Added SoftBloomFilter

jme3-effects/src/main/java/com/jme3/post/filters/PBRBloomFilter.java

@@ -0,0 +1,262 @@
+/*
+ * Copyright (c) 2024 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.post.filters;
+
+import com.jme3.asset.AssetManager;
+import com.jme3.material.Material;
+import com.jme3.math.FastMath;
+import com.jme3.math.Vector2f;
+import com.jme3.post.Filter;
+import com.jme3.renderer.RenderManager;
+import com.jme3.renderer.Renderer;
+import com.jme3.renderer.ViewPort;
+import com.jme3.texture.Image;
+import java.util.LinkedList;
+
+/**
+ * Adds a glow effect to the scene.
+ * <p>
+ * Compared to {@link BloomFilter}, this filter produces much higher quality
+ * results that feel much more natural.
+ * <p>
+ * This implementation, unlike BloomFilter, has no brightness threshold,
+ * meaning all aspects of the scene glow, although only very bright areas will
+ * noticably produce glow. For this reason, this filter should <em>only</em> be used
+ * if HDR is also being utilized, otherwise BloomFilter should be preferred.
+ * <p>
+ * This filter uses the PBR bloom algorithm presented in
+ * <a href="https://learnopengl.com/Guest-Articles/2022/Phys.-Based-Bloom">this article</a>.
+ * 
+ * @author codex
+ */
+public class PBRBloomFilter extends Filter {
+
+    private AssetManager assetManager;
+    private RenderManager renderManager;
+    private ViewPort viewPort;
+    private int width, height;
+    private Pass[] downsamplingPasses;
+    private Pass[] upsamplingPasses;
+    private final Image.Format format = Image.Format.RGBA16F;
+    private boolean initialized = false;
+    private int numSamplingPasses = 5;
+    private float glowFactor = 0.05f;
+
+    /**
+     * Creates filter with default settings.
+     */
+    public PBRBloomFilter() {}
+
+    /**
+     * Creates filter with the given number of sampling passes.
+     * 
+     * @param numSamplingPasses 
+     * @see #setNumSamplingPasses(int)
+     */
+    public PBRBloomFilter(int numSamplingPasses) {
+        this.numSamplingPasses = numSamplingPasses;
+    }
+
+    /**
+     * Creates filter with given glow factor.
+     * 
+     * @param glowFactor
+     * @see #setGlowFactor(float)
+     */
+    public PBRBloomFilter(float glowFactor) {
+        this.glowFactor = glowFactor;
+    }
+
+    /**
+     * Creates filter with the given number of sampling passes and the given glow factor.
+     * 
+     * @param numSamplingPasses
+     * @param glowFactor 
+     * @see #setNumSamplingPasses(int)
+     * @see #setGlowFactor(float)
+     */
+    public PBRBloomFilter(int numSamplingPasses, float glowFactor) {
+        this.numSamplingPasses = numSamplingPasses;
+        this.glowFactor = glowFactor;
+    }
+
+    @Override
+    protected void initFilter(AssetManager am, RenderManager rm, ViewPort vp, int width, int height) {
+
+        assetManager = am;
+        renderManager = rm;
+        viewPort = vp;
+        postRenderPasses = new LinkedList<>();
+        Renderer renderer = renderManager.getRenderer();
+        int w = this.width = width;
+        int h = this.height = height;
+
+        downsamplingPasses = new Pass[numSamplingPasses];
+        upsamplingPasses = new Pass[numSamplingPasses];
+
+        // downsampling passes
+        Material downsampleMat = new Material(assetManager, "Common/MatDefs/Post/Downsample.j3md");
+        Vector2f initTexelSize = new Vector2f(1f/w, 1f/h);
+        w /= 2; h /= 2;
+        Pass initialPass = new Pass() {
+            @Override
+            public boolean requiresSceneAsTexture() {
+                return true;
+            }
+            @Override
+            public void beforeRender() {
+                downsampleMat.setVector2("TexelSize", initTexelSize);
+            }
+        };
+        initialPass.init(renderer, w, h, format, Image.Format.Depth, 1, downsampleMat);
+        postRenderPasses.add(initialPass);
+        downsamplingPasses[0] = initialPass;
+        for (int i = 1; i < downsamplingPasses.length; i++) {
+            Vector2f texelSize = new Vector2f(1f/w, 1f/h);
+            w /= 2; h /= 2;
+            Pass prev = downsamplingPasses[i-1];
+            Pass pass = new Pass() {
+                @Override
+                public void beforeRender() {
+                    downsampleMat.setTexture("Texture", prev.getRenderedTexture());
+                    downsampleMat.setVector2("TexelSize", texelSize);
+                }
+            };
+            pass.init(renderer, w, h, format, Image.Format.Depth, 1, downsampleMat);
+            postRenderPasses.add(pass);
+            downsamplingPasses[i] = pass;
+        }
+
+        // upsampling passes
+        Material upsampleMat = new Material(assetManager, "Common/MatDefs/Post/Upsample.j3md");
+        for (int i = 0; i < upsamplingPasses.length; i++) {
+            Vector2f texelSize = new Vector2f(1f/w, 1f/h);
+            w *= 2; h *= 2;
+            Pass prev;
+            if (i == 0) {
+                prev = downsamplingPasses[downsamplingPasses.length-1];
+            } else {
+                prev = upsamplingPasses[i-1];
+            }
+            Pass pass = new Pass() {
+                @Override
+                public void beforeRender() {
+                    upsampleMat.setTexture("Texture", prev.getRenderedTexture());
+                    upsampleMat.setVector2("TexelSize", texelSize);
+                }
+            };
+            pass.init(renderer, w, h, format, Image.Format.Depth, 1, upsampleMat);
+            postRenderPasses.add(pass);
+            upsamplingPasses[i] = pass;
+        }
+
+        material = new Material(assetManager, "Common/MatDefs/Post/PBRBloomFinal.j3md");
+        material.setTexture("GlowMap", upsamplingPasses[upsamplingPasses.length-1].getRenderedTexture());
+
+        initialized = true;
+
+    }
+
+    @Override
+    protected Material getMaterial() {
+        return material;
+    }
+
+    /**
+     * Sets the number of sampling passes in each step.
+     * <p>
+     * Higher values produce more glow with higher resolution, at the cost
+     * of more passes. Lower values produce less glow with lower resolution.
+     * <p>
+     * The total number of passes is {@code 2n+1}: n passes for downsampling
+     * (13 texture reads per pass per fragment), n passes for upsampling and blur
+     * (9 texture reads per pass per fragment), and 1 pass for blending (2 texture reads
+     * per fragment). Though, it should be noted that for each downsampling pass the
+     * number of fragments decreases by 75%, and for each upsampling pass, the number
+     * of fragments quadruples (which restores the number of fragments to the original
+     * resolution).
+     * <p>
+     * Settings this after the filter has been initialized forces reinitialization.
+     * <p>
+     * default=5
+     * 
+     * @param n number of passes per donwsampling/upsampling step
+     */
+    public void setNumSamplingPasses(int n) {
+        if (n <= 0) {
+            throw new IllegalArgumentException("Expected number of sampling passes to be greater than zero (found: "+n+").");
+        }
+        numSamplingPasses = n;
+        if (initialized) {
+            initFilter(assetManager, renderManager, viewPort, width, height);
+        }
+    }
+
+    /**
+     * Sets the factor at which the glow result texture is merged with
+     * the scene texture.
+     * <p>
+     * Low values favor the scene texture more, while high values make
+     * glow more noticable. This value is clamped between 0 and 1.
+     * <p>
+     * default=0.05f
+     * 
+     * @param factor 
+     */
+    public void setGlowFactor(float factor) {
+        this.glowFactor = FastMath.clamp(factor, 0, 1);
+        if (material != null) {
+            material.setFloat("GlowFactor", glowFactor);
+        }
+    }
+
+    /**
+     * Gets the number of downsampling/upsampling passes per step.
+     * 
+     * @return glow factor
+     * @see #setNumSamplingPasses(int)
+     */
+    public int getNumSamplingPasses() {
+        return numSamplingPasses;
+    }
+
+    /**
+     * Gets the glow factor.
+     * 
+     * @return glow factor
+     * @see #setGlowFactor(float)
+     */
+    public float getGlowFactor() {
+        return glowFactor;
+    }
+
+}

jme3-effects/src/main/resources/Common/MatDefs/Post/Downsample.frag

@@ -0,0 +1,60 @@
+
+#import "Common/ShaderLib/GLSLCompat.glsllib"
+#import "Common/ShaderLib/MultiSample.glsllib"
+
+uniform COLORTEXTURE m_Texture;
+uniform vec2 m_TexelSize;
+varying vec2 texCoord;
+
+void main() {
+
+    // downsampling code: https://learnopengl.com/Guest-Articles/2022/Phys.-Based-Bloom
+
+    float x = m_TexelSize.x;
+    float y = m_TexelSize.y;
+
+    // Take 13 samples around current texel
+    // a - b - c
+    // - j - k -
+    // d - e - f
+    // - l - m -
+    // g - h - i
+    // === ('e' is the current texel) ===
+    vec3 a = getColor(m_Texture, vec2(texCoord.x - 2*x, texCoord.y + 2*y)).rgb;
+    vec3 b = getColor(m_Texture, vec2(texCoord.x,       texCoord.y + 2*y)).rgb;
+    vec3 c = getColor(m_Texture, vec2(texCoord.x + 2*x, texCoord.y + 2*y)).rgb;
+
+    vec3 d = getColor(m_Texture, vec2(texCoord.x - 2*x, texCoord.y)).rgb;
+    vec3 e = getColor(m_Texture, vec2(texCoord.x,       texCoord.y)).rgb;
+    vec3 f = getColor(m_Texture, vec2(texCoord.x + 2*x, texCoord.y)).rgb;
+
+    vec3 g = getColor(m_Texture, vec2(texCoord.x - 2*x, texCoord.y - 2*y)).rgb;
+    vec3 h = getColor(m_Texture, vec2(texCoord.x,       texCoord.y - 2*y)).rgb;
+    vec3 i = getColor(m_Texture, vec2(texCoord.x + 2*x, texCoord.y - 2*y)).rgb;
+
+    vec3 j = getColor(m_Texture, vec2(texCoord.x - x, texCoord.y + y)).rgb;
+    vec3 k = getColor(m_Texture, vec2(texCoord.x + x, texCoord.y + y)).rgb;
+    vec3 l = getColor(m_Texture, vec2(texCoord.x - x, texCoord.y - y)).rgb;
+    vec3 m = getColor(m_Texture, vec2(texCoord.x + x, texCoord.y - y)).rgb;
+
+    // Apply weighted distribution:
+    // 0.5 + 0.125 + 0.125 + 0.125 + 0.125 = 1
+    // a,b,d,e * 0.125
+    // b,c,e,f * 0.125
+    // d,e,g,h * 0.125
+    // e,f,h,i * 0.125
+    // j,k,l,m * 0.5
+    // This shows 5 square areas that are being sampled. But some of them overlap,
+    // so to have an energy preserving downsample we need to make some adjustments.
+    // The weights are the distributed, so that the sum of j,k,l,m (e.g.)
+    // contribute 0.5 to the final color output. The code below is written
+    // to effectively yield this sum. We get:
+    // 0.125*5 + 0.03125*4 + 0.0625*4 = 1
+    vec3 downsample = e*0.125;
+    downsample += (a+c+g+i)*0.03125;
+    downsample += (b+d+f+h)*0.0625;
+    downsample += (j+k+l+m)*0.125;
+
+    gl_FragColor = vec4(downsample, 1.0);
+
+}

jme3-effects/src/main/resources/Common/MatDefs/Post/Downsample.j3md

@@ -0,0 +1,22 @@
+MaterialDef Downsample {
+
+    MaterialParameters {
+        Texture2D Texture
+        Vector2 TexelSize
+        Int BoundDrawBuffer
+        Int NumSamples
+    }
+
+    Technique {
+        VertexShader   GLSL300 GLSL150 GLSL100: Common/MatDefs/Post/Post.vert
+        FragmentShader GLSL300 GLSL150 GLSL100: Common/MatDefs/Post/Downsample.frag
+
+        WorldParameters {
+        }
+
+        Defines {
+            BOUND_DRAW_BUFFER: BoundDrawBuffer
+            RESOLVE_MS : NumSamples
+        }
+    }
+}

jme3-effects/src/main/resources/Common/MatDefs/Post/PBRBloomFinal.frag

@@ -0,0 +1,15 @@
+
+#import "Common/ShaderLib/GLSLCompat.glsllib"
+#import "Common/ShaderLib/MultiSample.glsllib"
+
+uniform COLORTEXTURE m_Texture;
+uniform sampler2D m_GlowMap;
+uniform float m_GlowFactor;
+varying vec2 texCoord;
+
+void main() {
+
+    gl_FragColor = mix(getColor(m_Texture, texCoord), texture2D(m_GlowMap, texCoord), m_GlowFactor);
+
+}
+

jme3-effects/src/main/resources/Common/MatDefs/Post/PBRBloomFinal.j3md

@@ -0,0 +1,23 @@
+MaterialDef PBRBloomFinal {
+
+    MaterialParameters {
+        Texture2D Texture
+        Texture2D GlowMap
+        Float GlowFactor : 0.05
+        Int BoundDrawBuffer
+        Int NumSamples
+    }
+
+    Technique {
+        VertexShader   GLSL300 GLSL150 GLSL100: Common/MatDefs/Post/Post.vert
+        FragmentShader GLSL300 GLSL150 GLSL100: Common/MatDefs/Post/PBRBloomFinal.frag
+
+        WorldParameters {
+        }
+
+        Defines {
+            BOUND_DRAW_BUFFER: BoundDrawBuffer
+            RESOLVE_MS : NumSamples
+        }
+    }
+}