| /* |
| * Copyright (c) 2009-2010 jMonkeyEngine |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * * Neither the name of 'jMonkeyEngine' nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package com.jme3.shadow; |
| |
| import com.jme3.bounding.BoundingBox; |
| import com.jme3.math.FastMath; |
| import com.jme3.math.Matrix4f; |
| import com.jme3.renderer.Camera; |
| import com.jme3.renderer.queue.GeometryList; |
| import static java.lang.Math.max; |
| import static java.lang.Math.min; |
| |
| /** |
| * Includes various useful shadow mapping functions. |
| * |
| * @see |
| * <ul> |
| * <li><a href="http://appsrv.cse.cuhk.edu.hk/~fzhang/pssm_vrcia/">http://appsrv.cse.cuhk.edu.hk/~fzhang/pssm_vrcia/</a></li> |
| * <li><a href="http://http.developer.nvidia.com/GPUGems3/gpugems3_ch10.html">http://http.developer.nvidia.com/GPUGems3/gpugems3_ch10.html</a></li> |
| * </ul> |
| * for more info. |
| */ |
| public final class PssmShadowUtil { |
| |
| /** |
| * Updates the frustum splits stores in <code>splits</code> using PSSM. |
| */ |
| public static void updateFrustumSplits(float[] splits, float near, float far, float lambda) { |
| for (int i = 0; i < splits.length; i++) { |
| float IDM = i / (float) splits.length; |
| float log = near * FastMath.pow((far / near), IDM); |
| float uniform = near + (far - near) * IDM; |
| splits[i] = log * lambda + uniform * (1.0f - lambda); |
| } |
| |
| // This is used to improve the correctness of the calculations. Our main near- and farplane |
| // of the camera always stay the same, no matter what happens. |
| splits[0] = near; |
| splits[splits.length - 1] = far; |
| } |
| |
| /** |
| * Compute the Zfar in the model vieuw to adjust the Zfar distance for the splits calculation |
| */ |
| public static float computeZFar(GeometryList occ, GeometryList recv, Camera cam) { |
| Matrix4f mat = cam.getViewMatrix(); |
| BoundingBox bbOcc = ShadowUtil.computeUnionBound(occ, mat); |
| BoundingBox bbRecv = ShadowUtil.computeUnionBound(recv, mat); |
| |
| return min(max(bbOcc.getZExtent() - bbOcc.getCenter().z, bbRecv.getZExtent() - bbRecv.getCenter().z), cam.getFrustumFar()); |
| } |
| } |