Initial Commit

Assets/Scripts/DeltaHoone/Weather_System/Grass/GenerateGrass/FindPointsCompute.compute

@@ -0,0 +1,54 @@
+#pragma kernel ConvertTrianglesToDotsKernel
+
+struct TriangleInput {
+	float3 p1;
+	float3 p2;
+	float3 p3;
+	};
+
+StructuredBuffer<TriangleInput> triangles;
+
+RWStructuredBuffer<float3> positionOutputs;
+
+float maxDotAmount = 0.225;
+
+float seed = 1.32523252;
+
+int pointCountPerTriangle = 10;
+float pointsPerUnit = 1;
+
+float rand(float3 co){
+    return (frac(sin(dot(co ,float3(12.9898,78.233,45.5432))) * 43758.5453));
+    }
+
+float triangleArea (float3 a, float3 b, float3 c) {
+	//for simplicitys sake ignoring the y dimension and finding area of 2D triangle
+	return (a.x*(b.z-c.z) + b.x*(c.z-a.z) + c.x*(a.z-b.z))/2.0;
+	}
+
+float3 randomPointOnTriangle (float3 a, float3 b, float3 c, float index) {
+	float r1 = rand(index*b*seed);
+	float r0 = r1 + rand(index*c*seed) * (1-r1);//bigger
+	return float3(r1 * a.x + (r0-r1)*b.x + (1-r0)*c.x,
+				  r1 * a.y + (r0-r1)*b.y + (1-r0)*c.y,
+				  r1 * a.z + (r0-r1)*b.z + (1-r0)*c.z
+				  );
+	}
+
+[numthreads(16,1,1)]
+void ConvertTrianglesToDotsKernel (uint3 id : SV_DispatchThreadID)
+{
+    TriangleInput tri = triangles[id.x];
+    int startIndex = id.x*pointCountPerTriangle;
+    //based on triangle size get point amount
+    float points = min(triangleArea(tri.p1,tri.p2,tri.p3)*pointsPerUnit,pointCountPerTriangle);
+    for (int i = 0; i < pointCountPerTriangle; ++i) {
+    	if(i < points) {
+    		positionOutputs[startIndex + i] = randomPointOnTriangle(tri.p1,tri.p2,tri.p3, saturate((float)i/(float)points) );//tri.p1 * saturate(1 - (float)i/(float)points) + tri.p2 * saturate((float)i/(float)points);
+    		}
+    	else {
+    		positionOutputs[startIndex + i] = float3(0,0,0);
+    		}
+    	
+    	}
+}