Changed how roughness is stored into prefiltered env map mipmaps for a more consistent method.

Bumped the default size of the LightProbe maps to 256
Change he integrateBRDF approximation method

jme3-core/src/main/java/com/jme3/environment/EnvironmentCamera.java

@@ -111,7 +111,7 @@ public class EnvironmentCamera extends BaseAppState {
     /**
      * The size of environment cameras.
      */
-    protected int size = 128;
+    protected int size = 256;
 
     private final List<SnapshotJob> jobs = new ArrayList<SnapshotJob>();
 

jme3-core/src/main/java/com/jme3/environment/LightProbeFactory.java

@@ -280,6 +280,8 @@ public class LightProbeFactory {
 
             jobState.done[index] = true;
             if (jobState.isDone()) {
+                int nbMipMap = (int) (Math.log(probe.getPrefilteredEnvMap().getImage().getWidth()) / Math.log(2) - 1);
+                probe.setNbMipMaps(nbMipMap);
                 probe.setReady(true);
                 if (globalListener != null) {
                     globalListener.done(probe);

jme3-core/src/main/java/com/jme3/environment/generation/IrradianceMapGenerator.java

@@ -44,7 +44,7 @@ import java.util.concurrent.Callable;
 
 /**
  *
- * Generates the Irrafiance map for PBR. This job can be lauched from a separate
+ * Generates the Irradiance map for PBR. This job can be lauched from a separate
  * thread.
  *
  * TODO there is a lot of duplicate code here with the EnvMapUtils.

jme3-core/src/main/java/com/jme3/environment/generation/PrefilteredEnvMapFaceGenerator.java

@@ -34,13 +34,13 @@ package com.jme3.environment.generation;
 import com.jme3.environment.util.CubeMapWrapper;
 import com.jme3.environment.util.EnvMapUtils;
 import com.jme3.app.Application;
-import com.jme3.math.ColorRGBA;
+import com.jme3.math.*;
+
 import static com.jme3.math.FastMath.abs;
 import static com.jme3.math.FastMath.clamp;
 import static com.jme3.math.FastMath.pow;
 import static com.jme3.math.FastMath.sqrt;
-import com.jme3.math.Vector3f;
-import com.jme3.math.Vector4f;
+
 import com.jme3.texture.TextureCubeMap;
 import static com.jme3.environment.util.EnvMapUtils.getHammersleyPoint;
 import static com.jme3.environment.util.EnvMapUtils.getRoughnessFromMip;
@@ -184,7 +184,7 @@ public class PrefilteredEnvMapFaceGenerator extends RunnableWithProgress {
             for (int y = 0; y < targetMipMapSize; y++) {
                 for (int x = 0; x < targetMipMapSize; x++) {
                     color.set(0, 0, 0);
-                    getVectorFromCubemapFaceTexCoord(x, y, targetMipMapSize, face, texelVect, EnvMapUtils.FixSeamsMethod.Wrap);
+                    getVectorFromCubemapFaceTexCoord(x, y, targetMipMapSize, face, texelVect, EnvMapUtils.FixSeamsMethod.None);
                     prefilterEnvMapTexel(sourceWrapper, roughness, texelVect, nbSamples, color);
                     
                     outColor.set(Math.max(color.x, 0.0001f), Math.max(color.y,0.0001f), Math.max(color.z, 0.0001f), 1);
@@ -207,7 +207,6 @@ public class PrefilteredEnvMapFaceGenerator extends RunnableWithProgress {
         // a = roughness² and a2 = a²
         float a2 = roughness * roughness;
         a2 *= a2;
-        a2 *= 10;
         for (int i = 0; i < numSamples; i++) {
             Xi = getHammersleyPoint(i, numSamples, Xi);
             H = importanceSampleGGX(Xi, a2, N, H);
@@ -227,8 +226,11 @@ public class PrefilteredEnvMapFaceGenerator extends RunnableWithProgress {
                 totalWeight += NoL;
             }
         }
+        if (totalWeight > 0) {
+            prefilteredColor.divideLocal(totalWeight);
+        }
 
-        return prefilteredColor.divideLocal(totalWeight);
+        return prefilteredColor;
     }
 
     public Vector3f importanceSampleGGX(Vector4f xi, float a2, Vector3f normal, Vector3f store) {

jme3-core/src/main/java/com/jme3/environment/util/EnvMapUtils.java

@@ -33,9 +33,7 @@ package com.jme3.environment.util;
 
 import com.jme3.asset.AssetManager;
 import com.jme3.material.Material;
-import com.jme3.math.ColorRGBA;
-import com.jme3.math.Vector3f;
-import com.jme3.math.Vector4f;
+import com.jme3.math.*;
 import com.jme3.scene.Geometry;
 import com.jme3.scene.Node;
 import com.jme3.scene.shape.Quad;
@@ -49,8 +47,7 @@ import com.jme3.util.BufferUtils;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import static com.jme3.math.FastMath.*;
-import com.jme3.math.Quaternion;
-import com.jme3.math.Vector2f;
+
 import com.jme3.util.TempVars;
 
 /**
@@ -254,7 +251,7 @@ public class EnvMapUtils {
         float v;
 
         if (fixSeamsMethod == FixSeamsMethod.Stretch) {
-            /* Code from Nvtt : http://code.google.com/p/nvidia-texture-tools/source/browse/trunk/src/nvtt/CubeSurface.cpp		
+            /* Code from Nvtt : https://github.com/castano/nvidia-texture-tools/blob/master/src/nvtt/CubeSurface.cpp#L77
              * transform from [0..res - 1] to [-1 .. 1], match up edges exactly. */
             u = (2.0f * (float) x / ((float) mapSize - 1.0f)) - 1.0f;
             v = (2.0f * (float) y / ((float) mapSize - 1.0f)) - 1.0f;
@@ -274,7 +271,7 @@ public class EnvMapUtils {
         }
 
         //compute vector depending on the face
-        // Code from Nvtt : http://code.google.com/p/nvidia-texture-tools/source/browse/trunk/src/nvtt/CubeSurface.cpp	
+        // Code from Nvtt : https://github.com/castano/nvidia-texture-tools/blob/master/src/nvtt/CubeSurface.cpp#L101
         switch (face) {
             case 0:
                 store.set(1f, -v, -u);
@@ -387,62 +384,21 @@ public class EnvMapUtils {
         return face;
     }
 
-    /*
-    public static void main(String... argv) {
-
-//        for (int givenFace = 0; givenFace < 6; givenFace++) {
-//
-//            //int givenFace = 1;
-//            for (int x = 0; x < 128; x++) {
-//                for (int y = 0; y < 128; y++) {
-//                    Vector3f v = EnvMapUtils.getVectorFromCubemapFaceTexCoord(x, y, 128, givenFace, null, FixSeamsMethod.None);
-//                    Vector2f uvs = new Vector2f();
-//                    int face = EnvMapUtils.getCubemapFaceTexCoordFromVector(v, 128, uvs, FixSeamsMethod.None);
-//
-//                    if ((int) uvs.x != x || (int) uvs.y != y) {
-//                        System.err.println("error " + uvs + " should be " + x + "," + y + " vect was " + v);
-//                    }
-//                    if (givenFace != face) {
-//                        System.err.println("error face: " + face + " should be " + givenFace);
-//                    }
-//                }
-//            }
-//        }
-//        System.err.println("done ");
-        int total = 0;
-        for (int i = 0; i < 6; i++) {
-            int size = (int) pow(2, 7 - i);
-            int samples = EnvMapUtils.getSampleFromMip(i, 6);
-            int iterations = (samples * size * size);
-            total += iterations;
-            float roughness = EnvMapUtils.getRoughnessFromMip(i, 6);
-            System.err.println("roughness " + i + " : " + roughness + " , map : " + size + " , samples : " + samples + " , iterations : " + iterations);
-            System.err.println("reverse " + EnvMapUtils.getMipFromRoughness(roughness, 6));
-
-        }
-        System.err.println("total " + total);
-        System.err.println(128 * 128 * 1024);
-        System.err.println("test " + EnvMapUtils.getMipFromRoughness(0.9999f, 6));
-        System.err.println("nb mip = " + (Math.log(128) / Math.log(2) - 1));
-
-    }*/
-
-    public static int getSampleFromMip(int mipLevel, int miptot) {        
-        return mipLevel==0?1:Math.min(1 << (miptot - 1 + (mipLevel) * 2 ), 8192);
+    public static int getSampleFromMip(int mipLevel, int miptot) {
+        return mipLevel == 0 ? 1 : Math.min(1 << (miptot - 1 + (mipLevel) * 2), 8192);
     }
 
-    public static float getRoughnessFromMip(int miplevel, int miptot) {
-        float mipScale = 1.0f;
-        float mipOffset = -0.3f;
 
-        return pow(2, (miplevel - (miptot - 1) + mipOffset) / mipScale);
+    //see lagarde's paper https://seblagarde.files.wordpress.com/2015/07/course_notes_moving_frostbite_to_pbr_v32.pdf
+    //linear roughness
+    public static float getRoughnessFromMip(int miplevel, int miptot) {
+        float step = 1f / ((float) miptot - 1);
+        step *= miplevel;
+        return step * step;
     }
 
     public static float getMipFromRoughness(float roughness, int miptot) {
-        float mipScale = 1.0f;
-        float Lod = (float) (Math.log(roughness) / Math.log(2)) * mipScale + miptot - 1.0f;       
-
-        return (float) Math.max(0.0, Lod);
+        return FastMath.sqrt(roughness) * (miptot - 1);
     }
 
     /**
@@ -559,138 +515,6 @@ public class EnvMapUtils {
         shDir[7] = -(sqrt15Pi * xV * zV) / 2f;
         shDir[8] = sqrt15Pi * (x2 - y2) / 4f;
         
-//        shDir[0]  = (1f/(2.f*sqrtPi));
-//
-//	shDir[1]  = -(sqrt(3f/pi)*yV)/2.f;
-//	shDir[2]  = (sqrt(3/pi)*zV)/2.f;
-//	shDir[3]  = -(sqrt(3/pi)*xV)/2.f;
-//
-//	shDir[4]  = (sqrt(15f/pi)*xV*yV)/2.f;
-//	shDir[5]  = -(sqrt(15f/pi)*yV*zV)/2.f;
-//	shDir[6]  = (sqrt(5f/pi)*(-1 + 3f*z2))/4.f;
-//	shDir[7]  = -(sqrt(15f/pi)*xV*zV)/2.f;
-//	shDir[8]  = sqrt(15f/pi)*(x2 - y2)/4.f;
-
-
-    }
-
-    /**
-     * {@link EnvMapUtils#generateIrradianceMap(com.jme3.math.Vector3f[], com.jme3.texture.TextureCubeMap, int, com.jme3.utils.EnvMapUtils.FixSeamsMethod)
-     * }
-     *
-     * @param shCoeffs the spherical harmonics coefficients to use
-     * @param targetMapSize the size of the target map
-     * @return the irradiance map.
-     */
-    public static TextureCubeMap generateIrradianceMap(Vector3f[] shCoeffs, int targetMapSize) {
-        return generateIrradianceMap(shCoeffs, targetMapSize, FixSeamsMethod.Wrap, null);
-    }
-
-    /**
-     * Generates the Irradiance map (used for image based difuse lighting) from
-     * Spherical Harmonics coefficients previously computed with
-     * {@link EnvMapUtils#getSphericalHarmonicsCoefficents(com.jme3.texture.TextureCubeMap)}
-     * Note that the output cube map is in RGBA8 format.
-     *
-     * @param shCoeffs the SH coeffs
-     * @param targetMapSize the size of the irradiance map to generate
-     * @param fixSeamsMethod the method to fix seams
-     * @param store
-     * @return The irradiance cube map for the given coefficients
-     */
-    public static TextureCubeMap generateIrradianceMap(Vector3f[] shCoeffs, int targetMapSize, FixSeamsMethod fixSeamsMethod, TextureCubeMap store) {
-        TextureCubeMap irrCubeMap = store;
-        if (irrCubeMap == null) {
-            irrCubeMap = new TextureCubeMap(targetMapSize, targetMapSize, Image.Format.RGB16F);
-            irrCubeMap.setMagFilter(Texture.MagFilter.Bilinear);
-            irrCubeMap.setMinFilter(Texture.MinFilter.BilinearNoMipMaps);
-            irrCubeMap.getImage().setColorSpace(ColorSpace.Linear);
-        }
-
-        for (int i = 0; i < 6; i++) {
-            ByteBuffer buf = BufferUtils.createByteBuffer(targetMapSize * targetMapSize * irrCubeMap.getImage().getFormat().getBitsPerPixel()/8);
-            irrCubeMap.getImage().setData(i, buf);
-        }
-
-        Vector3f texelVect = new Vector3f();
-        ColorRGBA color = new ColorRGBA(ColorRGBA.Black);
-        float[] shDir = new float[9];
-        CubeMapWrapper envMapWriter = new CubeMapWrapper(irrCubeMap);
-        for (int face = 0; face < 6; face++) {
-
-            for (int y = 0; y < targetMapSize; y++) {
-                for (int x = 0; x < targetMapSize; x++) {
-                    getVectorFromCubemapFaceTexCoord(x, y, targetMapSize, face, texelVect, fixSeamsMethod);
-                    evalShBasis(texelVect, shDir);
-                    color.set(0, 0, 0, 0);
-                    for (int i = 0; i < NUM_SH_COEFFICIENT; i++) {
-                        color.set(color.r + shCoeffs[i].x * shDir[i] * shBandFactor[i],
-                                color.g + shCoeffs[i].y * shDir[i] * shBandFactor[i],
-                                color.b + shCoeffs[i].z * shDir[i] * shBandFactor[i],
-                                1.0f);
-                    }
-                    
-                    //clamping the color because very low value close to zero produce artifacts
-                    color.r = Math.max(0.0001f, color.r);
-                    color.g = Math.max(0.0001f, color.g);
-                    color.b = Math.max(0.0001f, color.b);
-                    envMapWriter.setPixel(x, y, face, color);
-                }
-            }
-        }
-        return irrCubeMap;
-    }
-
-    /**
-     * Generates the prefiltered env map (used for image based specular
-     * lighting) With the GGX/Shlick brdf
-     * {@link EnvMapUtils#getSphericalHarmonicsCoefficents(com.jme3.texture.TextureCubeMap)}
-     * Note that the output cube map is in RGBA8 format.
-     *
-     * @param sourceEnvMap
-     * @param targetMapSize the size of the irradiance map to generate
-     * @param store
-     * @param fixSeamsMethod the method to fix seams
-     * @return The irradiance cube map for the given coefficients
-     */
-    public static TextureCubeMap generatePrefilteredEnvMap(TextureCubeMap sourceEnvMap, int targetMapSize, FixSeamsMethod fixSeamsMethod, TextureCubeMap store) {
-        TextureCubeMap pem = store;
-        if (pem == null) {
-            pem = new TextureCubeMap(targetMapSize, targetMapSize, Image.Format.RGB16F);
-            pem.setMagFilter(Texture.MagFilter.Bilinear);
-            pem.setMinFilter(Texture.MinFilter.Trilinear);
-            pem.getImage().setColorSpace(ColorSpace.Linear);
-        }
-
-        int nbMipMap = (int) (Math.log(targetMapSize) / Math.log(2) - 1);
-
-        CubeMapWrapper sourceWrapper = new CubeMapWrapper(sourceEnvMap);
-        CubeMapWrapper targetWrapper = new CubeMapWrapper(pem);
-        targetWrapper.initMipMaps(nbMipMap);
-
-        Vector3f texelVect = new Vector3f();
-        Vector3f color = new Vector3f();
-        ColorRGBA outColor = new ColorRGBA();
-        for (int mipLevel = 0; mipLevel < nbMipMap; mipLevel++) {
-            System.err.println("mip level " + mipLevel);
-            float roughness = getRoughnessFromMip(mipLevel, nbMipMap);
-            int nbSamples = getSampleFromMip(mipLevel, nbMipMap);
-            int targetMipMapSize = (int) pow(2, nbMipMap + 1 - mipLevel);
-            for (int face = 0; face < 6; face++) {
-                System.err.println("face " + face);
-                for (int y = 0; y < targetMipMapSize; y++) {
-                    for (int x = 0; x < targetMipMapSize; x++) {
-                        color.set(0, 0, 0);
-                        getVectorFromCubemapFaceTexCoord(x, y, targetMipMapSize, face, texelVect, FixSeamsMethod.Wrap);
-                        prefilterEnvMapTexel(sourceWrapper, roughness, texelVect, nbSamples, color);
-                        outColor.set(color.x, color.y, color.z, 1.0f);
-                        // System.err.println("coords " + x + "," + y);
-                        targetWrapper.setPixel(x, y, face, mipLevel, outColor);
-                    }
-                }
-            }
-        }
-        return pem;
     }
 
     public static Vector4f getHammersleyPoint(int i, final int nbrSample, Vector4f store) {
@@ -719,43 +543,6 @@ public class EnvMapUtils {
         return store;
     }
 
-    private static Vector3f prefilterEnvMapTexel(CubeMapWrapper envMapReader, float roughness, Vector3f N, int numSamples, Vector3f store) {        
-
-        Vector3f prefilteredColor = store;
-        float totalWeight = 0.0f;
-
-        TempVars vars = TempVars.get();
-        Vector4f Xi = vars.vect4f1;
-        Vector3f H = vars.vect1;
-        Vector3f tmp = vars.vect2;
-        ColorRGBA c = vars.color;
-        // a = roughness² and a2 = a²
-        float a2 = roughness * roughness;
-        a2 *= a2;
-        a2 *= 10;
-        for (int i = 0; i < numSamples; i++) {
-            Xi = getHammersleyPoint(i, numSamples, Xi);            
-            H = importanceSampleGGX(Xi, a2, N, H, vars);
-
-            H.normalizeLocal();
-            tmp.set(H);
-            float NoH = N.dot(tmp);
-
-            Vector3f L = tmp.multLocal(NoH * 2).subtractLocal(N);
-            float NoL = clamp(N.dot(L), 0.0f, 1.0f);
-            if (NoL > 0) {
-                envMapReader.getPixel(L, c);
-                prefilteredColor.setX(prefilteredColor.x + c.r * NoL);
-                prefilteredColor.setY(prefilteredColor.y + c.g * NoL);
-                prefilteredColor.setZ(prefilteredColor.z + c.b * NoL);
-
-                totalWeight += NoL;
-            }
-        }
-        vars.release();
-        return prefilteredColor.divideLocal(totalWeight);
-    }
-
     public static Vector3f importanceSampleGGX(Vector4f xi, float a2, Vector3f normal, Vector3f store, TempVars vars) {
         if (store == null) {
             store = new Vector3f();
@@ -945,3 +732,5 @@ public class EnvMapUtils {
         return pem;
     }
 }
+
+

jme3-core/src/main/java/com/jme3/light/LightProbe.java

@@ -81,6 +81,7 @@ public class LightProbe extends Light implements Savable {
     private boolean ready = false;
     private Vector3f position = new Vector3f();
     private Node debugNode;
+    private int nbMipMaps;
 
     /**
      * Empty constructor used for serialization. 
@@ -226,6 +227,14 @@ public class LightProbe extends Light implements Savable {
         getBounds().setCenter(position);
     }
 
+    public int getNbMipMaps() {
+        return nbMipMaps;
+    }
+
+    public void setNbMipMaps(int nbMipMaps) {
+        this.nbMipMaps = nbMipMaps;
+    }
+
     @Override
     public boolean intersectsBox(BoundingBox box, TempVars vars) {
         return getBounds().intersectsBoundingBox(box);

jme3-core/src/main/java/com/jme3/material/logic/SinglePassAndImageBasedLightingLogic.java

@@ -128,10 +128,10 @@ public final class SinglePassAndImageBasedLightingLogic extends DefaultTechnique
             ambientColor.setValue(VarType.Vector4, ambientLightColor);
         }
 
-        //If there is a lightProbe in the list we force it's render on the first pass
+        //If there is a lightProbe in the list we force its render on the first pass
         if(lightProbe != null){
             BoundingSphere s = (BoundingSphere)lightProbe.getBounds();
-            lightProbeData.setVector4InArray(lightProbe.getPosition().x, lightProbe.getPosition().y, lightProbe.getPosition().z, 1f/s.getRadius(), 0);
+            lightProbeData.setVector4InArray(lightProbe.getPosition().x, lightProbe.getPosition().y, lightProbe.getPosition().z, 1f / s.getRadius() + lightProbe.getNbMipMaps(), 0);
             //assigning new texture indexes
             int irrUnit = lastTexUnit++;
             int pemUnit = lastTexUnit++;

jme3-core/src/main/resources/Common/MatDefs/Light/PBRLighting.frag

@@ -244,8 +244,10 @@ void main(){
     #ifdef INDIRECT_LIGHTING
         vec3 rv = reflect(-viewDir.xyz, normal.xyz);
         //prallax fix for spherical bounds from https://seblagarde.wordpress.com/2012/09/29/image-based-lighting-approaches-and-parallax-corrected-cubemap/
-        // g_LightProbeData.w is 1/probe radius, g_LightProbeData.xyz is the position of the lightProbe.
-        rv = g_LightProbeData.w * (wPosition - g_LightProbeData.xyz) +rv;
+        // g_LightProbeData.w is 1/probe radius + nbMipMaps, g_LightProbeData.xyz is the position of the lightProbe.
+        float invRadius = fract( g_LightProbeData.w);
+        float nbMipMaps = g_LightProbeData.w - invRadius;
+        rv = invRadius * (wPosition - g_LightProbeData.xyz) +rv;
 
          //horizon fade from http://marmosetco.tumblr.com/post/81245981087
         float horiz = dot(rv, wNormal.xyz);
@@ -257,7 +259,7 @@ void main(){
         vec3 indirectSpecular = vec3(0.0);
         indirectDiffuse = textureCube(g_IrradianceMap, normal.xyz).rgb * diffuseColor.rgb;
 
-        indirectSpecular = ApproximateSpecularIBLPolynomial(g_PrefEnvMap, specularColor.rgb, Roughness, ndotv, rv.xyz);
+        indirectSpecular = ApproximateSpecularIBLPolynomial(g_PrefEnvMap, specularColor.rgb, Roughness, ndotv, rv.xyz, nbMipMaps);
         indirectSpecular *= vec3(horiz);
 
         vec3 indirectLighting =  indirectDiffuse + indirectSpecular;
@@ -273,7 +275,6 @@ void main(){
         #endif
         gl_FragColor += emissive * pow(emissive.a, m_EmissivePower) * m_EmissiveIntensity;
     #endif
-           
     gl_FragColor.a = alpha;
    
 }

jme3-core/src/main/resources/Common/ShaderLib/PBR.glsllib

@@ -106,46 +106,26 @@ void PBR_ComputeDirectLight(vec3 normal, vec3 lightDir, vec3 viewDir,
     outSpecular = vec3(specular) * lightColor;
 }
 
-//https://knarkowicz.wordpress.com/2014/12/27/analytical-dfg-term-for-ibl/
-vec3 EnvDFGPolynomial( vec3 specularColor, float roughness, float ndotv ){
-    float x = 1.0 - roughness;
-    float y = ndotv;
- 
-    float b1 = -0.1688;
-    float b2 = 1.895;
-    float b3 = 0.9903;
-    float b4 = -4.853;
-    float b5 = 8.404;
-    float b6 = -5.069;
-    float bias = clamp( min( b1 * x + b2 * x * x, b3 + b4 * y + b5 * y * y + b6 * y * y * y ), 0.0, 1.0 );
- 
-    float d0 = 0.6045;
-    float d1 = 1.699;
-    float d2 = -0.5228;
-    float d3 = -3.603;
-    float d4 = 1.404;
-    float d5 = 0.1939;
-    float d6 = 2.661;
-    float delta = clamp(( d0 + d1 * x + d2 * y + d3 * x * x + d4 * x * y + d5 * y * y + d6 * x * x * x ), 0.0, 1.0);
-    float scale = delta - bias;
- 
-    bias *= clamp( 2.5 / (roughness) * specularColor.y, 0.0, 1.0 );
-    return specularColor * scale + bias;
+vec3 integrateBRDFApprox( const in vec3 specular, float roughness, float NoV ){
+    const vec4 c0 = vec4( -1, -0.0275, -0.572, 0.022 );
+    const vec4 c1 = vec4( 1, 0.0425, 1.04, -0.04 );
+    vec4 r = roughness * c0 + c1;
+    float a004 = min( r.x * r.x, exp2( -9.28 * NoV ) ) * r.x + r.y;
+    vec2 AB = vec2( -1.04, 1.04 ) * a004 + r.zw;
+    return specular * AB.x + AB.y;
 }
 
-vec3 ApproximateSpecularIBL(samplerCube envMap,sampler2D integrateBRDF, vec3 SpecularColor , float Roughness, float ndotv, vec3 refVec){
-    //TODO magic values should be replaced by defines.
-    float Lod = log2(Roughness) * 1.1 + 6.0 - 2.0;
+vec3 ApproximateSpecularIBL(samplerCube envMap,sampler2D integrateBRDF, vec3 SpecularColor , float Roughness, float ndotv, vec3 refVec, float nbMipMaps){
+    float Lod = sqrt( Roughness ) * (nbMipMaps - 1.0);
     vec3 PrefilteredColor =  textureCubeLod(envMap, refVec.xyz,Lod).rgb;
     vec2 EnvBRDF = texture2D(integrateBRDF,vec2(Roughness, ndotv)).rg;
     return PrefilteredColor * ( SpecularColor * EnvBRDF.x+ EnvBRDF.y );    
 }
 
-vec3 ApproximateSpecularIBLPolynomial(samplerCube envMap, vec3 SpecularColor , float Roughness, float ndotv, vec3 refVec){
-    //TODO magic values should be replaced by defines.
-    float Lod = log2(Roughness) * 1.6 + 5.0;
+vec3 ApproximateSpecularIBLPolynomial(samplerCube envMap, vec3 SpecularColor , float Roughness, float ndotv, vec3 refVec, float nbMipMaps){
+    float Lod = sqrt( Roughness ) * (nbMipMaps - 1.0);
     vec3 PrefilteredColor =  textureCubeLod(envMap, refVec.xyz, Lod).rgb;
-    return PrefilteredColor * EnvDFGPolynomial(SpecularColor, Roughness, ndotv);
+    return PrefilteredColor * integrateBRDFApprox(SpecularColor, Roughness, ndotv);
 }
 
 

jme3-examples/src/main/java/jme3test/light/pbr/RefEnv.java

@@ -18,7 +18,7 @@ import com.jme3.scene.Geometry;
 import com.jme3.scene.Node;
 import com.jme3.scene.Spatial;
 import com.jme3.ui.Picture;
-import com.jme3.util.MaterialDebugAppState;
+import com.jme3.util.SkyFactory;
 
 /**
  * test
@@ -29,8 +29,7 @@ public class RefEnv extends SimpleApplication {
 
     private Node tex;
     private Node ref;
-    private Picture refDE;
-    private Picture refM;
+    private Picture refImg;
 
     public static void main(String[] args) {
         RefEnv app = new RefEnv();
@@ -40,25 +39,25 @@ public class RefEnv extends SimpleApplication {
     @Override
     public void simpleInitApp() {
 
-        cam.setLocation(new Vector3f(-2.3324413f, 2.9567573f, 4.6054406f));
-        cam.setRotation(new Quaternion(0.06310794f, 0.9321281f, -0.29613864f, 0.1986369f));
-        Spatial sc = assetManager.loadModel("Scenes/PBR/spheres.j3o");
+        cam.setLocation(new Vector3f(-17.713732f, 1.8661976f, 17.156784f));
+        cam.setRotation(new Quaternion(0.021403445f, 0.9428821f, -0.06178002f, 0.32664734f));
+        flyCam.setDragToRotate(true);
+        flyCam.setMoveSpeed(5);
+        Spatial sc = assetManager.loadModel("Models/gltf/ref/scene.gltf");
         rootNode.attachChild(sc);
-        rootNode.getChild("Scene").setCullHint(Spatial.CullHint.Always);
+        Spatial sky = SkyFactory.createSky(assetManager, "Textures/Sky/Path.hdr", SkyFactory.EnvMapType.EquirectMap);
+        rootNode.attachChild(sky);
+        rootNode.getChild(0).setCullHint(Spatial.CullHint.Always);
 
         ref = new Node("reference pictures");
-        refDE = new Picture("refDE");
-        refDE.setHeight(cam.getHeight());
-        refDE.setWidth(cam.getWidth());
-        refDE.setImage(assetManager,"jme3test/light/pbr/spheresRefDE.png", false);
-        refM = new Picture("refM");
-        refM.setImage(assetManager,"jme3test/light/pbr/spheresRefM.png", false);
-        refM.setHeight(cam.getHeight());
-        refM.setWidth(cam.getWidth());
+        refImg = new Picture("refImg");
+        refImg.setHeight(cam.getHeight());
+        refImg.setWidth(cam.getWidth());
+        refImg.setImage(assetManager, "jme3test/light/pbr/ref.png", false);
 
-        ref.attachChild(refDE);
+        ref.attachChild(refImg);
 
-        stateManager.attach(new EnvironmentCamera());
+        stateManager.attach(new EnvironmentCamera(256, Vector3f.ZERO));
 
         inputManager.addMapping("tex", new KeyTrigger(KeyInput.KEY_SPACE));
         inputManager.addMapping("switch", new KeyTrigger(KeyInput.KEY_RETURN));
@@ -105,13 +104,11 @@ public class RefEnv extends SimpleApplication {
             if (((Float) mat.getParam("Metallic").getValue()) == 1f) {
                 mat.setFloat("Metallic", 0);
                 mat.setColor("BaseColor", ColorRGBA.Black);
-                ref.attachChild(refDE);
-                refM.removeFromParent();
+                ref.attachChild(refImg);
             } else {
                 mat.setFloat("Metallic", 1);
                 mat.setColor("BaseColor", ColorRGBA.White);
-                ref.attachChild(refM);
-                refDE.removeFromParent();
+                refImg.removeFromParent();
             }
         }
     }
@@ -130,7 +127,7 @@ public class RefEnv extends SimpleApplication {
                     System.err.println("Done rendering env maps");
                     tex = EnvMapUtils.getCubeMapCrossDebugViewWithMipMaps(result.getPrefilteredEnvMap(), assetManager);
                   //  guiNode.attachChild(tex);
-                    rootNode.getChild("Scene").setCullHint(Spatial.CullHint.Dynamic);
+                    rootNode.getChild(0).setCullHint(Spatial.CullHint.Dynamic);
                 }
             });
             ((BoundingSphere) probe.getBounds()).setRadius(100);

jme3-examples/src/main/java/jme3test/light/pbr/TestPBRLighting.java

@@ -78,8 +78,9 @@ public class TestPBRLighting extends SimpleApplication {
     private Geometry model;
     private DirectionalLight dl;
     private Node modelNode;
-    private int frame = 0;   
-    private Material pbrMat;    
+    private int frame = 0;
+    private Material pbrMat;
+    private float roughness = 1.0f;
 
     @Override
     public void simpleInitApp() {
@@ -93,16 +94,16 @@ public class TestPBRLighting extends SimpleApplication {
 
         dl = new DirectionalLight();
         dl.setDirection(new Vector3f(-1, -1, -1).normalizeLocal());
-        rootNode.addLight(dl);
+        //       rootNode.addLight(dl);
         dl.setColor(ColorRGBA.White);
         rootNode.attachChild(modelNode);
 
-      
+
         FilterPostProcessor fpp = new FilterPostProcessor(assetManager);
 //        fpp.addFilter(new FXAAFilter());
         fpp.addFilter(new ToneMapFilter(Vector3f.UNIT_XYZ.mult(4.0f)));
 //        fpp.addFilter(new SSAOFilter(0.5f, 3, 0.2f, 0.2f));
-        viewPort.addProcessor(fpp);
+        // viewPort.addProcessor(fpp);
 
         //Spatial sky = SkyFactory.createSky(assetManager, "Textures/Sky/Sky_Cloudy.hdr", SkyFactory.EnvMapType.EquirectMap);
         Spatial sky = SkyFactory.createSky(assetManager, "Textures/Sky/Path.hdr", SkyFactory.EnvMapType.EquirectMap);
@@ -114,17 +115,17 @@ public class TestPBRLighting extends SimpleApplication {
         model.setMaterial(pbrMat);
 
 
-        final EnvironmentCamera envCam = new EnvironmentCamera(128, new Vector3f(0, 3f, 0));
+        final EnvironmentCamera envCam = new EnvironmentCamera(256, new Vector3f(0, 3f, 0));
         stateManager.attach(envCam);
-        
+
 //        EnvironmentManager envManager = new EnvironmentManager();
 //        stateManager.attach(envManager);
-        
- //       envManager.setScene(rootNode);
-        
+
+        //       envManager.setScene(rootNode);
+
         LightsDebugState debugState = new LightsDebugState();
         stateManager.attach(debugState);
-        
+
         ChaseCamera chaser = new ChaseCamera(cam, modelNode, inputManager);
         chaser.setDragToRotate(true);
         chaser.setMinVerticalRotation(-FastMath.HALF_PI);
@@ -144,7 +145,7 @@ public class TestPBRLighting extends SimpleApplication {
                     }
                     if (tex.getParent() == null && tex2.getParent() == null) {
                         guiNode.attachChild(tex);
-                    } else if (tex2.getParent() == null){
+                    } else if (tex2.getParent() == null) {
                         tex.removeFromParent();
                         guiNode.attachChild(tex2);
                     } else {
@@ -152,6 +153,16 @@ public class TestPBRLighting extends SimpleApplication {
                     }
                 }
 
+                if (name.equals("rup") && isPressed) {
+                    roughness = FastMath.clamp(roughness + 0.1f, 0.0f, 1.0f);
+                    pbrMat.setFloat("Roughness", roughness);
+                }
+                if (name.equals("rdown") && isPressed) {
+                    roughness = FastMath.clamp(roughness - 0.1f, 0.0f, 1.0f);
+                    pbrMat.setFloat("Roughness", roughness);
+                }
+
+
                 if (name.equals("up") && isPressed) {
                     model.move(0, tpf * 100f, 0);
                 }
@@ -169,7 +180,7 @@ public class TestPBRLighting extends SimpleApplication {
                     dl.setDirection(cam.getDirection().normalize());
                 }
             }
-        }, "toggle", "light", "up", "down", "left", "right", "debug");
+        }, "toggle", "light", "up", "down", "left", "right", "debug", "rup", "rdown");
 
         inputManager.addMapping("toggle", new KeyTrigger(KeyInput.KEY_RETURN));
         inputManager.addMapping("light", new KeyTrigger(KeyInput.KEY_F));
@@ -178,8 +189,10 @@ public class TestPBRLighting extends SimpleApplication {
         inputManager.addMapping("left", new KeyTrigger(KeyInput.KEY_LEFT));
         inputManager.addMapping("right", new KeyTrigger(KeyInput.KEY_RIGHT));
         inputManager.addMapping("debug", new KeyTrigger(KeyInput.KEY_D));
-        
-        
+        inputManager.addMapping("rup", new KeyTrigger(KeyInput.KEY_T));
+        inputManager.addMapping("rdown", new KeyTrigger(KeyInput.KEY_G));
+
+
         MaterialDebugAppState debug = new MaterialDebugAppState();
         debug.registerBinding("Common/MatDefs/Light/PBRLighting.frag", rootNode);
         getStateManager().attach(debug);
@@ -201,10 +214,10 @@ public class TestPBRLighting extends SimpleApplication {
                     tex2 = EnvMapUtils.getCubeMapCrossDebugView(result.getIrradianceMap(), assetManager);
                 }
             });
-            ((BoundingSphere)probe.getBounds()).setRadius(100);
+            ((BoundingSphere) probe.getBounds()).setRadius(100);
             rootNode.addLight(probe);
             //getStateManager().getState(EnvironmentManager.class).addEnvProbe(probe);
-            
+
         }
         if (frame > 10 && modelNode.getParent() == null) {
             rootNode.attachChild(modelNode);