本文整理汇总了C++中Bounds3f::SurfaceArea方法的典型用法代码示例。如果您正苦于以下问题:C++ Bounds3f::SurfaceArea方法的具体用法?C++ Bounds3f::SurfaceArea怎么用?C++ Bounds3f::SurfaceArea使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Bounds3f
的用法示例。
在下文中一共展示了Bounds3f::SurfaceArea方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: Assert
BVHBuildNode *BVHAccel::buildUpperSAH(MemoryArena &arena,
std::vector<BVHBuildNode *> &treeletRoots,
int start, int end,
int *totalNodes) const {
Assert(start < end);
int nNodes = end - start;
if (nNodes == 1) return treeletRoots[start];
(*totalNodes)++;
BVHBuildNode *node = arena.Alloc<BVHBuildNode>();
// Compute bounds of all nodes under this HLBVH node
Bounds3f bounds;
for (int i = start; i < end; ++i)
bounds = Union(bounds, treeletRoots[i]->bounds);
// Compute bound of HLBVH node centroids, choose split dimension _dim_
Bounds3f centroidBounds;
for (int i = start; i < end; ++i) {
Point3f centroid =
(treeletRoots[i]->bounds.pMin + treeletRoots[i]->bounds.pMax) *
0.5f;
centroidBounds = Union(centroidBounds, centroid);
}
int dim = centroidBounds.MaximumExtent();
// FIXME: if this hits, what do we need to do?
// Make sure the SAH split below does something... ?
Assert(centroidBounds.pMax[dim] != centroidBounds.pMin[dim]);
// Allocate _BucketInfo_ for SAH partition buckets
constexpr int nBuckets = 12;
struct BucketInfo {
int count = 0;
Bounds3f bounds;
};
BucketInfo buckets[nBuckets];
// Initialize _BucketInfo_ for HLBVH SAH partition buckets
for (int i = start; i < end; ++i) {
Float centroid = (treeletRoots[i]->bounds.pMin[dim] +
treeletRoots[i]->bounds.pMax[dim]) *
0.5f;
int b =
nBuckets * ((centroid - centroidBounds.pMin[dim]) /
(centroidBounds.pMax[dim] - centroidBounds.pMin[dim]));
if (b == nBuckets) b = nBuckets - 1;
Assert(b >= 0 && b < nBuckets);
buckets[b].count++;
buckets[b].bounds = Union(buckets[b].bounds, treeletRoots[i]->bounds);
}
// Compute costs for splitting after each bucket
Float cost[nBuckets - 1];
for (int i = 0; i < nBuckets - 1; ++i) {
Bounds3f b0, b1;
int count0 = 0, count1 = 0;
for (int j = 0; j <= i; ++j) {
b0 = Union(b0, buckets[j].bounds);
count0 += buckets[j].count;
}
for (int j = i + 1; j < nBuckets; ++j) {
b1 = Union(b1, buckets[j].bounds);
count1 += buckets[j].count;
}
cost[i] = .125f +
(count0 * b0.SurfaceArea() + count1 * b1.SurfaceArea()) /
bounds.SurfaceArea();
}
// Find bucket to split at that minimizes SAH metric
Float minCost = cost[0];
int minCostSplitBucket = 0;
for (int i = 1; i < nBuckets - 1; ++i) {
if (cost[i] < minCost) {
minCost = cost[i];
minCostSplitBucket = i;
}
}
// Split nodes and create interior HLBVH SAH node
BVHBuildNode **pmid = std::partition(
&treeletRoots[start], &treeletRoots[end - 1] + 1,
[=](const BVHBuildNode *node) {
Float centroid =
(node->bounds.pMin[dim] + node->bounds.pMax[dim]) * 0.5f;
int b = nBuckets *
((centroid - centroidBounds.pMin[dim]) /
(centroidBounds.pMax[dim] - centroidBounds.pMin[dim]));
if (b == nBuckets) b = nBuckets - 1;
Assert(b >= 0 && b < nBuckets);
return b <= minCostSplitBucket;
});
int mid = pmid - &treeletRoots[0];
Assert(mid > start && mid < end);
node->InitInterior(
dim, buildUpperSAH(arena, treeletRoots, start, mid, totalNodes),
buildUpperSAH(arena, treeletRoots, mid, end, totalNodes));
return node;
}