File size: 18,753 Bytes
ddadf19 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 |
/*
Author: Yao Feng
Modified by Jianzhu Guo
functions that can not be optimazed by vertorization in python.
1. rasterization.(need process each triangle)
2. normal of each vertex.(use one-ring, need process each vertex)
3. write obj(seems that it can be verctorized? anyway, writing it in c++ is simple, so also add function here. --> however, why writting in c++ is still slow?)
*/
#include "rasterize.h"
/* Judge whether the Point is in the triangle
Method:
http://blackpawn.com/texts/pointinpoly/
Args:
Point: [x, y]
tri_points: three vertices(2d points) of a triangle. 2 coords x 3 vertices
Returns:
bool: true for in triangle
*/
bool is_point_in_tri(Point p, Point p0, Point p1, Point p2) {
// vectors
Point v0, v1, v2;
v0 = p2 - p0;
v1 = p1 - p0;
v2 = p - p0;
// dot products
float dot00 = v0.dot(v0); //v0.x * v0.x + v0.y * v0.y //np.dot(v0.T, v0)
float dot01 = v0.dot(v1); //v0.x * v1.x + v0.y * v1.y //np.dot(v0.T, v1)
float dot02 = v0.dot(v2); //v0.x * v2.x + v0.y * v2.y //np.dot(v0.T, v2)
float dot11 = v1.dot(v1); //v1.x * v1.x + v1.y * v1.y //np.dot(v1.T, v1)
float dot12 = v1.dot(v2); //v1.x * v2.x + v1.y * v2.y//np.dot(v1.T, v2)
// barycentric coordinates
float inverDeno;
if (dot00 * dot11 - dot01 * dot01 == 0)
inverDeno = 0;
else
inverDeno = 1 / (dot00 * dot11 - dot01 * dot01);
float u = (dot11 * dot02 - dot01 * dot12) * inverDeno;
float v = (dot00 * dot12 - dot01 * dot02) * inverDeno;
// check if Point in triangle
return (u >= 0) && (v >= 0) && (u + v < 1);
}
void get_point_weight(float *weight, Point p, Point p0, Point p1, Point p2) {
// vectors
Point v0, v1, v2;
v0 = p2 - p0;
v1 = p1 - p0;
v2 = p - p0;
// dot products
float dot00 = v0.dot(v0); //v0.x * v0.x + v0.y * v0.y //np.dot(v0.T, v0)
float dot01 = v0.dot(v1); //v0.x * v1.x + v0.y * v1.y //np.dot(v0.T, v1)
float dot02 = v0.dot(v2); //v0.x * v2.x + v0.y * v2.y //np.dot(v0.T, v2)
float dot11 = v1.dot(v1); //v1.x * v1.x + v1.y * v1.y //np.dot(v1.T, v1)
float dot12 = v1.dot(v2); //v1.x * v2.x + v1.y * v2.y//np.dot(v1.T, v2)
// barycentric coordinates
float inverDeno;
if (dot00 * dot11 - dot01 * dot01 == 0)
inverDeno = 0;
else
inverDeno = 1 / (dot00 * dot11 - dot01 * dot01);
float u = (dot11 * dot02 - dot01 * dot12) * inverDeno;
float v = (dot00 * dot12 - dot01 * dot02) * inverDeno;
// weight
weight[0] = 1 - u - v;
weight[1] = v;
weight[2] = u;
}
/*
* Get normals of triangles.
*/
void _get_tri_normal(float *tri_normal, float *vertices, int *triangles, int ntri, bool norm_flg) {
int tri_p0_ind, tri_p1_ind, tri_p2_ind;
float v1x, v1y, v1z, v2x, v2y, v2z;
for (int i = 0; i < ntri; i++) {
tri_p0_ind = triangles[3 * i];
tri_p1_ind = triangles[3 * i + 1];
tri_p2_ind = triangles[3 * i + 2];
// counter clockwise order
v1x = vertices[3 * tri_p1_ind] - vertices[3 * tri_p0_ind];
v1y = vertices[3 * tri_p1_ind + 1] - vertices[3 * tri_p0_ind + 1];
v1z = vertices[3 * tri_p1_ind + 2] - vertices[3 * tri_p0_ind + 2];
v2x = vertices[3 * tri_p2_ind] - vertices[3 * tri_p0_ind];
v2y = vertices[3 * tri_p2_ind + 1] - vertices[3 * tri_p0_ind + 1];
v2z = vertices[3 * tri_p2_ind + 2] - vertices[3 * tri_p0_ind + 2];
if (norm_flg) {
float c1 = v1y * v2z - v1z * v2y;
float c2 = v1z * v2x - v1x * v2z;
float c3 = v1x * v2y - v1y * v2x;
float det = sqrt(c1 * c1 + c2 * c2 + c3 * c3);
if (det <= 0) det = 1e-6;
tri_normal[3 * i] = c1 / det;
tri_normal[3 * i + 1] = c2 / det;
tri_normal[3 * i + 2] = c3 / det;
} else {
tri_normal[3 * i] = v1y * v2z - v1z * v2y;
tri_normal[3 * i + 1] = v1z * v2x - v1x * v2z;
tri_normal[3 * i + 2] = v1x * v2y - v1y * v2x;
}
}
}
/*
* Get normal vector of vertices using triangle normals
*/
void _get_ver_normal(float *ver_normal, float *tri_normal, int *triangles, int nver, int ntri) {
int tri_p0_ind, tri_p1_ind, tri_p2_ind;
for (int i = 0; i < ntri; i++) {
tri_p0_ind = triangles[3 * i];
tri_p1_ind = triangles[3 * i + 1];
tri_p2_ind = triangles[3 * i + 2];
for (int j = 0; j < 3; j++) {
ver_normal[3 * tri_p0_ind + j] += tri_normal[3 * i + j];
ver_normal[3 * tri_p1_ind + j] += tri_normal[3 * i + j];
ver_normal[3 * tri_p2_ind + j] += tri_normal[3 * i + j];
}
}
// normalizing
float nx, ny, nz, det;
for (int i = 0; i < nver; ++i) {
nx = ver_normal[3 * i];
ny = ver_normal[3 * i + 1];
nz = ver_normal[3 * i + 2];
det = sqrt(nx * nx + ny * ny + nz * nz);
if (det <= 0) det = 1e-6;
ver_normal[3 * i] = nx / det;
ver_normal[3 * i + 1] = ny / det;
ver_normal[3 * i + 2] = nz / det;
}
}
/*
* Directly get normal of vertices, which can be regraded as a combination of _get_tri_normal and _get_ver_normal
*/
void _get_normal(float *ver_normal, float *vertices, int *triangles, int nver, int ntri) {
int tri_p0_ind, tri_p1_ind, tri_p2_ind;
float v1x, v1y, v1z, v2x, v2y, v2z;
// get tri_normal
// float tri_normal[3 * ntri];
float *tri_normal;
tri_normal = new float[3 * ntri];
for (int i = 0; i < ntri; i++) {
tri_p0_ind = triangles[3 * i];
tri_p1_ind = triangles[3 * i + 1];
tri_p2_ind = triangles[3 * i + 2];
// counter clockwise order
v1x = vertices[3 * tri_p1_ind] - vertices[3 * tri_p0_ind];
v1y = vertices[3 * tri_p1_ind + 1] - vertices[3 * tri_p0_ind + 1];
v1z = vertices[3 * tri_p1_ind + 2] - vertices[3 * tri_p0_ind + 2];
v2x = vertices[3 * tri_p2_ind] - vertices[3 * tri_p0_ind];
v2y = vertices[3 * tri_p2_ind + 1] - vertices[3 * tri_p0_ind + 1];
v2z = vertices[3 * tri_p2_ind + 2] - vertices[3 * tri_p0_ind + 2];
tri_normal[3 * i] = v1y * v2z - v1z * v2y;
tri_normal[3 * i + 1] = v1z * v2x - v1x * v2z;
tri_normal[3 * i + 2] = v1x * v2y - v1y * v2x;
}
// get ver_normal
for (int i = 0; i < ntri; i++) {
tri_p0_ind = triangles[3 * i];
tri_p1_ind = triangles[3 * i + 1];
tri_p2_ind = triangles[3 * i + 2];
for (int j = 0; j < 3; j++) {
ver_normal[3 * tri_p0_ind + j] += tri_normal[3 * i + j];
ver_normal[3 * tri_p1_ind + j] += tri_normal[3 * i + j];
ver_normal[3 * tri_p2_ind + j] += tri_normal[3 * i + j];
}
}
// normalizing
float nx, ny, nz, det;
for (int i = 0; i < nver; ++i) {
nx = ver_normal[3 * i];
ny = ver_normal[3 * i + 1];
nz = ver_normal[3 * i + 2];
det = sqrt(nx * nx + ny * ny + nz * nz);
if (det <= 0) det = 1e-6;
ver_normal[3 * i] = nx / det;
ver_normal[3 * i + 1] = ny / det;
ver_normal[3 * i + 2] = nz / det;
}
delete[] tri_normal;
}
// rasterization by Z-Buffer with optimization
// Complexity: < ntri * h * w * c
void _rasterize(
unsigned char *image, float *vertices, int *triangles, float *colors, float *depth_buffer,
int ntri, int h, int w, int c, float alpha, bool reverse) {
int x, y, k;
int tri_p0_ind, tri_p1_ind, tri_p2_ind;
Point p0, p1, p2, p;
int x_min, x_max, y_min, y_max;
float p_depth, p0_depth, p1_depth, p2_depth;
float p_color, p0_color, p1_color, p2_color;
float weight[3];
for (int i = 0; i < ntri; i++) {
tri_p0_ind = triangles[3 * i];
tri_p1_ind = triangles[3 * i + 1];
tri_p2_ind = triangles[3 * i + 2];
p0.x = vertices[3 * tri_p0_ind];
p0.y = vertices[3 * tri_p0_ind + 1];
p0_depth = vertices[3 * tri_p0_ind + 2];
p1.x = vertices[3 * tri_p1_ind];
p1.y = vertices[3 * tri_p1_ind + 1];
p1_depth = vertices[3 * tri_p1_ind + 2];
p2.x = vertices[3 * tri_p2_ind];
p2.y = vertices[3 * tri_p2_ind + 1];
p2_depth = vertices[3 * tri_p2_ind + 2];
x_min = max((int) ceil(min(p0.x, min(p1.x, p2.x))), 0);
x_max = min((int) floor(max(p0.x, max(p1.x, p2.x))), w - 1);
y_min = max((int) ceil(min(p0.y, min(p1.y, p2.y))), 0);
y_max = min((int) floor(max(p0.y, max(p1.y, p2.y))), h - 1);
if (x_max < x_min || y_max < y_min) {
continue;
}
for (y = y_min; y <= y_max; y++) {
for (x = x_min; x <= x_max; x++) {
p.x = float(x);
p.y = float(y);
// call get_point_weight function once
get_point_weight(weight, p, p0, p1, p2);
// and judge is_point_in_tri by below line of code
if (weight[2] > 0 && weight[1] > 0 && weight[0] > 0) {
get_point_weight(weight, p, p0, p1, p2);
p_depth = weight[0] * p0_depth + weight[1] * p1_depth + weight[2] * p2_depth;
if ((p_depth > depth_buffer[y * w + x])) {
for (k = 0; k < c; k++) {
p0_color = colors[c * tri_p0_ind + k];
p1_color = colors[c * tri_p1_ind + k];
p2_color = colors[c * tri_p2_ind + k];
p_color = weight[0] * p0_color + weight[1] * p1_color + weight[2] * p2_color;
if (reverse) {
image[(h - 1 - y) * w * c + x * c + k] = (unsigned char) (
(1 - alpha) * image[(h - 1 - y) * w * c + x * c + k] + alpha * 255 * p_color);
// image[(h - 1 - y) * w * c + x * c + k] = (unsigned char) (255 * p_color);
} else {
image[y * w * c + x * c + k] = (unsigned char) (
(1 - alpha) * image[y * w * c + x * c + k] + alpha * 255 * p_color);
// image[y * w * c + x * c + k] = (unsigned char) (255 * p_color);
}
}
depth_buffer[y * w + x] = p_depth;
}
}
}
}
}
}
void _rasterize_triangles(
float *vertices, int *triangles, float *depth_buffer, int *triangle_buffer, float *barycentric_weight,
int ntri, int h, int w) {
int i;
int x, y, k;
int tri_p0_ind, tri_p1_ind, tri_p2_ind;
Point p0, p1, p2, p;
int x_min, x_max, y_min, y_max;
float p_depth, p0_depth, p1_depth, p2_depth;
float weight[3];
for (i = 0; i < ntri; i++) {
tri_p0_ind = triangles[3 * i];
tri_p1_ind = triangles[3 * i + 1];
tri_p2_ind = triangles[3 * i + 2];
p0.x = vertices[3 * tri_p0_ind];
p0.y = vertices[3 * tri_p0_ind + 1];
p0_depth = vertices[3 * tri_p0_ind + 2];
p1.x = vertices[3 * tri_p1_ind];
p1.y = vertices[3 * tri_p1_ind + 1];
p1_depth = vertices[3 * tri_p1_ind + 2];
p2.x = vertices[3 * tri_p2_ind];
p2.y = vertices[3 * tri_p2_ind + 1];
p2_depth = vertices[3 * tri_p2_ind + 2];
x_min = max((int) ceil(min(p0.x, min(p1.x, p2.x))), 0);
x_max = min((int) floor(max(p0.x, max(p1.x, p2.x))), w - 1);
y_min = max((int) ceil(min(p0.y, min(p1.y, p2.y))), 0);
y_max = min((int) floor(max(p0.y, max(p1.y, p2.y))), h - 1);
if (x_max < x_min || y_max < y_min) {
continue;
}
for (y = y_min; y <= y_max; y++) //h
{
for (x = x_min; x <= x_max; x++) //w
{
p.x = x;
p.y = y;
// if (p.x < 2 || p.x > w - 3 || p.y < 2 || p.y > h - 3 || is_point_in_tri(p, p0, p1, p2)) {
if (is_point_in_tri(p, p0, p1, p2)) {
get_point_weight(weight, p, p0, p1, p2);
p_depth = weight[0] * p0_depth + weight[1] * p1_depth + weight[2] * p2_depth;
if ((p_depth > depth_buffer[y * w + x])) {
depth_buffer[y * w + x] = p_depth;
triangle_buffer[y * w + x] = i;
for (k = 0; k < 3; k++) {
barycentric_weight[y * w * 3 + x * 3 + k] = weight[k];
}
}
}
}
}
}
}
// Depth-Buffer 算法
// https://blog.csdn.net/Jurbo/article/details/75007260
void _render_texture_core(
float *image, float *vertices, int *triangles,
float *texture, float *tex_coords, int *tex_triangles,
float *depth_buffer,
int nver, int tex_nver, int ntri,
int h, int w, int c,
int tex_h, int tex_w, int tex_c,
int mapping_type) {
int i;
int x, y, k;
int tri_p0_ind, tri_p1_ind, tri_p2_ind;
int tex_tri_p0_ind, tex_tri_p1_ind, tex_tri_p2_ind;
Point p0, p1, p2, p;
Point tex_p0, tex_p1, tex_p2, tex_p;
int x_min, x_max, y_min, y_max;
float weight[3];
float p_depth, p0_depth, p1_depth, p2_depth;
float xd, yd;
float ul, ur, dl, dr;
for (i = 0; i < ntri; i++) {
// mesh
tri_p0_ind = triangles[3 * i];
tri_p1_ind = triangles[3 * i + 1];
tri_p2_ind = triangles[3 * i + 2];
p0.x = vertices[3 * tri_p0_ind];
p0.y = vertices[3 * tri_p0_ind + 1];
p0_depth = vertices[3 * tri_p0_ind + 2];
p1.x = vertices[3 * tri_p1_ind];
p1.y = vertices[3 * tri_p1_ind + 1];
p1_depth = vertices[3 * tri_p1_ind + 2];
p2.x = vertices[3 * tri_p2_ind];
p2.y = vertices[3 * tri_p2_ind + 1];
p2_depth = vertices[3 * tri_p2_ind + 2];
// texture
tex_tri_p0_ind = tex_triangles[3 * i];
tex_tri_p1_ind = tex_triangles[3 * i + 1];
tex_tri_p2_ind = tex_triangles[3 * i + 2];
tex_p0.x = tex_coords[3 * tex_tri_p0_ind];
tex_p0.y = tex_coords[3 * tri_p0_ind + 1];
tex_p1.x = tex_coords[3 * tex_tri_p1_ind];
tex_p1.y = tex_coords[3 * tri_p1_ind + 1];
tex_p2.x = tex_coords[3 * tex_tri_p2_ind];
tex_p2.y = tex_coords[3 * tri_p2_ind + 1];
x_min = max((int) ceil(min(p0.x, min(p1.x, p2.x))), 0);
x_max = min((int) floor(max(p0.x, max(p1.x, p2.x))), w - 1);
y_min = max((int) ceil(min(p0.y, min(p1.y, p2.y))), 0);
y_max = min((int) floor(max(p0.y, max(p1.y, p2.y))), h - 1);
if (x_max < x_min || y_max < y_min) {
continue;
}
for (y = y_min; y <= y_max; y++) //h
{
for (x = x_min; x <= x_max; x++) //w
{
p.x = x;
p.y = y;
if (p.x < 2 || p.x > w - 3 || p.y < 2 || p.y > h - 3 || is_point_in_tri(p, p0, p1, p2)) {
get_point_weight(weight, p, p0, p1, p2);
p_depth = weight[0] * p0_depth + weight[1] * p1_depth + weight[2] * p2_depth;
if ((p_depth > depth_buffer[y * w + x])) {
// -- color from texture
// cal weight in mesh tri
get_point_weight(weight, p, p0, p1, p2);
// cal coord in texture
tex_p = tex_p0 * weight[0] + tex_p1 * weight[1] + tex_p2 * weight[2];
tex_p.x = max(min(tex_p.x, float(tex_w - 1)), float(0));
tex_p.y = max(min(tex_p.y, float(tex_h - 1)), float(0));
yd = tex_p.y - floor(tex_p.y);
xd = tex_p.x - floor(tex_p.x);
for (k = 0; k < c; k++) {
if (mapping_type == 0)// nearest
{
image[y * w * c + x * c + k] = texture[int(round(tex_p.y)) * tex_w * tex_c +
int(round(tex_p.x)) * tex_c + k];
} else//bilinear interp
{
ul = texture[(int) floor(tex_p.y) * tex_w * tex_c + (int) floor(tex_p.x) * tex_c + k];
ur = texture[(int) floor(tex_p.y) * tex_w * tex_c + (int) ceil(tex_p.x) * tex_c + k];
dl = texture[(int) ceil(tex_p.y) * tex_w * tex_c + (int) floor(tex_p.x) * tex_c + k];
dr = texture[(int) ceil(tex_p.y) * tex_w * tex_c + (int) ceil(tex_p.x) * tex_c + k];
image[y * w * c + x * c + k] =
ul * (1 - xd) * (1 - yd) + ur * xd * (1 - yd) + dl * (1 - xd) * yd +
dr * xd * yd;
}
}
depth_buffer[y * w + x] = p_depth;
}
}
}
}
}
}
// ------------------------------------------------- write
// obj write
// Ref: https://github.com/patrikhuber/eos/blob/master/include/eos/core/Mesh.hpp
void _write_obj_with_colors_texture(string filename, string mtl_name,
float *vertices, int *triangles, float *colors, float *uv_coords,
int nver, int ntri, int ntexver) {
int i;
ofstream obj_file(filename);
// first line of the obj file: the mtl name
obj_file << "mtllib " << mtl_name << endl;
// write vertices
for (i = 0; i < nver; ++i) {
obj_file << "v " << vertices[3 * i] << " " << vertices[3 * i + 1] << " " << vertices[3 * i + 2] << colors[3 * i]
<< " " << colors[3 * i + 1] << " " << colors[3 * i + 2] << endl;
}
// write uv coordinates
for (i = 0; i < ntexver; ++i) {
//obj_file << "vt " << uv_coords[2*i] << " " << (1 - uv_coords[2*i + 1]) << endl;
obj_file << "vt " << uv_coords[2 * i] << " " << uv_coords[2 * i + 1] << endl;
}
obj_file << "usemtl FaceTexture" << endl;
// write triangles
for (i = 0; i < ntri; ++i) {
// obj_file << "f " << triangles[3*i] << "/" << triangles[3*i] << " " << triangles[3*i + 1] << "/" << triangles[3*i + 1] << " " << triangles[3*i + 2] << "/" << triangles[3*i + 2] << endl;
obj_file << "f " << triangles[3 * i + 2] << "/" << triangles[3 * i + 2] << " " << triangles[3 * i + 1] << "/"
<< triangles[3 * i + 1] << " " << triangles[3 * i] << "/" << triangles[3 * i] << endl;
}
} |