/**
* Java Modular Image Synthesis Toolkit (JMIST)
* Copyright (C) 2008-2013 Bradley W. Kimmel
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
package ca.eandb.jmist.framework.material.biospec;
import ca.eandb.jmist.framework.Random;
import ca.eandb.jmist.framework.ScatteredRay;
import ca.eandb.jmist.framework.SurfacePoint;
import ca.eandb.jmist.framework.color.WavelengthPacket;
import ca.eandb.jmist.framework.material.OpaqueMaterial;
import ca.eandb.jmist.framework.random.SimpleRandom;
import ca.eandb.jmist.framework.random.ThreadLocalRandom;
import ca.eandb.jmist.math.Basis3;
import ca.eandb.jmist.math.MathUtil;
import ca.eandb.jmist.math.Ray3;
import ca.eandb.jmist.math.SphericalCoordinates;
import ca.eandb.jmist.math.Vector3;
/**
* @author bwkimmel
*
*/
public class TabularPerturbingMaterial extends OpaqueMaterial {
// private final double[] wavelengths;
/** Serialization version ID. */
private static final long serialVersionUID = 359194554532848287L;
private final double[] lut;
private final Random rnd = new ThreadLocalRandom(new SimpleRandom());
public TabularPerturbingMaterial(
double[] exitantAngles, double[] cdf, int tableSize) {
lut = new double[tableSize];
for (int j = 0; j < tableSize; j++) {
lut[j] = MathUtil.interpolate(cdf, exitantAngles, (double) j / (double) (tableSize - 1));
}
}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.material.AbstractMaterial#scatter(ca.eandb.jmist.framework.SurfacePoint, ca.eandb.jmist.math.Vector3, boolean, ca.eandb.jmist.framework.color.WavelengthPacket, double, double, double)
*/
@Override
public ScatteredRay scatter(SurfacePoint x, Vector3 v, boolean adjoint,
WavelengthPacket lambda, double ru, double rv, double rj) {
Basis3 basis = Basis3.fromW(v);
Vector3 N = x.getNormal();
boolean inDir = (v.dot(N) < 0.0);
boolean outDir;
do {
int j = (int) Math.floor(rnd.next() * (double) lut.length);
double theta = lut[j];
double phi = 2.0 * Math.PI * rnd.next();
SphericalCoordinates sc = new SphericalCoordinates(theta, phi);
v = sc.toCartesian(basis);
outDir = (v.dot(N) < 0.0);
} while (inDir != outDir);
return ScatteredRay.diffuse(new Ray3(x.getPosition(), v), lambda.getColorModel().getWhite(lambda), 1.0);
}
}