godot/core/math/triangle_mesh.cpp
Kiri Jolly bac44ee19f Fixed false positives in the culling system.
This fixes numerous false positives coming out of the culling system.

AABB checks are now a full separating-axis check against the frustum, with the points of the frustum being compared to the planes of the box just as the points of the box were being compared to the planes of the frustum. This fixes large objects behind the camera not being culled correctly.

Some systems that used frustums that were (sometimes mistakenly?) unbounded on one or more side have been modified to be fully enclosed.
2020-04-28 17:14:06 -07:00

763 lines
18 KiB
C++

/*************************************************************************/
/* triangle_mesh.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/*************************************************************************/
#include "triangle_mesh.h"
#include "core/sort_array.h"
int TriangleMesh::_create_bvh(BVH *p_bvh, BVH **p_bb, int p_from, int p_size, int p_depth, int &max_depth, int &max_alloc) {
if (p_depth > max_depth) {
max_depth = p_depth;
}
if (p_size == 1) {
return p_bb[p_from] - p_bvh;
} else if (p_size == 0) {
return -1;
}
AABB aabb;
aabb = p_bb[p_from]->aabb;
for (int i = 1; i < p_size; i++) {
aabb.merge_with(p_bb[p_from + i]->aabb);
}
int li = aabb.get_longest_axis_index();
switch (li) {
case Vector3::AXIS_X: {
SortArray<BVH *, BVHCmpX> sort_x;
sort_x.nth_element(0, p_size, p_size / 2, &p_bb[p_from]);
//sort_x.sort(&p_bb[p_from],p_size);
} break;
case Vector3::AXIS_Y: {
SortArray<BVH *, BVHCmpY> sort_y;
sort_y.nth_element(0, p_size, p_size / 2, &p_bb[p_from]);
//sort_y.sort(&p_bb[p_from],p_size);
} break;
case Vector3::AXIS_Z: {
SortArray<BVH *, BVHCmpZ> sort_z;
sort_z.nth_element(0, p_size, p_size / 2, &p_bb[p_from]);
//sort_z.sort(&p_bb[p_from],p_size);
} break;
}
int left = _create_bvh(p_bvh, p_bb, p_from, p_size / 2, p_depth + 1, max_depth, max_alloc);
int right = _create_bvh(p_bvh, p_bb, p_from + p_size / 2, p_size - p_size / 2, p_depth + 1, max_depth, max_alloc);
int index = max_alloc++;
BVH *_new = &p_bvh[index];
_new->aabb = aabb;
_new->center = aabb.position + aabb.size * 0.5;
_new->face_index = -1;
_new->left = left;
_new->right = right;
return index;
}
void TriangleMesh::get_indices(PoolVector<int> *r_triangles_indices) const {
if (!valid)
return;
const int triangles_num = triangles.size();
// Parse vertices indices
PoolVector<Triangle>::Read triangles_read = triangles.read();
r_triangles_indices->resize(triangles_num * 3);
PoolVector<int>::Write r_indices_write = r_triangles_indices->write();
for (int i = 0; i < triangles_num; ++i) {
r_indices_write[3 * i + 0] = triangles_read[i].indices[0];
r_indices_write[3 * i + 1] = triangles_read[i].indices[1];
r_indices_write[3 * i + 2] = triangles_read[i].indices[2];
}
}
void TriangleMesh::create(const PoolVector<Vector3> &p_faces) {
valid = false;
int fc = p_faces.size();
ERR_FAIL_COND(!fc || ((fc % 3) != 0));
fc /= 3;
triangles.resize(fc);
bvh.resize(fc * 3); //will never be larger than this (todo make better)
PoolVector<BVH>::Write bw = bvh.write();
{
//create faces and indices and base bvh
//except for the Set for repeated triangles, everything
//goes in-place.
PoolVector<Vector3>::Read r = p_faces.read();
PoolVector<Triangle>::Write w = triangles.write();
Map<Vector3, int> db;
for (int i = 0; i < fc; i++) {
Triangle &f = w[i];
const Vector3 *v = &r[i * 3];
for (int j = 0; j < 3; j++) {
int vidx = -1;
Vector3 vs = v[j].snapped(Vector3(0.0001, 0.0001, 0.0001));
Map<Vector3, int>::Element *E = db.find(vs);
if (E) {
vidx = E->get();
} else {
vidx = db.size();
db[vs] = vidx;
}
f.indices[j] = vidx;
if (j == 0)
bw[i].aabb.position = vs;
else
bw[i].aabb.expand_to(vs);
}
f.normal = Face3(r[i * 3 + 0], r[i * 3 + 1], r[i * 3 + 2]).get_plane().get_normal();
bw[i].left = -1;
bw[i].right = -1;
bw[i].face_index = i;
bw[i].center = bw[i].aabb.position + bw[i].aabb.size * 0.5;
}
vertices.resize(db.size());
PoolVector<Vector3>::Write vw = vertices.write();
for (Map<Vector3, int>::Element *E = db.front(); E; E = E->next()) {
vw[E->get()] = E->key();
}
}
PoolVector<BVH *> bwptrs;
bwptrs.resize(fc);
PoolVector<BVH *>::Write bwp = bwptrs.write();
for (int i = 0; i < fc; i++) {
bwp[i] = &bw[i];
}
max_depth = 0;
int max_alloc = fc;
_create_bvh(bw.ptr(), bwp.ptr(), 0, fc, 1, max_depth, max_alloc);
bw.release(); //clearup
bvh.resize(max_alloc); //resize back
valid = true;
}
Vector3 TriangleMesh::get_area_normal(const AABB &p_aabb) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
int n_count = 0;
Vector3 n;
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
const Triangle *triangleptr = trianglesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool valid = b.aabb.intersects(p_aabb);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
n += s.normal;
n_count++;
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
if (n_count > 0)
n /= n_count;
return n;
}
bool TriangleMesh::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_point, Vector3 &r_normal) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
Vector3 n = (p_end - p_begin).normalized();
real_t d = 1e10;
bool inters = false;
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
const Triangle *triangleptr = trianglesr.ptr();
const Vector3 *vertexptr = verticesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool valid = b.aabb.intersects_segment(p_begin, p_end);
//bool valid = b.aabb.intersects(ray_aabb);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
Face3 f3(vertexptr[s.indices[0]], vertexptr[s.indices[1]], vertexptr[s.indices[2]]);
Vector3 res;
if (f3.intersects_segment(p_begin, p_end, &res)) {
real_t nd = n.dot(res);
if (nd < d) {
d = nd;
r_point = res;
r_normal = f3.get_plane().get_normal();
inters = true;
}
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
if (inters) {
if (n.dot(r_normal) > 0)
r_normal = -r_normal;
}
return inters;
}
bool TriangleMesh::intersect_ray(const Vector3 &p_begin, const Vector3 &p_dir, Vector3 &r_point, Vector3 &r_normal) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
Vector3 n = p_dir;
real_t d = 1e20;
bool inters = false;
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
const Triangle *triangleptr = trianglesr.ptr();
const Vector3 *vertexptr = verticesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool valid = b.aabb.intersects_ray(p_begin, p_dir);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
Face3 f3(vertexptr[s.indices[0]], vertexptr[s.indices[1]], vertexptr[s.indices[2]]);
Vector3 res;
if (f3.intersects_ray(p_begin, p_dir, &res)) {
real_t nd = n.dot(res);
if (nd < d) {
d = nd;
r_point = res;
r_normal = f3.get_plane().get_normal();
inters = true;
}
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
if (inters) {
if (n.dot(r_normal) > 0)
r_normal = -r_normal;
}
return inters;
}
bool TriangleMesh::intersect_convex_shape(const Plane *p_planes, int p_plane_count, const Vector3 *p_points, int p_point_count) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
//p_fully_inside = true;
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
const Triangle *triangleptr = trianglesr.ptr();
const Vector3 *vertexptr = verticesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool valid = b.aabb.intersects_convex_shape(p_planes, p_plane_count, p_points, p_point_count);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
for (int j = 0; j < 3; ++j) {
const Vector3 &point = vertexptr[s.indices[j]];
const Vector3 &next_point = vertexptr[s.indices[(j + 1) % 3]];
Vector3 res;
bool over = true;
for (int i = 0; i < p_plane_count; i++) {
const Plane &p = p_planes[i];
if (p.intersects_segment(point, next_point, &res)) {
bool inisde = true;
for (int k = 0; k < p_plane_count; k++) {
if (k == i) continue;
const Plane &pp = p_planes[k];
if (pp.is_point_over(res)) {
inisde = false;
break;
}
}
if (inisde) return true;
}
if (p.is_point_over(point)) {
over = false;
break;
}
}
if (over) return true;
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
return false;
}
bool TriangleMesh::inside_convex_shape(const Plane *p_planes, int p_plane_count, const Vector3 *p_points, int p_point_count, Vector3 p_scale) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
Transform scale(Basis().scaled(p_scale));
const Triangle *triangleptr = trianglesr.ptr();
const Vector3 *vertexptr = verticesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool intersects = scale.xform(b.aabb).intersects_convex_shape(p_planes, p_plane_count, p_points, p_point_count);
if (!intersects) return false;
bool inside = scale.xform(b.aabb).inside_convex_shape(p_planes, p_plane_count);
if (inside) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
for (int j = 0; j < 3; ++j) {
Vector3 point = scale.xform(vertexptr[s.indices[j]]);
for (int i = 0; i < p_plane_count; i++) {
const Plane &p = p_planes[i];
if (p.is_point_over(point)) return false;
}
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
return true;
}
bool TriangleMesh::is_valid() const {
return valid;
}
PoolVector<Face3> TriangleMesh::get_faces() const {
if (!valid)
return PoolVector<Face3>();
PoolVector<Face3> faces;
int ts = triangles.size();
faces.resize(triangles.size());
PoolVector<Face3>::Write w = faces.write();
PoolVector<Triangle>::Read r = triangles.read();
PoolVector<Vector3>::Read rv = vertices.read();
for (int i = 0; i < ts; i++) {
for (int j = 0; j < 3; j++) {
w[i].vertex[j] = rv[r[i].indices[j]];
}
}
w.release();
return faces;
}
TriangleMesh::TriangleMesh() {
valid = false;
max_depth = 0;
}