mixing gradients

zoneb/bin/data/shaders/particles/draw.frag

@@ -5,7 +5,10 @@ uniform sampler2DRect particles2;
 uniform sampler2DRect   u_depth;
 uniform sampler2DRect   u_world;
 uniform sampler2DRect   u_v4l2cam;
-uniform sampler2DRect   imageTexture;
+uniform sampler2DRect   warm1;
+uniform sampler2DRect   warm2;
+uniform sampler2DRect   cold1;
+uniform sampler2DRect   cold2;
 
 uniform vec3 uHottest0;
 uniform vec3 uHottest1;
@@ -17,15 +20,93 @@ in vec3 vPos;
 in float vTemperature;
 in float vAge;
 
+
+vec3 random3(vec3 c) {
+	float j = 4096.0*sin(dot(c,vec3(17.0, 59.4, 15.0)));
+	vec3 r;
+	r.z = fract(512.0*j);
+	j *= .125;
+	r.x = fract(512.0*j);
+	j *= .125;
+	r.y = fract(512.0*j);
+	return r-0.5;
+}
+
+/* skew constants for 3d simplex functions */
+const float F3 =  0.3333333;
+const float G3 =  0.1666667;
+
+/* 3d simplex noise */
+float simplex3d(vec3 p) {
+	 /* 1. find current tetrahedron T and it's four vertices */
+	 /* s, s+i1, s+i2, s+1.0 - absolute skewed (integer) coordinates of T vertices */
+	 /* x, x1, x2, x3 - unskewed coordinates of p relative to each of T vertices*/
+	 
+	 /* calculate s and x */
+	 vec3 s = floor(p + dot(p, vec3(F3)));
+	 vec3 x = p - s + dot(s, vec3(G3));
+	 
+	 /* calculate i1 and i2 */
+	 vec3 e = step(vec3(0.0), x - x.yzx);
+	 vec3 i1 = e*(1.0 - e.zxy);
+	 vec3 i2 = 1.0 - e.zxy*(1.0 - e);
+	 	
+	 /* x1, x2, x3 */
+	 vec3 x1 = x - i1 + G3;
+	 vec3 x2 = x - i2 + 2.0*G3;
+	 vec3 x3 = x - 1.0 + 3.0*G3;
+	 
+	 /* 2. find four surflets and store them in d */
+	 vec4 w, d;
+	 
+	 /* calculate surflet weights */
+	 w.x = dot(x, x);
+	 w.y = dot(x1, x1);
+	 w.z = dot(x2, x2);
+	 w.w = dot(x3, x3);
+	 
+	 /* w fades from 0.6 at the center of the surflet to 0.0 at the margin */
+	 w = max(0.6 - w, 0.0);
+	 
+	 /* calculate surflet components */
+	 d.x = dot(random3(s), x);
+	 d.y = dot(random3(s + i1), x1);
+	 d.z = dot(random3(s + i2), x2);
+	 d.w = dot(random3(s + 1.0), x3);
+	 
+	 /* multiply d by w^4 */
+	 w *= w;
+	 w *= w;
+	 d *= w;
+	 
+	 /* 3. return the sum of the four surflets */
+	 return dot(d, vec4(52.0));
+}
+
+/* const matrices for 3d rotation */
+const mat3 rot1 = mat3(-0.37, 0.36, 0.85,-0.14,-0.93, 0.34,0.92, 0.01,0.4);
+const mat3 rot2 = mat3(-0.55,-0.39, 0.74, 0.33,-0.91,-0.24,0.77, 0.12,0.63);
+const mat3 rot3 = mat3(-0.71, 0.52,-0.47,-0.08,-0.72,-0.68,-0.7,-0.45,0.56);
+
+/* directional artifacts can be reduced by rotating each octave */
+float simplex3d_fractal(vec3 m) {
+    return   0.5333333*simplex3d(m*rot1)
+			+0.2666667*simplex3d(2.0*m*rot2)
+			+0.1333333*simplex3d(4.0*m*rot3)
+			+0.0666667*simplex3d(8.0*m);
+}
+
 void main()
 {
-  vec3 remapedColor = texture(imageTexture, vec2(vTemperature*1600, 0.5)).xyz;
+  vec2 palette = vec2(vTemperature*3425, 0.5);
+  vec3 remapedColorW = texture(warm1, palette).xyz;
+  vec3 remapedColorC = texture(cold2, palette).xyz;
+  float d = 50;
+  float rate = smoothstep(500 - d, 500 + d, length(vPos.x - uHottest3d1.x) + simplex3d(vPos * vec3(0.001, 0.001, 0.1)) * 100);
+  vec3 remapedColor = mix(remapedColorW, remapedColorC, rate);
   float alpha = max(0, 1 - pow(vAge,4));
   
   vec4 color = vec4(remapedColor, alpha);
 
-  if(length(vPos.x - uHottest3d1.x) < 500) {
-    color = vec4(0,1,0,1);
-  }
   fragColor = color;
 }

zoneb/src/ofApp.cpp

@@ -109,7 +109,11 @@ void ofApp::setupParticles()
   particles.whateverImages.insert({"u_depth", kinectDevice.getDepthTex()});
   particles.whateverImages.insert({"u_world", kinectDevice.getDepthToWorldTex()});
   particles.whateverImages.insert({"u_v4l2cam", v4l2Tex});
-  particles.whateverImages.insert({"imageTexture", gradient.getTexture()});
+
+  for (auto i : gradients)
+  {
+    particles.whateverImages.insert({i.first, i.second.getTexture()});
+  }
 
   // listen for update event to set additonal update uniforms
   ofAddListener(particles.updateEvent, this, &ofApp::onParticlesUpdate);
@@ -148,8 +152,11 @@ void ofApp::setup()
   fbos.insert({"ofcam", ofFbo()});
   fbos.at("ofcam").allocate(ofGetWidth(), ofGetHeight(), GL_RGBA32F_ARB);
 
-  gradient.load("gradient.jpg");
-
+  for (auto s : gradientNames)
+  {
+    gradients.insert({s, ofFloatImage()});
+    gradients.at(s).load(s + ".png");
+  }
   setupParticles();
 }
 
@@ -281,7 +288,6 @@ void ofApp::drawMain()
   boundShader.setUniformTexture("u_depth", tex);
   boundShader.setUniformTexture("u_ofcam", fbos.at("ofcam"));
   boundShader.setUniformTexture("u_v4l2cam", v4l2Tex);
-  boundShader.setUniformTexture("u_gradient", gradient);
   boundShader.setUniform1i("u_init", 1);
   boundShader.render();
   boundShader.setUniform1i("u_init", 0);

zoneb/src/ofApp.h

@@ -50,13 +50,13 @@ private:
   ofxShaderFilter boundShader;
 
   std::map<string, ofFbo> fbos;
+  std::map<string, ofFloatImage> gradients;
+  std::vector<std::string> gradientNames {"warm1", "warm2", "cold1", "cold2"};
 
   ofxV4L2 v4l2Cam;
   ofTexture v4l2Tex;
   ofPixels v4l2Pixels;
 
-  ofFloatImage gradient;
-
   ofxGpuParticles particles;
 
   std::vector<std::vector<ofVec3f>> hotspots;