	math::Vector3f 		quad_v0;
@@ -113,7 +108,6 @@ private:
 	math::Vector3f 		quad_n3;
 	math::Vector2f		quad_t3;
 
-	math::Vector3f 		quad_normal;
 	bool			quad_detail;
 };