raymarching_direct_compute.compute

#pragma kernel CSMain

RWTexture2D<float4> render_texture;

float sphere (float3 p,float3 c,float r)
{
	return length (p-c)-r;
}

float map (float3 p)
{
	return sphere (p,float3(0.0,0.0,0.0),1.0);
}

float3 set_normal (float3 p)
{
	float3 x = float3 (0.01,0.00,0.00);
	float3 y = float3 (0.00,0.01,0.00);
	float3 z = float3 (0.00,0.00,0.01);
	return normalize(float3(map(p+x)-map(p-x), map(p+y)-map(p-y), map(p+z)-map(p-z))); 
}

float3 lighting ( float3 p)
{
	float3 AmbientLight = float3 (0.1,0.1,0.1);
	float3 LightDirection = normalize(float3(4.0,10.0,-10.0));
	float3 LightColor = float3 (1.0,1.0,1.0);
	float3 NormalDirection = set_normal(p);
	return  max ( dot(LightDirection, NormalDirection),0.0) * LightColor + AmbientLight;
}

float4 raymarch (float3 ro,float3 rd)
{
	for (int i=0;i<128;i++)
	{
		float t = map(ro);
		if (t<0.01) return float4(lighting(ro),1.0); else ro+=t*rd;
	}
	return float4(0.0,0.0,0.0,1.0);
}

[numthreads(8,8,1)]
void CSMain (uint2 id : SV_DispatchThreadID)
{  
	float2 resolution = float2 (1024,1024);  
	float2 coordinates = float2 (id.x,id.y);
	float2 p = (2.0*coordinates.xy-resolution.xy)/resolution.y;
	float3 ro = float3 (0.0,0.0,-10.0);
	float3 rd = normalize( float3(p.xy,2.0));
	render_texture[id] = raymarch( ro, rd );
}