diff --git a/src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java b/src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java
index cb42d9f..0562944 100644
--- a/src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java
+++ b/src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java
@@ -74,6 +74,33 @@ public class RayTracerSimple extends RayTracer {
 			Color lightReflected = sample(Ray.pd(p, r), depthRemaining - 1);
 			result = result.add(material.reflective().mul(lightReflected));
 		}
+
+
+		if (material.refractive().notZero()) {
+			Vec3 b; // refracted light vector
+			double rInd = 1/material.refractiveIndex();
+
+			double iCosN = i.dot(n_);
+			if (iCosN < 0) {
+				rInd = 1/rInd;
+			}
+			Vec3 iProjection = n_.mul(iCosN);
+			Vec3 iRejection = i.sub(iProjection);
+			double iSinSqr = iRejection.lengthSquared()/i.lengthSquared();
+			double bSinSqr = iSinSqr*rInd*rInd;
+			if (bSinSqr > 1) {
+				b = r;
+			} else {
+				Vec3 bRejection = iRejection.inverse();
+				Vec3 bProjection = n_.mul(Math.sqrt(bRejection.lengthSquared()*(1-bSinSqr)/bSinSqr));
+				if (iCosN > 0) {
+					bProjection = bProjection.inverse();
+				}
+				b = bRejection.add(bProjection);
+			}
+			Color lightRefracted = sample(Ray.pd(p, b), depthRemaining - 1);
+			result = result.add(material.refractive().mul(lightRefracted));
+		}
 		
 		return result;
 	}
diff --git a/src/xyz/marsavic/gfxlab/playground/GfxLab.java b/src/xyz/marsavic/gfxlab/playground/GfxLab.java
index f09a15f..e8c9b56 100644
--- a/src/xyz/marsavic/gfxlab/playground/GfxLab.java
+++ b/src/xyz/marsavic/gfxlab/playground/GfxLab.java
@@ -8,7 +8,7 @@ import xyz.marsavic.gfxlab.graphics3d.Affine;
 import xyz.marsavic.gfxlab.graphics3d.cameras.Perspective;
 import xyz.marsavic.gfxlab.graphics3d.cameras.TransformedCamera;
 import xyz.marsavic.gfxlab.graphics3d.raytracers.RayTracerSimple;
-import xyz.marsavic.gfxlab.graphics3d.scene.DiscoRoom;
+import xyz.marsavic.gfxlab.graphics3d.scene.RefractionTest;
 import xyz.marsavic.gfxlab.gui.UtilsGL;
 import xyz.marsavic.gfxlab.tonemapping.ColorTransform;
 import xyz.marsavic.gfxlab.tonemapping.ToneMapping;
@@ -34,10 +34,12 @@ public class GfxLab {
 //												e(Blobs::new, val(5), val(0.1), val(0.2)),
 												e(RayTracerSimple::new,
 //														e(RefractionTest::new),
-														e(DiscoRoom::new, val(16), val(16), val(0x3361EB272FEA4C62L)),
+//														e(DiscoRoom::new, val(16), val(16), val(0x3361EB272FEA4C62L)),
+														e(RefractionTest::new),
 //														e(Mirrors::new, val(3)),
 														e(TransformedCamera::new,
 															e(Perspective::new, val(1.0/3)),
+//															e(Orthographic::new),
 															e(Affine.IDENTITY
 																	.then(Affine.translation(Vec3.xyz(0, 0, -4)))
 //																	.then(Affine.rotationAboutY(0.03))