rough plastic documentation is done..

src/bsdfs/roughplastic.cpp

@@ -86,7 +86,6 @@ MTS_NAMESPACE_BEGIN
  *     \rendering{GGX, $\alpha=0.3$}{bsdf_roughplastic_ggx}
  * }
  *
- *
  * This plugin is essentially the ``roughened'' equivalent of the (smooth) plugin
  * \pluginref{plastic}. For very low values of $\alpha$, the two will
  * be identical, though scenes using this plugin will take longer to render 
@@ -108,8 +107,8 @@ MTS_NAMESPACE_BEGIN
  *
  * The simplicity of this setup makes it possible to account for interesting
  * nonlinear effects due to internal scattering, which is controlled by
- * the \texttt{nonlinear} parameter. Please refer to the description of this
- * parameter given in the the \pluginref{plastic} plugin section 
+ * the \texttt{nonlinear} parameter. For more details, please refer to the description 
+ * of this parameter given in the the \pluginref{plastic} plugin section 
  * on \pluginpage{plastic}.
  *
  *
@@ -136,18 +135,30 @@ MTS_NAMESPACE_BEGIN
  * }
  * \newpage
  * \renderings{
- *     \setcounter{subfigure}{2}
- *     \rendering{Beckmann, $\alpha=0.05$, diffuseReflectance=0}
- *         {bsdf_roughplastic_beckmann_lacquer}
+ *     \rendering{Wood material with smooth horizontal stripes}{bsdf_roughplastic_roughtex1}
+ *     \rendering{A material with imperfections at a much smaller scale than what 
+ *       is modeled e.g. using a bump map.}{bsdf_roughplastic_roughtex2}\vspace{-3mm}
+ *     \caption{
+ *         The ability to texture the roughness parameter makes it possible
+ *         to render materials with a structured finish, as well as 
+ *         ``smudgy'' objects.
+ *     }
  * }
- *
- * \begin{xml}[caption={A material definition for rough, black laquer.}, 
- *    label=lst:roughplastic-lacquer]
+ * \vspace{2mm}
+ * \begin{xml}[caption={A material definition for black plastic material with
+ *    a spatially varying roughness.}, 
+ *    label=lst:roughplastic-varyingalpha]
  * <bsdf type="roughplastic">
  *     <string name="distribution" value="beckmann"/>
- *     <float name="alpha" value="0.05"/>
  *     <float name="intIOR" value="1.61"/>
  *     <spectrum name="diffuseReflectance" value="0"/>
+ *     <!-- Fetch roughness values from a texture and slightly reduce them -->
+ *     <texture type="scale" name="alpha">
+ *         <texture name="alpha" type="bitmap">
+ *             <string name="filename" value="bump.png"/>
+ *         </texture>
+ *         <float name="scale" value="0.6"/>
+ *     </texture>
  * </bsdf>
  * \end{xml}
  *
@@ -159,6 +170,17 @@ MTS_NAMESPACE_BEGIN
  * restricted here---in comparison to other rough scattering models in 
  * Mitsuba, anisotropic distributions are not allowed.
  *
+ * The implementation of this model makes heavy use of a \emph{rough
+ * Fresnel transmittance} function, which is a generalization of the 
+ * usual Fresnel transmittion coefficient to microfacet surfaces. Unfortunately,
+ * this function is normally prohibitively expensive, since each 
+ * evaluation involves a numerical integration over the sphere. 
+ *
+ * To avoid this performance issue, Mitsuba ships with data files
+ * (contained in the \code{data/microfacet} directory) containing precomputed 
+ * values of this function over a large range of parameter values. At runtime,
+ * the relevant parts are extracted using tricubic interpolation.
+ *
  * When rendering with the Phong microfacet distributions, a conversion 
  * is used to turn the specified $\alpha$ roughness value into the Phong 
  * exponent. This is done in a way, such that the different distributions 

src/shapes/obj.cpp

@@ -47,11 +47,12 @@ MTS_NAMESPACE_BEGIN
  *        Note that non-uniform scales are not permitted!
  *        \default{none (i.e. object space $=$ world space)}
  *     }
- *     \parameter{recenter}{\Boolean}{
- *       When set to \code{true}, the geometry will be uniformly scaled 
- *       and shifted to so that its object-space footprint fits into $[-1, 1]^3$.
- *	   }
  * }
+ *
+ * This plugin implements a simple loader for Wavefront OBJ files. It handles
+ * triangle and quad meshes, vertex normals, and UV coordinates. Due to the
+ * heavy-weight nature of OBJ files, this loader is usually quite a bit slower
+ * than the \pluginref{ply} or \pluginref{serialized} plugins.
  */
 class WavefrontOBJ : public Shape {
 public:
@@ -103,10 +104,6 @@ public:
 		*/
 		m_faceNormals = props.getBoolean("faceNormals", false);
 
-		/* Re-center & scale all contents to move them into the 
-		   AABB [-1, -1, -1]x[1, 1, 1]? */
-		m_recenter = props.getBoolean("recenter", false);
-
 		/* Causes all normals to be flipped */
 		m_flipNormals = props.getBoolean("flipNormals", false);
 
@@ -360,20 +357,6 @@ public:
 		std::map<Vertex, int, vertex_key_order> vertexMap;
 		std::vector<Vertex> vertexBuffer;
 		size_t numMerged = 0;
-		Vector translate(0.0f);
-		Float scale = 0.0f;
-
-		if (m_recenter) {
-			AABB aabb;
-			for (unsigned int i=0; i<triangles.size(); i++) {
-				for (unsigned int j=0; j<3; j++) {
-					unsigned int vertexId = triangles[i].p[j];
-					aabb.expandBy(vertices.at(vertexId));
-				}
-			}
-			scale = 2/aabb.getExtents()[aabb.getLargestAxis()];
-			translate = -Vector(aabb.getCenter());
-		}
 
 		/* Collapse the mesh into a more usable form */
 		Triangle *triangleArray = new Triangle[triangles.size()];
@@ -387,10 +370,7 @@ public:
 
 				Vertex vertex;
 
-				if (m_recenter)
-					vertex.p = objectToWorld((vertices.at(vertexId) + translate)*scale);
-				else
-					vertex.p = objectToWorld(vertices.at(vertexId));
+				vertex.p = objectToWorld(vertices.at(vertexId));
 
 				if (hasNormals && normalId >= 0 && normals.at(normalId) != Normal(0.0f))
 					vertex.n = normalize(objectToWorld(normals.at(normalId)));
@@ -533,7 +513,7 @@ public:
 private:
 	std::vector<TriMesh *> m_meshes;
 	std::map<std::string, BSDF *> m_materials;
-	bool m_flipNormals, m_faceNormals, m_recenter;
+	bool m_flipNormals, m_faceNormals;
 	std::string m_name;
 	AABB m_aabb;
 };

src/shapes/ply.cpp

@@ -67,8 +67,15 @@ MTS_NAMESPACE_BEGIN
  *     \rendering{The Stanford bunny loaded with \code{faceNormals=true}. Note
  *         the faceted appearance.}{shape_ply_bunny}
  * }
- * This plugin is based on the library \code{libply} by Ares Lagae
- * (\url{http://people.cs.kuleuven.be/~ares.lagae/libply}).
+ * This plugin implements a fast loader for the Stanford PLY format (both
+ * the ASCII and binary format). It is based on the \code{libply} library by 
+ * Ares Lagae (\url{http://people.cs.kuleuven.be/~ares.lagae/libply}).
+ * The current plugin implementation supports triangle meshes with optional
+ * UV coordinates, vertex normals, and vertex colors.
+ *
+ * When loading meshes that contain vertex colors, note that they need to be
+ * explicitly referenced in a BSDF using a special texture named
+ * \pluginref{vertexcolors}.
  */
 class PLYLoader : public TriMesh {
 public: