Add normals implementation

.gitignore

@@ -24,4 +24,7 @@ rules.ninja
 *.dir
 *.opendb
 Debug
-x64
+x64
+
+*.exr
+*.png

CMakeLists.txt

@@ -88,6 +88,7 @@ add_executable(nori
   src/microfacet.cpp
   src/mirror.cpp
   src/dielectric.cpp
+  src/normals.cpp
 )
 
 add_definitions(${NANOGUI_EXTRA_DEFS})

src/normals.cpp

@@ -0,0 +1,30 @@
+#include <nori/integrator.h>
+#include <nori/scene.h>
+
+NORI_NAMESPACE_BEGIN
+
+class NormalIntegrator : public Integrator {
+public:
+    NormalIntegrator(const PropertyList &props) {
+        /* No parameters this time */
+    }
+
+    Color3f Li(const Scene *scene, Sampler *sampler, const Ray3f &ray) const {
+        /* Find the surface that is visible in the requested direction */
+        Intersection its;
+        if (!scene->rayIntersect(ray, its))
+            return Color3f(0.0f);
+
+        /* Return the component-wise absolute
+           value of the shading normal as a color */
+        Normal3f n = its.shFrame.n.cwiseAbs();
+        return Color3f(n.x(), n.y(), n.z());
+    }
+
+    std::string toString() const {
+        return "NormalIntegrator[]";
+    }
+};
+
+NORI_REGISTER_CLASS(NormalIntegrator, "normals");
+NORI_NAMESPACE_END