From 0df8984126b0c9a440fcb33ccb8580c268b9c76c Mon Sep 17 00:00:00 2001
From: Lukas Werner <lks.werner@fau.de>
Date: Thu, 8 Mar 2018 21:35:55 +0100
Subject: [PATCH] Added early cutoff for intersection testing in hashgrids
---
src/pe/ccd/HashGrids.h | 60 +++++++++++++++++++++++++++++++-----------
1 file changed, 45 insertions(+), 15 deletions(-)
diff --git a/src/pe/ccd/HashGrids.h b/src/pe/ccd/HashGrids.h
index e6fd5cdef..14dc612ca 100644
--- a/src/pe/ccd/HashGrids.h
+++ b/src/pe/ccd/HashGrids.h
@@ -527,13 +527,10 @@ const BodyID HashGrids::HashGrid::getBodyIntersectionForBlockCell(const Vector3<
real_t x = (real_c(blockCell[0]) + real_t(0.5)) * cellSpan_;
real_t y = (real_c(blockCell[1]) + real_t(0.5)) * cellSpan_;
real_t z = (real_c(blockCell[2]) + real_t(0.5)) * cellSpan_;
-
+
// hash of cell in the hashgrid
size_t cellHash = hashPoint(x, y, z);
- //WALBERLA_LOG_INFO("cell " << cellHash);
- //WALBERLA_LOG_INFO(" normal axis: " << int(cellNormalAxis) << ", dir: " << int(cellNormalDir));
-
const Cell& centerCell = cell_[cellHash];
std::vector<offset_t> relevantNeighborIndices;
@@ -582,7 +579,6 @@ const BodyID HashGrids::HashGrid::getBodyIntersectionForBlockCell(const Vector3<
body = cellBody;
t_closest = t_local;
n_closest = n_local;
- //WALBERLA_LOG_INFO(" found body " << body->getID() << " in " << neighborIndex << " (" << (int(cellHash)+centerCell.neighborOffset_[neighborIndex]) << ")");
}
}
}
@@ -617,10 +613,9 @@ BodyID HashGrids::HashGrid::getRayIntersectingBody(const raytracing::Ray& ray, c
int32_t blockYCellCountMax = int32_c(std::ceil(blockAABB.yMax() * inverseCellSpan_)) + 1;
int32_t blockZCellCountMin = int32_c(blockAABB.zMin() * inverseCellSpan_) - 1;
int32_t blockZCellCountMax = int32_c(std::ceil(blockAABB.zMax() * inverseCellSpan_)) + 1;
-
- //WALBERLA_LOG_INFO("cellspan: " << cellSpan_ << " lims: " << blockXCellCountMin << " " << blockXCellCountMax);
Vec3 firstPoint;
+ real_t tRayOriginToGrid = 0;
if (blockAABB.contains(ray.getOrigin(), cellSpan_)) {
firstPoint = ray.getOrigin();
} else {
@@ -629,8 +624,8 @@ BodyID HashGrids::HashGrid::getRayIntersectingBody(const raytracing::Ray& ray, c
if (intersects(blockAABB, ray, t_start, cellSpan_, &firstPointNormal)) {
firstPoint = ray.getOrigin() + ray.getDirection()*t_start;
firstPoint -= firstPointNormal * (cellSpan_/real_t(2));
+ tRayOriginToGrid = (ray.getOrigin() - firstPoint).length();
} else {
- //WALBERLA_LOG_INFO("ray does not intersect block")
return NULL;
}
}
@@ -647,10 +642,12 @@ BodyID HashGrids::HashGrid::getRayIntersectingBody(const raytracing::Ray& ray, c
(stepY >= 0) ? (firstCell[1]+1)*cellSpan_-firstPoint[1] : firstPoint[1]-firstCell[1]*cellSpan_,
(stepZ >= 0) ? (firstCell[2]+1)*cellSpan_-firstPoint[2] : firstPoint[2]-firstCell[2]*cellSpan_);
+ // tMax: distance along the ray to the next cell change in the axis direction
real_t tMaxX = (ray.xDir() != 0) ? std::abs(near[0]*ray.xInvDir()) : inf;
real_t tMaxY = (ray.yDir() != 0) ? std::abs(near[1]*ray.yInvDir()) : inf;
real_t tMaxZ = (ray.zDir() != 0) ? std::abs(near[2]*ray.zInvDir()) : inf;
+ // tDelta: how far along the ray must be moved to encounter a new cell in the specified axis direction
real_t tDeltaX = (ray.xDir() != 0) ? std::abs(cellSpan_*ray.xInvDir()) : inf;
real_t tDeltaY = (ray.yDir() != 0) ? std::abs(cellSpan_*ray.yInvDir()) : inf;
real_t tDeltaZ = (ray.zDir() != 0) ? std::abs(cellSpan_*ray.zInvDir()) : inf;
@@ -674,9 +671,17 @@ BodyID HashGrids::HashGrid::getRayIntersectingBody(const raytracing::Ray& ray, c
int8_t blockCellNormalAxis;
int8_t blockCellNormalDir;
+ static int earlyCutoffs = 0;
+
while (true) {
if (tMaxX < tMaxY) {
if (tMaxX < tMaxZ) {
+#if !defined(HASHGRIDS_DISABLE_EARLY_CUTOFF)
+ if (tRayOriginToGrid+tMaxX-tDeltaX > t_closest) {
+ earlyCutoffs++;
+ break;
+ }
+#endif
tMaxX += tDeltaX;
currentCell[0] += stepX;
blockCellNormalAxis = 0;
@@ -685,6 +690,12 @@ BodyID HashGrids::HashGrid::getRayIntersectingBody(const raytracing::Ray& ray, c
break;
}
} else {
+#if !defined(HASHGRIDS_DISABLE_EARLY_CUTOFF)
+ if (tRayOriginToGrid+tMaxZ-tDeltaZ > t_closest) {
+ earlyCutoffs++;
+ break;
+ }
+#endif
tMaxZ += tDeltaZ;
currentCell[2] += stepZ;
blockCellNormalAxis = 2;
@@ -695,6 +706,12 @@ BodyID HashGrids::HashGrid::getRayIntersectingBody(const raytracing::Ray& ray, c
}
} else {
if (tMaxY < tMaxZ) {
+#if !defined(HASHGRIDS_DISABLE_EARLY_CUTOFF)
+ if (tRayOriginToGrid+tMaxY-tDeltaY > t_closest) {
+ earlyCutoffs++;
+ break;
+ }
+#endif
tMaxY += tDeltaY;
currentCell[1] += stepY;
blockCellNormalAxis = 1;
@@ -703,6 +720,12 @@ BodyID HashGrids::HashGrid::getRayIntersectingBody(const raytracing::Ray& ray, c
break;
}
} else {
+#if !defined(HASHGRIDS_DISABLE_EARLY_CUTOFF)
+ if (tRayOriginToGrid+tMaxZ-tDeltaZ > t_closest) {
+ earlyCutoffs++;
+ break;
+ }
+#endif
tMaxZ += tDeltaZ;
currentCell[2] += stepZ;
blockCellNormalAxis = 2;
@@ -745,13 +768,6 @@ BodyID HashGrids::getClosestBodyIntersectingWithRay(const raytracing::Ray& ray,
real_t t_local = inf;
Vec3 n_local;
- for(auto grid: gridList_) {
- body_local = grid->getRayIntersectingBody<BodyTuple>(ray, blockAABB, t_closest, n_closest);
- if (body_local != NULL){
- body_closest = body_local;
- }
- }
-
raytracing::IntersectsFunctor intersectsFunc(ray, t_local, n_local);
for(auto body: nonGridBodies_) {
bool intersects = SingleCast<BodyTuple, raytracing::IntersectsFunctor, bool>::execute(body, intersectsFunc);
@@ -762,6 +778,20 @@ BodyID HashGrids::getClosestBodyIntersectingWithRay(const raytracing::Ray& ray,
}
}
+ for (auto gridIt = gridList_.rbegin(); gridIt != gridList_.rend(); ++gridIt) {
+ body_local = (*gridIt)->getRayIntersectingBody<BodyTuple>(ray, blockAABB, t_closest, n_closest);
+ if (body_local != NULL){
+ body_closest = body_local;
+ }
+ }
+
+ /*for(auto grid: gridList_) {
+ body_local = grid->getRayIntersectingBody<BodyTuple>(ray, blockAABB, t_closest, n_closest);
+ if (body_local != NULL){
+ body_closest = body_local;
+ }
+ }*/
+
t = t_closest;
n = n_closest;
--
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