GPU Particles с использованием Compute и Geometry шейдеров

struct Particle
{
    float3 Position;
    float3 Velocity;
};

StructuredBuffer<Particle> Particles : register(t0);

Texture2D<float> ParticleTexture : register(t1);
SamplerState ParticleSampler : register(s1);

cbuffer Params : register(b0)
{
	float4x4 ViewProjection;
	float4x4 Projection;
};

struct VertexInput
{
    uint VertexID : SV_VertexID;
};

struct GeometryInput
{
	float4 Position : SV_POSITION;
	float3 PositionTWS : TEXCOORD0;
	float2 Size : SIZE;
};

struct PixelInput
{
	float4 Position : SV_POSITION;
	float2 UV : TEXCOORD0;
	float3 PositionTWS : TEXCOORD1;
};

struct PixelOutput
{
    float4 Color : SV_TARGET0;
};

GeometryInput TriangleVS(VertexInput input)
{
	GeometryInput output = (GeometryInput)0;

	Particle particle = Particles[input.VertexID];

	output.Position = mul(float4(particle.Position, 1), ViewProjection);
	float size = 0.1;
	output.Size = size * float2(Projection[0][0], Projection[1][1]);
	float speedLength = length(particle.Velocity);
	//float magnitude = saturate(length(worldPosition.xyz) * 0.1);

	output.PositionTWS = float3(lerp(float3(0.1, 0.5, 1.0), float3(1.0, 0.5, 0.1), speedLength * 0.1));
 
	return output;
}

void FillQuadVertex(inout PixelInput data, in float2 NewXY, in float2 UV)
{
	data.Position.xy = NewXY;
	data.UV = UV;
}

[maxvertexcount(4)]
void TriangleGS( point GeometryInput input[1], inout TriangleStream<PixelInput> stream )
{
	PixelInput Out;
	Out.Position.zw = input[0].Position.zw;
    Out.PositionTWS = input[0].PositionTWS;

	FillQuadVertex(Out, input[0].Position.xy + float2(-1,-1) * input[0].Size, float2(0, 0)); stream.Append(Out);
	FillQuadVertex(Out, input[0].Position.xy + float2(-1, 1) * input[0].Size, float2(0, 1)); stream.Append(Out);
	FillQuadVertex(Out, input[0].Position.xy + float2( 1,-1) * input[0].Size, float2(1, 0)); stream.Append(Out);
	FillQuadVertex(Out, input[0].Position.xy + float2( 1, 1) * input[0].Size, float2(1, 1)); stream.Append(Out);

	stream.RestartStrip();
}

PixelOutput TrianglePS(PixelInput input)
{
	PixelOutput output = (PixelOutput)0;
	float particle = ParticleTexture.Sample(ParticleSampler, input.UV).x * 0.3;
	float3 speedColor = input.PositionTWS;
	output.Color = float4(speedColor * particle, 1);
	return output;
}

technique ParticleRender
{
	pass DefaultPass
	{
		Profile = 10.0;
		VertexShader = TriangleVS;
		GeometryShader = TriangleGS;
		PixelShader = TrianglePS;
	}
}