some diffuse added for funzies

shaders/agent_shader.gdshader

@@ -1,8 +1,17 @@
 shader_type canvas_item;
 
+// Snippets of code drawn from https://gist.github.com/Bleuje/1e497df4505ca24c39ab3930a95700b3
+
 uniform sampler2D sim_texture;
 
-void fragment() {
-	vec3 c = texture(sim_texture, UV).rgb;
-	COLOR = vec4(c, 1.0);
+float gn(in vec2 coordinate, in float seed){
+    return fract(tan(distance(coordinate*(seed+0.118446744073709551614), vec2(0.118446744073709551614, 0.314159265358979323846264)))*0.141421356237309504880169);
+}
+
+void fragment() {
+	vec3 orig = texture(sim_texture, UV).rgb;
+	float agent = orig.r;
+	float trail = orig.g;
+	
+	COLOR = vec4(agent, trail, orig.b, 1.0);
 }

shaders/dissolve.gdshader

@@ -5,7 +5,16 @@ uniform sampler2D sim_texture;
 uniform float decay_factor;
 
 void fragment() {
-	float c = texture(sim_texture, UV).r;
-	c = c * decay_factor;
-	COLOR = vec4(c, c, c, 1.0);
+	vec3 orig = texture(sim_texture, UV).rgb;
+	float trail = texture(sim_texture, UV).g;
+
+	float sum = 0.0;
+	for(int i=-1;i<=1;i++) {
+		for(int j=-1;j<=1;j++) {
+			sum += texture(sim_texture, UV).g;
+		}
+	}
+	trail = sum / 9.0;
+	trail = trail * decay_factor;
+	COLOR = vec4(orig.r, trail, orig.b, 1.0);
 }