diff --git a/configure.py b/configure.py
index f06f5a5f..7b69047a 100755
--- a/configure.py
+++ b/configure.py
@@ -28,6 +28,7 @@ COMPLETE_OBJECTS = [
     "MetroidPrime/HUD/CHUDMemoParms",
     "MetroidPrime/ScriptObjects/CScriptDebugCameraWaypoint",
     "Weapons/IWeaponRenderer",
+    "Collision/CMRay",
     "Kyoto/Basics/CStopwatch",
     "Kyoto/Basics/COsContextDolphin",
     "Kyoto/Basics/CSWDataDolphin",
diff --git a/include/Collision/CMRay.hpp b/include/Collision/CMRay.hpp
new file mode 100644
index 00000000..cf252c7b
--- /dev/null
+++ b/include/Collision/CMRay.hpp
@@ -0,0 +1,22 @@
+#ifndef __CMRAY_HPP__
+#define __CMRAY_HPP__
+
+#include "Kyoto/Math/CVector3f.hpp"
+
+class CTransform4f;
+class CMRay {
+public:
+  CMRay(const CVector3f& start, const CVector3f& end, float, float);
+  CMRay(const CVector3f& start, const CVector3f& end, float);
+  CMRay GetInvUnscaledTransformRay(const CTransform4f&) const;
+
+private:
+  CVector3f mStart;
+  CVector3f mEnd;
+  CVector3f mDelta;
+  float mLength;
+  float mInvLength;
+  CVector3f mDir;
+};
+
+#endif // __CMRAY_HPP__
diff --git a/obj_files.mk b/obj_files.mk
index 5caff98a..fd9bedb6 100644
--- a/obj_files.mk
+++ b/obj_files.mk
@@ -415,7 +415,7 @@ COLLISION :=\
 	$(BUILD_DIR)/asm/Collision/CCollidableSphere.o\
 	$(BUILD_DIR)/asm/Collision/CMaterialFilter.o\
 	$(BUILD_DIR)/asm/Collision/COBBox.o\
-	$(BUILD_DIR)/asm/Collision/CMRay.o\
+	$(BUILD_DIR)/src/Collision/CMRay.o\
 
 KYOTO_1 :=\
 	$(BUILD_DIR)/asm/Kyoto/Basics/CBasics.o\
diff --git a/src/Collision/CMRay.cpp b/src/Collision/CMRay.cpp
new file mode 100644
index 00000000..3eb97a7e
--- /dev/null
+++ b/src/Collision/CMRay.cpp
@@ -0,0 +1,25 @@
+#include "Collision/CMRay.hpp"
+#include "Kyoto/Math/CTransform4f.hpp"
+
+CMRay::CMRay(const CVector3f& start, const CVector3f& end, float length, float invLength)
+: mStart(start)
+, mEnd(end)
+, mDelta(mEnd - mStart)
+, mLength(length)
+, mInvLength(invLength)
+, mDir(mInvLength * mDelta)  {  
+}
+
+CMRay::CMRay(const CVector3f& start, const CVector3f& dir, float length)
+: mStart(start)
+, mEnd(start + length * dir)
+, mDelta(mEnd - mStart)
+, mLength(length)
+, mInvLength(1.f / length)
+, mDir(dir) {}
+
+
+CMRay CMRay::GetInvUnscaledTransformRay(const CTransform4f& xf) const {
+  CTransform4f invXf = xf.GetQuickInverse();
+  return CMRay(invXf * mStart, invXf * mEnd, mLength, mInvLength);
+}