compute_pres_visc.cg

来自「游戏编程精粹６第中关于粒子的实时流体仿真系统,对入门的游戏开发者很有帮助．」· CG 代码 · 共 34 行

#include "sph.cg"
void main(float2 tc0 : TEXCOORD0, // pair index
		  uniform samplerRECT attr_rect      : TEXUNIT0,  // attributes of particles
		  uniform samplerRECT neighbour_rect : TEXUNIT1,  // neighbour list
		  uniform float grad_spiky_coef,
		  uniform float lap_vis_coef,
		  //uniform float mass,
		  //uniform float viscosity,
		  out float3 result : COLOR // acceleration
		  )
{
	float m = MASS;
	float h = SMOOTHING_LENGTH;
	float mu = VISCOSITY;
	float2 texel = f2texRECT(neighbour_rect, tc0);
	float index = texel.x;
	float nindex = texel.y;

	float3 pos_i = f3texRECT(attr_rect, float2(index, GPU_ATTR_POS));
	float3 v_i = f3texRECT(attr_rect, float2(index, GPU_ATTR_VEL));
	float2 dp_i = f2texRECT(attr_rect, float2(index, GPU_ATTR_DP));

	float3 pos_j = f3texRECT(attr_rect, float2(nindex, GPU_ATTR_POS));
	float3 v_j = f3texRECT(attr_rect, float2(nindex, GPU_ATTR_VEL));
	float2 dp_j = f2texRECT(attr_rect, float2(nindex, GPU_ATTR_DP));

	float r = distance(pos_i, pos_j);
	float h_r = h - r;
	if (h_r > 0.0)
		result = m*h_r*dp_i.x*dp_j.x*(-0.5*(pos_i + pos_j)*grad_spiky_coef*h_r/r + (v_j - v_i)*mu*lap_vis_coef);
		//result = 45*m/(PI*pow(h, 6))*h_r*((dp_i.y + dp_j.y)*0.5*h_r*(pos_i - pos_j)/r + mu*(v_j - v_i))*dp_j.x*dp_i.x;
//		result = 45*m/(PI*h*h*h*h*h*h)*h_r*((dp_i.y + dp_j.y)*0.5*h_r*(pos_i - pos_j)/r + mu*(v_j - v_i))*dp_j.x*dp_i.x;
	else result = float3(0, 0, 0);
}