added a cube shape, relaxed some of the requirements regarding uniform scales

src/shapes/CMakeLists.txt

@@ -15,6 +15,7 @@ add_shape(rectangle  rectangle.cpp)
 add_shape(disk       disk.cpp)
 add_shape(sphere     sphere.cpp)
 add_shape(cylinder   cylinder.cpp)
+add_shape(cube       cube.cpp)
 add_shape(hair       hair.h hair.cpp)
 add_shape(shapegroup shapegroup.h shapegroup.cpp)
 add_shape(instance   instance.h instance.cpp)

src/shapes/SConscript

@@ -11,6 +11,7 @@ plugins += env.SharedLibrary('cylinder', ['cylinder.cpp'])
 plugins += env.SharedLibrary('hair', ['hair.cpp'])
 plugins += env.SharedLibrary('shapegroup', ['shapegroup.cpp'])
 plugins += env.SharedLibrary('instance', ['instance.cpp'])
+plugins += env.SharedLibrary('cube', ['cube.cpp'])
 #plugins += env.SharedLibrary('deformable', ['deformable.cpp'])
 
 Export('plugins')

src/shapes/cube.cpp

@@ -0,0 +1,115 @@
+/*
+    This file is part of Mitsuba, a physically based rendering system.
+
+    Copyright (c) 2007-2012 by Wenzel Jakob and others.
+
+    Mitsuba is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License Version 3
+    as published by the Free Software Foundation.
+
+    Mitsuba is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <mitsuba/render/trimesh.h>
+#include <mitsuba/core/properties.h>
+
+MTS_NAMESPACE_BEGIN
+
+static Float CubeData_vertexPositions[][3] = {{1, 0, 0}, {1, 0, 1}, {0, 0, 1}, {0, 0, 0}, {1, 1, 0}, {0, 1, 0}, {0, 1, 1}, {1, 1, 1}, {1, 0, 0}, {1, 1, 0}, {1, 1, 1}, {1, 0, 1}, {1, 0, 1}, {1, 1, 1}, {0, 1, 1}, {0, 0, 1}, {0, 0, 1}, {0, 1, 1}, {0, 1, 0}, {0, 0, 0}, {1, 1, 0}, {1, 0, 0}, {0, 0, 0}, {0, 1, 0}};
+
+static Float CubeData_vertexNormals[][3] = {{0, -1, 0}, {0, -1, 0}, {0, -1, 0}, {0, -1, 0}, {0, 1, 0}, {0, 1, 0}, {0, 1, 0}, {0, 1, 0}, {1, 0, 0}, {1, 0, 0}, {1, 0, 0}, {1, 0, 0}, {0, 0, 1}, {0, 0, 1}, {0, 0, 1}, {0, 0, 1}, {-1, 0, 0}, {-1, 0, 0}, {-1, 0, 0}, {-1, 0, 0}, {0, 0, -1}, {0, 0, -1}, {0, 0, -1}, {0, 0, -1}};
+
+static Float CubeData_texcoords[][2] = {{0, 1}, {1, 1}, {1, 0}, {0, 0}, {0, 1}, {1, 1}, {1, 0}, {0, 0}, {0, 1}, {1, 1}, {1, 0}, {0, 0}, {0, 1}, {1, 1}, {1, 0}, {0, 0}, {0, 1}, {1, 1}, {1, 0}, {0, 0}, {0, 1}, {1, 1}, {1, 0}, {0, 0}};
+
+static uint32_t CubeData_triangles[][3] = {{0, 1, 2}, {3, 0, 2}, {4, 5, 6}, {7, 4, 6}, {8, 9, 10}, {11, 8, 10}, {12, 13, 14}, {15, 12, 14}, {16, 17, 18}, {19, 16, 18}, {20, 21, 22}, {23, 20, 22}};
+
+/*!\plugin{cube}{Cube intersection primitive}
+ * \order{0}
+ * \parameters{
+ *     \parameter{toWorld}{\Transform\Or\Animation}{
+ *	      Specifies an optional linear object-to-world transformation.
+ *        \default{none (i.e. object space $=$ world space)}
+ *     }
+ *     \parameter{flipNormals}{\Boolean}{
+ *	      Is the cube inverted, i.e. should the normal vectors
+ *		  be flipped? \default{\code{false}, i.e. the normals point outside}
+ *	   }
+ * }
+ *
+ * \renderings{
+ *     \rendering{Basic example, see \lstref{cube-basic}}
+ *         {shape_cube_basic}
+ *     \rendering{A textured and stretched cube with the default parameterization
+ *      (Listing~\ref{lst:cube-example})}
+ *         {shape_cube_parameterization}
+ * }
+ *
+ * This shape plugin describes a simple cube/cuboid intersection primitive. By
+ * default, it creates a cube between the world-space positions $(0, 0, 0)$ and $(1,1,1)$.
+ * However, an arbitrary linear transformation may be specified to translate, rotate, scale
+ * or skew it as desired. The parameterization of this shape maps every face onto the
+ * rectangle $[0,1]^2$ in $uv$ space.
+ * \vspace{5mm}
+ * \begin{xml}[caption={Example of a textured and stretched cube}, label=lst:cube-example]
+ * <shape type="cube">
+ *   <transform name="toWorld">
+ *     <scale z="2"/>
+ *   </transform>
+ *
+ *   <bsdf type="diffuse">
+ *     <texture type="checkerboard" name="reflectance">
+ *       <float name="uvscale" value="6"/>
+ *     </texture>
+ *   </bsdf>
+ * </shape>
+ * \end{xml}
+ */
+class Cube : public TriMesh {
+public:
+	Cube(const Properties &props) : TriMesh(props) {
+		m_name = props.getID();
+		m_triangleCount = 12;
+		m_vertexCount = 24;
+		m_positions = new Point[m_vertexCount];
+		m_texcoords = new Point2[m_vertexCount];
+		m_normals = new Normal[m_vertexCount];
+		m_triangles = new Triangle[m_triangleCount];
+
+		Transform toWorld = props.getTransform("toWorld", Transform());
+		for (uint32_t i=0; i<m_vertexCount; ++i) {
+			Normal n;
+			Point p;
+			Point2 uv;
+
+			for (int j=0; j<3; ++j) {
+				p[j] = CubeData_vertexPositions[i][j];
+				n[j] = CubeData_vertexNormals[i][j];
+			}
+			for (int j=0; j<2; ++j)
+				uv[j] = CubeData_texcoords[i][j];
+
+			m_positions[i] = toWorld(p);
+			m_normals[i] = normalize(toWorld(n));
+			m_texcoords[i] = uv;
+		}
+
+		for (uint32_t i=0; i<m_triangleCount; ++i)
+			for (int j=0; j<3; ++j)
+				m_triangles[i].idx[j] = CubeData_triangles[i][j];
+	}
+
+	Cube(Stream *stream, InstanceManager *manager)
+		: TriMesh(stream, manager) { }
+
+	MTS_DECLARE_CLASS()
+};
+
+MTS_IMPLEMENT_CLASS_S(Cube, false, TriMesh)
+MTS_EXPORT_PLUGIN(Cube, "Cube intersection primitive");
+MTS_NAMESPACE_END

src/shapes/obj.cpp

@@ -57,7 +57,6 @@ MTS_NAMESPACE_BEGIN
  *	   }
  *     \parameter{toWorld}{\Transform\Or\Animation}{
  *	      Specifies an optional linear object-to-world transformation.
- *        Note that non-uniform scales are not permitted!
  *        \default{none (i.e. object space $=$ world space)}
  *     }
  * }

src/shapes/ply.cpp

@@ -64,7 +64,6 @@ MTS_NAMESPACE_BEGIN
  *	   }
  *     \parameter{toWorld}{\Transform\Or\Animation}{
  *	      Specifies an optional linear object-to-world transformation.
- *        Note that non-uniform scales are not permitted!
  *        \default{none (i.e. object space $=$ world space)}
  *     }
  *     \parameter{srgb}{\Boolean}{
@@ -230,7 +229,7 @@ public:
 		m_aabb.expandBy(p);
 		m_positions[m_vertexCtr] = p;
 		if (m_normals)
-			m_normals[m_vertexCtr] = m_objectToWorld(m_normal);
+			m_normals[m_vertexCtr] = normalize(m_objectToWorld(m_normal));
 		if (m_texcoords)
 			m_texcoords[m_vertexCtr] = m_uv;
 		if (m_colors) {

src/shapes/serialized.cpp

@@ -57,7 +57,6 @@ MTS_NAMESPACE_BEGIN
  *	   }
  *     \parameter{toWorld}{\Transform\Or\Animation}{
  *	      Specifies an optional linear object-to-world transformation.
- *        Note that non-uniform scales are not permitted!
  *        \default{none (i.e. object space $=$ world space)}
  *     }
  * }
@@ -185,7 +184,7 @@ public:
 			}
 			if (m_normals) {
 				for (size_t i=0; i<m_vertexCount; ++i)
-					m_normals[i] = objectToWorld(m_normals[i]);
+					m_normals[i] = normalize(objectToWorld(m_normals[i]));
 			}
 		}