compute_acc_vis.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 37 行

#include "kernel.cg"
#include "sph.cg"

void main(fixed2 sn_coord : TEXCOORD0,
		  /**
		  y  : subject particle index
		  xy : neighbour particle index
		  **/
		  uniform samplerRECT attr_rect      : TEXUNIT0,
		  uniform samplerRECT neighbour_rect : TEXUNIT1,
		  out float3 result : COLOR // acceleration
		  )
{
	float h = SMOOTHING_LENGTH;
	float m = MASS;
	float mu = VISCOSITY;
	
	float neighbour_index = f1texRECT(neighbour_rect, sn_coord);

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

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

	float r = distance(pos_i, pos_j);

	float h_r = h - r;

//	h_r = max(h_r, 0.0);

	if (h_r > 0.0)
		result = 15*m/(PI*h*h*h*h*h*h)*h_r*((dp_i.y + dp_j.y)*0.5*h_r*h_r*(pos_i - pos_j) + 3*mu*(v_j - v_i))*dp_j.x;///dp_j.x;
	else result = 0.0;
}