starting to work on a directional luminaire

ChangeLog

@@ -1,3 +1,10 @@
+2010-08-12  Wenzel Jakob <wenzel@cs.cornell.edu>
+
+	* converter.cpp: Much better import of COLLADA scenes from
+		blender.
+
+	* importdlg.cpp: User interface for importing scenes.
+
 2010-08-09  Wenzel Jakob <wenzel@cs.cornell.edu>
 
 	* rendersettingsdlg.cpp: Try to maintain the number of 

SConstruct

@@ -528,6 +528,7 @@ plugins += env.SharedLibrary('plugins/envmap', ['src/luminaires/envmap.cpp'])
 plugins += env.SharedLibrary('plugins/spot', ['src/luminaires/spot.cpp'])
 plugins += env.SharedLibrary('plugins/point', ['src/luminaires/point.cpp'])
 plugins += env.SharedLibrary('plugins/collimated', ['src/luminaires/collimated.cpp'])
+plugins += env.SharedLibrary('plugins/directional', ['src/luminaires/directional.cpp'])
 
 # Integrators
 plugins += env.SharedLibrary('plugins/direct', ['src/integrators/direct/direct.cpp'])

src/collada/converter.cpp

@@ -543,6 +543,18 @@ void loadLight(Transform transform, std::ostream &os, domLight &light) {
 		os << "\t\t</transform>" << endl;
 		os << "\t</luminaire>" << endl << endl;
 	}
+
+	domLight::domTechnique_common::domDirectional *directional = light.getTechnique_common()->getDirectional().cast();
+	if (directional) {
+		domFloat3 &color = directional->getColor()->getValue();
+		os << "\t<luminaire id=\"" << light.getId() << "\" type=\"directional\">" << endl;
+		os << "\t\t<rgb name=\"intensity\" value=\"" << color[0]*intensity << " " << color[1]*intensity << " " << color[2]*intensity << "\"/>" << endl << endl;
+		os << "\t\t<transform name=\"toWorld\">" << endl;
+		os << "\t\t\t<lookAt ox=\"" << pos.x << "\" oy=\"" << pos.y << "\" oz=\"" << pos.z << "\" tx=\"" << target.x << "\" ty=\"" << target.y << "\" tz=\"" << target.z << "\"/>" << endl;
+		os << "\t\t</transform>" << endl << endl;
+		os << "\t</luminaire>" << endl << endl;
+	}
+
 	domLight::domTechnique_common::domSpot *spot = light.getTechnique_common()->getSpot().cast();
 	if (spot) {
 		domFloat3 &color = spot->getColor()->getValue();
@@ -564,7 +576,7 @@ void loadLight(Transform transform, std::ostream &os, domLight &light) {
 		os << "\t\t<rgb name=\"intensity\" value=\"" << color[0]*intensity << " " << color[1]*intensity << " " << color[2]*intensity << "\"/>" << endl;
 		os << "\t</luminaire>" << endl << endl;
 	}
-	if (!point && !spot && !ambient)
+	if (!point && !spot && !ambient && !directional)
 		SLog(EWarn, "Encountered an unknown light type!");
 }
 

src/luminaires/directional.cpp

@@ -0,0 +1,135 @@
+#include <mitsuba/render/scene.h>
+
+MTS_NAMESPACE_BEGIN
+
+/**
+ * Simple directional luminaire
+ */
+class DirectionalLuminaire : public Luminaire {
+public:
+	DirectionalLuminaire(const Properties &props) : Luminaire(props) {
+		m_radius = props.getFloat("radius", 0.01f);
+		m_surfaceArea = m_radius * m_radius * M_PI;
+		Spectrum power = props.getSpectrum("power", 1);
+		m_intensity = props.getSpectrum("intensity", power / m_surfaceArea);
+		m_invSurfaceArea = 1 / m_surfaceArea;
+		m_direction = m_luminaireToWorld(Vector(0, 0, 1));
+		m_type = EDeltaDirection | EDeltaPosition;
+	}
+
+	DirectionalLuminaire(Stream *stream, InstanceManager *manager) 
+		: Luminaire(stream, manager) {
+		m_intensity = Spectrum(stream);
+		m_radius = stream->readFloat();
+		m_invSurfaceArea = 1 / m_surfaceArea;
+		m_direction = m_luminaireToWorld(Vector(0, 0, 1));
+	}
+
+	void serialize(Stream *stream, InstanceManager *manager) const {
+		Luminaire::serialize(stream, manager);
+		m_intensity.serialize(stream);
+		stream->writeFloat(m_radius);
+	}
+
+	Spectrum getPower() const {
+		return m_intensity * m_surfaceArea;
+	}
+
+	Spectrum Le(const LuminaireSamplingRecord &lRec) const {
+		/* Collimated beam is not part of the scene */
+		Log(EWarn, "This function should never be called.");
+		return Spectrum(0.0f);
+	}
+
+	inline Float pdf(const Point &p, const LuminaireSamplingRecord &lRec) const {
+		/* PDF is a delta function - zero probability when a sample point was not
+		   generated using sample() */
+		return 0.0f;
+	}
+
+	Float pdf(const Intersection &its, const LuminaireSamplingRecord &lRec) const {
+		return DirectionalLuminaire::pdf(its.p, lRec);
+	}
+
+	inline void sample(const Point &p, LuminaireSamplingRecord &lRec,
+		const Point2 &sample) const {
+		Point local = m_worldToLuminaire(p);
+		Vector2 planeProjection = Vector2(local.x, local.y);
+
+		if (planeProjection.length() > m_radius || local.z < 0) {
+			lRec.pdf = 0.0f;
+		} else {
+			lRec.sRec.p = m_luminaireToWorld(Point(local.x, local.y, 0));
+			lRec.d = m_direction;
+			lRec.luminaire = this;
+			lRec.pdf = 1.0f;
+			lRec.Le = m_intensity;
+		}
+	}
+
+	void sample(const Intersection &its, LuminaireSamplingRecord &lRec,
+		const Point2 &sample) const {
+		DirectionalLuminaire::sample(its.p, lRec, sample);
+	}
+
+	void sampleEmission(EmissionRecord &eRec, const Point2 &sample1, const Point2 &sample2) const {
+		Point2 posOnDisk = squareToDiskConcentric(sample1) * m_radius;
+		eRec.sRec.p = m_luminaireToWorld(Point(posOnDisk.x, posOnDisk.y, 0));
+		eRec.d = m_direction;
+		eRec.pdfArea = m_invSurfaceArea;
+		eRec.pdfDir = 1;
+		eRec.P = m_intensity;
+	}
+
+	void sampleEmissionArea(EmissionRecord &eRec, const Point2 &sample) const {
+		Point2 posOnDisk = squareToDiskConcentric(sample) * m_radius;
+		eRec.sRec.p = m_luminaireToWorld(Point(posOnDisk.x, posOnDisk.y, 0));
+		eRec.pdfArea = m_invSurfaceArea;
+		eRec.P = m_intensity;
+	}
+
+	Spectrum sampleEmissionDirection(EmissionRecord &eRec, const Point2 &sample) const {
+		eRec.d = m_direction;
+		eRec.pdfDir = 1;
+		return Spectrum(1.0f);
+	}
+
+	Spectrum fArea(const EmissionRecord &eRec) const {
+		return m_intensity;
+	}
+
+	Spectrum f(const EmissionRecord &eRec) const {
+		/* Collimated beam is not part of the scene */
+		Log(EWarn, "This function should never be called.");
+		return Spectrum(0.0f);
+	}
+
+	void pdfEmission(EmissionRecord &eRec) const {
+		eRec.pdfArea = m_invSurfaceArea;
+		eRec.pdfDir = 0;
+		eRec.P = m_intensity;
+	}
+
+	std::string toString() const {
+		std::ostringstream oss;
+		oss << "DirectionalLuminaire[" << std::endl
+			<< "  intensity = " << m_intensity.toString() << "," << std::endl
+			<< "  power = " << getPower().toString() << "," << std::endl
+			<< "  position = " << m_luminaireToWorld(Point(0, 0, 0)).toString() << "," << std::endl
+			<< "  direction = " << m_direction.toString() << "," << std::endl
+			<< "  radius = " << m_radius << std::endl
+			<< "]";
+		return oss.str();
+	}
+
+	MTS_DECLARE_CLASS()
+private:
+	Spectrum m_intensity;
+	Vector m_direction;
+	Float m_invSurfaceArea;
+	Float m_radius;
+};
+
+MTS_IMPLEMENT_CLASS_S(DirectionalLuminaire, false, Luminaire)
+MTS_EXPORT_PLUGIN(DirectionalLuminaire, "Directional luminaire");
+MTS_NAMESPACE_END