diff --git a/core/Integrator.cpp b/core/Integrator.cpp
index d183b0db..e4559773 100644
--- a/core/Integrator.cpp
+++ b/core/Integrator.cpp
@@ -198,7 +198,7 @@ Spectrum VolumetricPathTracing::SolvingIntegrator(Ray& ray, IntersectionInfo& in
 	return radiance;
 }
 
-void VolumetricPathTracing::RenderImage(const PostProcessing& post, Spectrum* image) {
+void VolumetricPathTracing::RenderImage(const PostProcessing& post, RGBSpectrum* image) {
 	omp_set_num_threads(32);
 #pragma omp parallel for
 	for (int j = 0; j < height; j++) {
diff --git a/core/Integrator.h b/core/Integrator.h
index 5a51b71c..5cf2672f 100644
--- a/core/Integrator.h
+++ b/core/Integrator.h
@@ -27,7 +27,7 @@ class Integrator {
 
 	virtual Spectrum SolvingIntegrator(Ray& ray, IntersectionInfo& info) = 0;
 
-	virtual void RenderImage(const PostProcessing& post, Spectrum* image) = 0;
+	virtual void RenderImage(const PostProcessing& post, RGBSpectrum* image) = 0;
 
 protected:
 	IntegratorType m_type;
@@ -44,7 +44,7 @@ class VolumetricPathTracing : public Integrator {
 
 	virtual Spectrum SolvingIntegrator(Ray& ray, IntersectionInfo& info) override;
 
-	virtual void RenderImage(const PostProcessing& post, Spectrum* image) override;
+	virtual void RenderImage(const PostProcessing& post, RGBSpectrum* image) override;
 
 private:
 	int maxBounce;
diff --git a/core/Renderer.cpp b/core/Renderer.cpp
index e16a10ce..81b481e2 100644
--- a/core/Renderer.cpp
+++ b/core/Renderer.cpp
@@ -76,7 +76,7 @@ Renderer::~Renderer() {
 }
 
 void Renderer::Run() {
-	Spectrum* nowTexture = new Spectrum[width * height];
+	RGBSpectrum* nowTexture = new RGBSpectrum[width * height];
 	nowFrame = GetTextureRGB32F(width, height);
 
 	while (!glfwWindowShouldClose(window)) {
diff --git a/core/Spectrum.h b/core/Spectrum.h
index 192993c5..29a583f8 100644
--- a/core/Spectrum.h
+++ b/core/Spectrum.h
@@ -563,6 +563,12 @@ inline CoefficientSpectrum<nSpectrumSamples> Pow(
 	return ret;
 }
 
+inline float Luminance(const SampledSpectrum& color) {
+	RGBSpectrum rgb_color = color.ToRGBSpectrum();
+
+	return 0.299f * rgb_color[0] + 0.587f * rgb_color[1] + 0.114f * rgb_color[2];
+}
+
 inline float Luminance(const RGBSpectrum& color) {
 	return 0.299f * color[0] + 0.587f * color[1] + 0.114f * color[2];
 }
diff --git a/core/Utils.h b/core/Utils.h
index 2c3619fb..a0ac582f 100644
--- a/core/Utils.h
+++ b/core/Utils.h
@@ -34,7 +34,7 @@ template <int nSpectrumSamples>
 class CoefficientSpectrum;
 class RGBSpectrum;// Now only use rgb
 class SampledSpectrum;
-typedef RGBSpectrum Spectrum;
+typedef SampledSpectrum Spectrum;
 
 class ToneMapper;
 class Reinhard;
diff --git a/main.cpp b/main.cpp
index d0ddc70d..306a9d14 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,6 +1,8 @@
 #include "Renderer.h"
 
 int main() {
+	SampledSpectrum::Init();
+
 	int Width = 800;
 	int Height = 800;
 
@@ -13,7 +15,7 @@ int main() {
 	float sigma_s2[3] = { 0.5f, 0.75f, 0.25f };
 	float scale2 = 1.0f;
 	auto medium2 = std::make_shared<Homogeneous>(std::make_shared<Isotropic>(), Spectrum::FromRGB(sigma_s2), Spectrum::FromRGB(sigma_a2), scale2);
-
+	//medium2 = NULL;
 	medium = NULL;
 	//std::shared_ptr<Medium> medium = NULL;
 	//Transform tran = Transform::Rotate(0.0f, 45.0f, 0.0f);