第097封“情书”：浮生碌碌PDG For Design Work Pt. 4 - Distributed Grains Using PDG＜Entagma＞Houdini 2019

❖保留碰撞粒子❖

//--1 如果粒子碰撞次数小于1，删除粒子。

if(@hitnum<1){

    removepoint(0,@ptnum);

}

//--2 再设置一下粒子大小。

f@pscale = 0.005;

❖提取边缘粒子❖

//--1 临近点

int npt[] = nearpoints(0,v@P,0.05,96);

//--2 点数

int np = len(npt);

//--3 如果点数超过某一阈值，删除

if(np>72)

    removepoint(0,@ptnum);

❖映射随机粒子尺寸❖

f@pscale = 0.01*fit01(rand(@id),0.5,1.0);

❖popwrangle粒子尺寸❖

//--1 粒子年龄0~1

float u = f@age/f@life;

//--2 映射

float s = fit(u,0.0,0.1,0.0,1.0);

//--3 chramp更精确的驱动 ,再增加点随机性

f@pscale = chramp("ramp_scale",s)*chf("Amp")*fit01(rand(@id),0.25,1.0);