1 /* 2 * Copyright (c) 2009-2010 jMonkeyEngine 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 12 * * Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 24 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 27 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 package com.jme3.shadow; 33 34 import com.jme3.bounding.BoundingBox; 35 import com.jme3.math.FastMath; 36 import com.jme3.math.Matrix4f; 37 import com.jme3.renderer.Camera; 38 import com.jme3.renderer.queue.GeometryList; 39 import static java.lang.Math.max; 40 import static java.lang.Math.min; 41 42 /** 43 * Includes various useful shadow mapping functions. 44 * 45 * @see 46 * <ul> 47 * <li><a href="http://appsrv.cse.cuhk.edu.hk/~fzhang/pssm_vrcia/">http://appsrv.cse.cuhk.edu.hk/~fzhang/pssm_vrcia/</a></li> 48 * <li><a href="http://http.developer.nvidia.com/GPUGems3/gpugems3_ch10.html">http://http.developer.nvidia.com/GPUGems3/gpugems3_ch10.html</a></li> 49 * </ul> 50 * for more info. 51 */ 52 public final class PssmShadowUtil { 53 54 /** 55 * Updates the frustum splits stores in <code>splits</code> using PSSM. 56 */ updateFrustumSplits(float[] splits, float near, float far, float lambda)57 public static void updateFrustumSplits(float[] splits, float near, float far, float lambda) { 58 for (int i = 0; i < splits.length; i++) { 59 float IDM = i / (float) splits.length; 60 float log = near * FastMath.pow((far / near), IDM); 61 float uniform = near + (far - near) * IDM; 62 splits[i] = log * lambda + uniform * (1.0f - lambda); 63 } 64 65 // This is used to improve the correctness of the calculations. Our main near- and farplane 66 // of the camera always stay the same, no matter what happens. 67 splits[0] = near; 68 splits[splits.length - 1] = far; 69 } 70 71 /** 72 * Compute the Zfar in the model vieuw to adjust the Zfar distance for the splits calculation 73 */ computeZFar(GeometryList occ, GeometryList recv, Camera cam)74 public static float computeZFar(GeometryList occ, GeometryList recv, Camera cam) { 75 Matrix4f mat = cam.getViewMatrix(); 76 BoundingBox bbOcc = ShadowUtil.computeUnionBound(occ, mat); 77 BoundingBox bbRecv = ShadowUtil.computeUnionBound(recv, mat); 78 79 return min(max(bbOcc.getZExtent() - bbOcc.getCenter().z, bbRecv.getZExtent() - bbRecv.getCenter().z), cam.getFrustumFar()); 80 } 81 } 82