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diff --git a/src/gleem/linalg/PlaneUV.java b/src/gleem/linalg/PlaneUV.java
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+/*
+ * gleem -- OpenGL Extremely Easy-To-Use Manipulators.
+ * Copyright (C) 1998-2003 Kenneth B. Russell ([email protected])
+ *
+ * Copying, distribution and use of this software in source and binary
+ * forms, with or without modification, is permitted provided that the
+ * following conditions are met:
+ *
+ * Distributions of source code must reproduce the copyright notice,
+ * this list of conditions and the following disclaimer in the source
+ * code header files; and Distributions of binary code must reproduce
+ * the copyright notice, this list of conditions and the following
+ * disclaimer in the documentation, Read me file, license file and/or
+ * other materials provided with the software distribution.
+ *
+ * The names of Sun Microsystems, Inc. ("Sun") and/or the copyright
+ * holder may not be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS," WITHOUT A WARRANTY OF ANY
+ * KIND. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
+ * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, NON-INTERFERENCE, ACCURACY OF
+ * INFORMATIONAL CONTENT OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. THE
+ * COPYRIGHT HOLDER, SUN AND SUN'S LICENSORS SHALL NOT BE LIABLE FOR
+ * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
+ * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL THE
+ * COPYRIGHT HOLDER, SUN OR SUN'S LICENSORS BE LIABLE FOR ANY LOST
+ * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
+ * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
+ * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
+ * INABILITY TO USE THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGES. YOU ACKNOWLEDGE THAT THIS SOFTWARE IS NOT
+ * DESIGNED, LICENSED OR INTENDED FOR USE IN THE DESIGN, CONSTRUCTION,
+ * OPERATION OR MAINTENANCE OF ANY NUCLEAR FACILITY. THE COPYRIGHT
+ * HOLDER, SUN AND SUN'S LICENSORS DISCLAIM ANY EXPRESS OR IMPLIED
+ * WARRANTY OF FITNESS FOR SUCH USES.
+ */
+
+package gleem.linalg;
+
+/** This differs from the Plane class in that it maintains an origin
+    and orthonormal U, V axes in the plane so that it can project a 3D
+    point to a 2D one. U cross V = normal. U and V coordinates are
+    computed with respect to the origin. */
+
+public class PlaneUV {
+  private Vec3f origin = new Vec3f();
+  /** Normalized */
+  private Vec3f normal = new Vec3f();
+  private Vec3f uAxis  = new Vec3f();
+  private Vec3f vAxis  = new Vec3f();
+
+  /** Default constructor initializes normal to (0, 1, 0), origin to
+      (0, 0, 0), U axis to (1, 0, 0) and V axis to (0, 0, -1). */
+  public PlaneUV() {
+    setEverything(new Vec3f(0, 1, 0),
+                  new Vec3f(0, 0, 0),
+                  new Vec3f(1, 0, 0),
+                  new Vec3f(0, 0, -1));
+  }
+
+  /** Takes normal vector and a point which the plane goes through
+      (which becomes the plane's "origin"). Normal does NOT have to be
+      normalized, but may not be zero vector. U and V axes are
+      initialized to arbitrary values. */
+  public PlaneUV(Vec3f normal, Vec3f origin) {
+    setOrigin(origin);
+    setNormal(normal);
+  }
+
+  /** Takes normal vector, point which plane goes through, and the "u"
+    axis in the plane. Computes the "v" axis by taking the cross
+    product of the normal and the u axis. Axis must be perpendicular
+    to normal. Normal and uAxis do NOT have to be normalized, but
+    neither may be the zero vector. */
+  public PlaneUV(Vec3f normal,
+                 Vec3f origin,
+                 Vec3f uAxis) {
+    setOrigin(origin);
+    setNormalAndU(normal, uAxis);
+  }
+
+  /** Takes normal vector, point which plane goes through, and both
+    the u and v axes. u axis cross v axis = normal. Normal, uAxis, and
+    vAxis do NOT have to be normalized, but none may be the zero
+    vector. */
+  public PlaneUV(Vec3f normal,
+                 Vec3f origin,
+                 Vec3f uAxis,
+                 Vec3f vAxis) {
+    setEverything(normal, origin, uAxis, vAxis);
+  }
+
+  /** Set the origin, through which this plane goes and with respect
+      to which U and V coordinates are computed */
+  public void setOrigin(Vec3f origin) {
+    this.origin.set(origin);
+  }
+
+  public Vec3f getOrigin() {
+    return new Vec3f(origin);
+  }
+
+  /** Normal, U and V axes must be orthogonal and satisfy U cross V =
+      normal, do not need to be unit length but must not be the zero
+      vector. */
+  public void setNormalAndUV(Vec3f normal,
+                             Vec3f uAxis,
+                             Vec3f vAxis) {
+    setEverything(normal, origin, uAxis, vAxis);
+  }
+
+  /** This version sets the normal vector and generates new U and V
+      axes. */
+  public void setNormal(Vec3f normal) {
+    Vec3f uAxis = new Vec3f();
+    MathUtil.makePerpendicular(normal, uAxis);
+    Vec3f vAxis = normal.cross(uAxis);
+    setEverything(normal, origin, uAxis, vAxis);
+  }
+
+  /** This version computes the V axis from (normal cross U). */
+  public void setNormalAndU(Vec3f normal,
+                            Vec3f uAxis) {
+    Vec3f vAxis = normal.cross(uAxis);
+    setEverything(normal, origin, uAxis, vAxis);
+  }
+
+  /** Normal, U and V axes are normalized internally, so, for example,
+      <b>normal</b> is not necessarily equal to
+      <code>plane.setNormal(normal); plane.getNormal();</code> */
+  public Vec3f getNormal() {
+    return normal;
+  }
+
+  public Vec3f getUAxis() {
+    return uAxis;
+  }
+
+  public Vec3f getVAxis() {
+    return vAxis;
+  }
+
+  /** Project a point onto the plane */
+  public void projectPoint(Vec3f point,
+                           Vec3f projPt,
+                           Vec2f uvCoords) {
+    // Using projPt as a temporary
+    projPt.sub(point, origin);
+    float dotp = normal.dot(projPt);
+    // Component perpendicular to plane
+    Vec3f tmpDir = new Vec3f();
+    tmpDir.set(normal);
+    tmpDir.scale(dotp);
+    projPt.sub(projPt, tmpDir);
+    // Take dot products with basis vectors
+    uvCoords.set(projPt.dot(uAxis),
+                 projPt.dot(vAxis));
+    // Add on center to intersection point
+    projPt.add(origin);
+  }
+
+  /** Intersect a ray with this plane, outputting not only the 3D
+      intersection point but also the U, V coordinates of the
+      intersection. Returns true if intersection occurred, false
+      otherwise. This is a two-sided ray cast. */
+  public boolean intersectRay(Vec3f rayStart,
+                              Vec3f rayDirection,
+                              IntersectionPoint intPt,
+                              Vec2f uvCoords) {
+    float denom = rayDirection.dot(normal);
+    if (denom == 0.0f)
+      return false;
+    Vec3f tmpDir = new Vec3f();
+    tmpDir.sub(origin, rayStart);
+    float t = tmpDir.dot(normal) / denom;
+    // Find intersection point
+    Vec3f tmpPt = new Vec3f();
+    tmpPt.set(rayDirection);
+    tmpPt.scale(t);
+    tmpPt.add(rayStart);
+    intPt.setIntersectionPoint(tmpPt);
+    intPt.setT(t);
+    // Find UV coords
+    tmpDir.sub(intPt.getIntersectionPoint(), origin);
+    uvCoords.set(tmpDir.dot(uAxis), tmpDir.dot(vAxis));
+    return true;
+  }
+
+  private void setEverything(Vec3f normal,
+                             Vec3f origin,
+                             Vec3f uAxis,
+                             Vec3f vAxis) {
+    this.normal.set(normal);
+    this.origin.set(origin);
+    this.uAxis.set(uAxis);
+    this.vAxis.set(vAxis);
+    this.normal.normalize();
+    this.uAxis.normalize();
+    this.vAxis.normalize();
+  }
+}