Homework1 三维布料模拟

linyaodong · July 1, 2020, 2:02pm

cloth

源码地址

lyd405121/OpenClothPy/blob/master/cloth.py

import taichi as ti
ti.init(arch=ti.gpu)

#gui system using taichi-ggui:
#https://docs.taichi.graphics/zh-Hans/docs/lang/articles/misc/ggui
imgSize = 512


clothWid  = 4.0
clothHgt  = 4.0
clothResX = 31

num_triangles = clothResX  * clothResX * 2
indices       = ti.field(int, num_triangles * 3)
vertices      = ti.Vector.field(3, float, (clothResX+1)*(clothResX+1))

pos_pre    = ti.Vector.field(3, dtype=ti.f32, shape=(clothResX+1, clothResX+1))
pos        = ti.Vector.field(3, dtype=ti.f32, shape=(clothResX+1, clothResX+1))
vel        = ti.Vector.field(3, dtype=ti.f32, shape=(clothResX+1, clothResX+1))
F          = ti.Vector.field(3, dtype=ti.f32, shape=(clothResX+1, clothResX+1))

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linyaodong · July 1, 2020, 2:04pm

opencloth 源码地址

投影算法使用微软d3dx
https://docs.microsoft.com/enus/windows/win32/direct3d9/d3dxmatrixperspectiverh

画线算法用了milo yip大神的代码

github.com

miloyip/line/blob/master/line_bresenham.c

#include "svpng.inc"
#include <math.h>   // fmaxf(), sinf(), cosf()
#include <stdlib.h> // abs()
#include <string.h> // memset()
#define PI 3.14159265359f
#define W 512
#define H 512
static unsigned char img[W * H * 3];

void setpixel(int x, int y) {
    unsigned char* p = img + (y * W + x) * 3;
    p[0] = p[1] = p[2] = 0;
}

// Modified from  https://rosettacode.org/wiki/Bitmap/Bresenham%27s_line_algorithm#C
void bresenham(int x0, int y0, int x1, int y1) {
    int dx = abs(x1 - x0), sx = x0 < x1 ? 1 : -1;
    int dy = abs(y1 - y0), sy = y0 < y1 ? 1 : -1;
    int err = (dx > dy ? dx : -dy) / 2;

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linyaodong · July 1, 2020, 2:06pm

三种算法在不同弹簧系数下的最大时间步长

maxt

linyaodong · July 1, 2020, 2:07pm

三种算法的耗时
compute_time