Arbitrary Colors

Assets/Scenes/SampleScene.unity

@@ -153,18 +153,18 @@ MonoBehaviour:
   depth: 8
   mesh: {fileID: 10207, guid: 0000000000000000e000000000000000, type: 0}
   material: {fileID: 2100000, guid: 8f3914ac4291e664ba60ae208ae66460, type: 2}
-  gradient:
+  gradientA:
     serializedVersion: 2
     key0: {r: 1, g: 1, b: 1, a: 1}
     key1: {r: 1, g: 0, b: 0, a: 1}
-    key2: {r: 0, g: 0, b: 0, a: 1}
+    key2: {r: 0, g: 0, b: 0, a: 0}
     key3: {r: 0, g: 0, b: 0, a: 0}
     key4: {r: 0, g: 0, b: 0, a: 0}
     key5: {r: 0, g: 0, b: 0, a: 0}
     key6: {r: 0, g: 0, b: 0, a: 0}
     key7: {r: 0, g: 0, b: 0, a: 0}
     ctime0: 0
-    ctime1: 39514
+    ctime1: 32768
     ctime2: 65535
     ctime3: 0
     ctime4: 0
@@ -173,7 +173,36 @@ MonoBehaviour:
     ctime7: 0
     atime0: 0
     atime1: 65535
-    atime2: 65535
+    atime2: 0
+    atime3: 0
+    atime4: 0
+    atime5: 0
+    atime6: 0
+    atime7: 0
+    m_Mode: 0
+    m_NumColorKeys: 3
+    m_NumAlphaKeys: 2
+  gradientB:
+    serializedVersion: 2
+    key0: {r: 0, g: 0, b: 1, a: 1}
+    key1: {r: 1, g: 1, b: 1, a: 1}
+    key2: {r: 1, g: 1, b: 0, a: 0}
+    key3: {r: 0, g: 0, b: 0, a: 0}
+    key4: {r: 0, g: 0, b: 0, a: 0}
+    key5: {r: 0, g: 0, b: 0, a: 0}
+    key6: {r: 0, g: 0, b: 0, a: 0}
+    key7: {r: 0, g: 0, b: 0, a: 0}
+    ctime0: 0
+    ctime1: 32768
+    ctime2: 65535
+    ctime3: 0
+    ctime4: 0
+    ctime5: 0
+    ctime6: 0
+    ctime7: 0
+    atime0: 0
+    atime1: 65535
+    atime2: 0
     atime3: 0
     atime4: 0
     atime5: 0

Assets/Script/Fractal.cs

@@ -3,6 +3,7 @@ using Unity.Collections;
 using Unity.Jobs;
 using Unity.Mathematics;
 using UnityEngine;
+using Random = UnityEngine.Random;
 
 using static Unity.Mathematics.math;
 using quaternion = Unity.Mathematics.quaternion;
@@ -62,7 +63,10 @@ public class Fractal : MonoBehaviour
     Material material = default;
 
     [SerializeField]
-    Gradient gradient = default;
+    Gradient gradientA = default;
+
+    [SerializeField]
+    Gradient gradientB = default;
 
     static float3[] directions =
     {
@@ -87,8 +91,12 @@ public class Fractal : MonoBehaviour
 
     ComputeBuffer[] matricesBuffers;
 
-    static readonly int colorId = Shader.PropertyToID("_Color");
+    Vector4[] sequenceNumbers;
+
+    static readonly int colorAId = Shader.PropertyToID("_ColorA");
+    static readonly int colorBId = Shader.PropertyToID("_ColorB");
     static readonly int matricesId = Shader.PropertyToID("_Matrices");
+    static readonly int sequenceNumbersId = Shader.PropertyToID("_SequenceNumbers");
 
     static MaterialPropertyBlock propertyBlock;
 
@@ -97,12 +105,14 @@ public class Fractal : MonoBehaviour
         parts = new NativeArray<FractalPart>[depth];
         matrices = new NativeArray<float3x4>[depth];
         matricesBuffers = new ComputeBuffer[depth];
+        sequenceNumbers = new Vector4[depth];
         int stride = 12 * 4;
         for (int i = 0, length = 1; i < parts.Length; i++, length *= 5)
         {
             parts[i] = new NativeArray<FractalPart>(length, Allocator.Persistent);
             matrices[i] = new NativeArray<float3x4>(length, Allocator.Persistent);
             matricesBuffers[i] = new ComputeBuffer(length, stride);
+            sequenceNumbers[i] = new Vector4(Random.value, Random.value);
         }
         
         parts[0][0] = CreatePart(0);
@@ -135,6 +145,7 @@ public class Fractal : MonoBehaviour
         parts = null;
         matrices = null;
         matricesBuffers = null;
+        sequenceNumbers = null;
     }
 
     void OnValidate()
@@ -181,8 +192,11 @@ public class Fractal : MonoBehaviour
         {
             ComputeBuffer buffer = matricesBuffers[i];
             buffer.SetData(matrices[i]);
-            propertyBlock.SetColor(colorId, gradient.Evaluate(i / (matricesBuffers.Length - 1f)));
+            float gradientInterpolator = i / (matricesBuffers.Length - 1f);
+            propertyBlock.SetColor(colorAId, gradientA.Evaluate(gradientInterpolator));
+            propertyBlock.SetColor(colorBId, gradientB.Evaluate(gradientInterpolator));
             propertyBlock.SetBuffer(matricesId, buffer);
+            propertyBlock.SetVector(sequenceNumbersId, sequenceNumbers[i]);
             Graphics.DrawMeshInstancedProcedural(mesh, 0, material, bounds, buffer.count, propertyBlock);
         }
     }

Assets/Script/PartGPU.hlsl

@@ -2,6 +2,21 @@
 	StructuredBuffer<float3x4> _Matrices;
 #endif
 
+float4 _ColorA, _ColorB;
+
+float2 _SequenceNumbers;
+
+float4 GetFractalColor () {
+	#if defined(UNITY_PROCEDURAL_INSTANCING_ENABLED)
+		return lerp(
+			_ColorA, _ColorB,
+			frac(unity_InstanceID * _SequenceNumbers.x + _SequenceNumbers.y)
+		);
+	#else
+		return _ColorA;
+	#endif
+}
+
 void ConfigureProcedural () {
 	#if defined(UNITY_PROCEDURAL_INSTANCING_ENABLED)
 		float3x4 m = _Matrices[unity_InstanceID];
@@ -12,10 +27,12 @@ void ConfigureProcedural () {
 	#endif
 }
 
-void ShaderGraphFunction_float (float3 In, out float3 Out) {
+void ShaderGraphFunction_float (float3 In, out float3 Out, out float4 FractalColor) {
 	Out = In;
+	FractalColor = GetFractalColor();
 }
 
-void ShaderGraphFunction_half (half3 In, out half3 Out) {
+void ShaderGraphFunction_half (half3 In, out half3 Out, out half4 FractalColor) {
 	Out = In;
+	FractalColor = GetFractalColor();
 }