metaballs/Assets/Shaders/FalloffFunctionComputeShader.compute

#pragma kernel Calculate

struct Values {
	float edge0Val, edge1Val, edge2Val, edge3Val, edge4Val, edge5Val, edge6Val, edge7Val;
};

struct Positions {
	float3 edge0Pos, edge1Pos, edge2Pos, edge3Pos, edge4Pos, edge5Pos, edge6Pos, edge7Pos;
};

struct Ball {
	float radiusSq;
	float3 position;
};

StructuredBuffer<Positions> positions;
StructuredBuffer<Ball> metaballs;
RWStructuredBuffer<Values> outputBuffer;

int width;
int height;

int numMetaballs;

[numthreads(8,8,8)]
void Calculate(uint3 id : SV_DispatchThreadID)
{
	int pos = id.x + width * (id.y + height * id.z);

	outputBuffer[pos].edge0Val = 0;
	outputBuffer[pos].edge1Val = 0;
	outputBuffer[pos].edge2Val = 0;
	outputBuffer[pos].edge3Val = 0;
	outputBuffer[pos].edge4Val = 0;
	outputBuffer[pos].edge5Val = 0;
	outputBuffer[pos].edge6Val = 0;
	outputBuffer[pos].edge7Val = 0;

	for (int i = 0; i < numMetaballs; i++) {
		float3 dist = positions[pos].edge0Pos - metaballs[i].position;
		outputBuffer[pos].edge0Val += metaballs[i].radiusSq / (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);

		dist = positions[pos].edge1Pos - metaballs[i].position;
		outputBuffer[pos].edge1Val += metaballs[i].radiusSq / (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);

		dist = positions[pos].edge2Pos - metaballs[i].position;
		outputBuffer[pos].edge2Val += metaballs[i].radiusSq / (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);

		dist = positions[pos].edge3Pos - metaballs[i].position;
		outputBuffer[pos].edge3Val += metaballs[i].radiusSq / (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);

		dist = positions[pos].edge4Pos - metaballs[i].position;
		outputBuffer[pos].edge4Val += metaballs[i].radiusSq / (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);

		dist = positions[pos].edge5Pos - metaballs[i].position;
		outputBuffer[pos].edge5Val += metaballs[i].radiusSq / (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);

		dist = positions[pos].edge6Pos - metaballs[i].position;
		outputBuffer[pos].edge6Val += metaballs[i].radiusSq / (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);

		dist = positions[pos].edge7Pos - metaballs[i].position;
		outputBuffer[pos].edge7Val += metaballs[i].radiusSq / (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);
	}
}