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// This code contains NVIDIA Confidential Information and is disclosed to you
// under a form of NVIDIA software license agreement provided separately to you.
//
// Notice
// NVIDIA Corporation and its licensors retain all intellectual property and
// proprietary rights in and to this software and related documentation and
// any modifications thereto. Any use, reproduction, disclosure, or
// distribution of this software and related documentation without an express
// license agreement from NVIDIA Corporation is strictly prohibited.
//
// ALL NVIDIA DESIGN SPECIFICATIONS, CODE ARE PROVIDED "AS IS.". NVIDIA MAKES
// NO WARRANTIES, EXPRESSED, IMPLIED, STATUTORY, OR OTHERWISE WITH RESPECT TO
// THE MATERIALS, AND EXPRESSLY DISCLAIMS ALL IMPLIED WARRANTIES OF NONINFRINGEMENT,
// MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE.
//
// Information and code furnished is believed to be accurate and reliable.
// However, NVIDIA Corporation assumes no responsibility for the consequences of use of such
// information or for any infringement of patents or other rights of third parties that may
// result from its use. No license is granted by implication or otherwise under any patent
// or patent rights of NVIDIA Corporation. Details are subject to change without notice.
// This code supersedes and replaces all information previously supplied.
// NVIDIA Corporation products are not authorized for use as critical
// components in life support devices or systems without express written approval of
// NVIDIA Corporation.
//
// Copyright (c) 2008-2018 NVIDIA Corporation. All rights reserved.
// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.
#include "foundation/PxBounds3.h"
#include "GuSweepTriangleUtils.h"
#include "GuDistancePointTriangle.h"
#include "GuVecTriangle.h"
#include "GuVecBox.h"
#include "GuSweepBoxTriangle_FeatureBased.h"
#include "GuInternal.h"
#include "GuGJK.h"
using namespace physx;
using namespace Gu;
using namespace physx::shdfnd::aos;
#define GU_SAFE_DISTANCE_FOR_NORMAL_COMPUTATION 0.1f
void Gu::computeSphereTriImpactData(PxVec3& hit, PxVec3& normal, const PxVec3& center, const PxVec3& dir, float t, const PxTriangle& tri)
{
const PxVec3 newSphereCenter = center + dir*t;
// We need the impact point, not computed by the new code
PxReal u_unused, v_unused;
const PxVec3 localHit = closestPtPointTriangle(newSphereCenter, tri.verts[0], tri.verts[1], tri.verts[2], u_unused, v_unused);
PX_UNUSED(u_unused);
PX_UNUSED(v_unused);
// This is responsible for the cap-vs-box stuck while jumping. However it's needed to slide on box corners!
// PT: this one is also dubious since the sphere/capsule center can be far away from the hit point when the radius is big!
PxVec3 localNormal = newSphereCenter - localHit;
const PxReal m = localNormal.normalize();
if(m<1e-3f)
tri.normal(localNormal);
hit = localHit;
normal = localNormal;
}
// PT: not inlining this rarely-run function makes the benchmark ~500.000 cycles faster...
// PT: using this version all the time makes the benchmark ~300.000 cycles slower. So we just use it as a backup.
static bool runBackupProcedure(PxVec3& hit, PxVec3& normal, const PxVec3& localMotion, const PxVec3& boxExtents, const PxTriangle& triInBoxSpace)
{
const Vec3V v0 = V3LoadU(triInBoxSpace.verts[0]);
const Vec3V v1 = V3LoadU(triInBoxSpace.verts[1]);
const Vec3V v2 = V3LoadU(triInBoxSpace.verts[2]);
const TriangleV triangleV(v0, v1, v2);
// PT: the box is in the triangle's space already
//BoxV boxV(V3LoadU(PxVec3(0.0f)), V3LoadU(boxExtents),
// V3LoadU(PxVec3(1.0f, 0.0f, 0.0f)), V3LoadU(PxVec3(0.0f, 1.0f, 0.0f)), V3LoadU(PxVec3(0.0f, 0.0f, 1.0f)));
const BoxV boxV(V3Zero(), V3LoadU(boxExtents));
Vec3V closestA;
Vec3V closestB;
Vec3V normalV;
FloatV distV;
LocalConvex<TriangleV> convexA(triangleV);
LocalConvex<BoxV> convexB(boxV);
const Vec3V initialSearchDir = V3Sub(triangleV.getCenter(), boxV.getCenter());
const FloatV contactDist = FMax();
GjkStatus status_ = gjk<LocalConvex<TriangleV>, LocalConvex<BoxV> >(convexA, convexB, initialSearchDir, contactDist, closestA, closestB, normalV, distV);
if(status_==GJK_CONTACT)
return false;
PxVec3 ml_closestB;
PxVec3 ml_normal;
V3StoreU(closestB, ml_closestB);
V3StoreU(normalV, ml_normal);
hit = ml_closestB + localMotion;
// normal = -ml_normal;
if((ml_normal.dot(localMotion))>0.0f)
ml_normal = -ml_normal;
normal = ml_normal;
return true;
}
void Gu::computeBoxTriImpactData(PxVec3& hit, PxVec3& normal, const PxVec3& boxExtents, const PxVec3& localDir, const PxTriangle& triInBoxSpace, PxReal impactDist)
{
// PT: the triangle is in "box space", i.e. the box can be seen as an AABB centered around the origin.
// PT: compute impact point/normal in a second pass. Here we simply re-sweep the box against the best triangle,
// using the feature-based code (which computes impact point and normal). This is not great because:
// - we know there's an impact so why do all tests again?
// - the SAT test & the feature-based tests could return different results because of FPU accuracy.
// The backup procedure makes sure we compute a proper answer even when the SAT and feature-based versions differ.
const PxBounds3 aabb(-boxExtents, boxExtents);
const PxVec3 oneOverDir(
localDir.x!=0.0f ? 1.0f/localDir.x : 0.0f,
localDir.y!=0.0f ? 1.0f/localDir.y : 0.0f,
localDir.z!=0.0f ? 1.0f/localDir.z : 0.0f);
// PT: TODO: this is the only place left using sweepBoxTriangle()
// Backface culling could be removed here since we know we want a hit no matter what. Plus, it's sometimes
// incorrectly culled and we hit the backup procedure for no reason. On Win32Modern for unknown reasons
// returned normal is sometimes (0,0,0). In these cases we also switch to the backup procedure.
float t = PX_MAX_F32; // PT: no need to initialize with best dist here since we want a hit no matter what
if(!sweepBoxTriangle(triInBoxSpace, aabb, localDir, oneOverDir, hit, normal, t) || normal.isZero())
{
// PT: move triangle close to box
const PxVec3 localMotion = localDir*impactDist;
const PxVec3 delta = localMotion - localDir*GU_SAFE_DISTANCE_FOR_NORMAL_COMPUTATION;
const PxTriangle movedTriangle(
triInBoxSpace.verts[0] - delta,
triInBoxSpace.verts[1] - delta,
triInBoxSpace.verts[2] - delta);
if(!runBackupProcedure(hit, normal, localMotion, boxExtents, movedTriangle))
{
// PT: if the backup procedure fails, we give up
hit = PxVec3(0.0f);
normal = -localDir;
}
}
}
// PT: copy where we know that input vectors are not zero
static PX_FORCE_INLINE void edgeEdgeDistNoZeroVector( PxVec3& x, PxVec3& y, // closest points
const PxVec3& p, const PxVec3& a, // seg 1 origin, vector
const PxVec3& q, const PxVec3& b) // seg 2 origin, vector
{
const PxVec3 T = q - p;
const PxReal ADotA = a.dot(a);
const PxReal BDotB = b.dot(b);
PX_ASSERT(ADotA!=0.0f);
PX_ASSERT(BDotB!=0.0f);
const PxReal ADotB = a.dot(b);
const PxReal ADotT = a.dot(T);
const PxReal BDotT = b.dot(T);
// t parameterizes ray (p, a)
// u parameterizes ray (q, b)
// Compute t for the closest point on ray (p, a) to ray (q, b)
const PxReal Denom = ADotA*BDotB - ADotB*ADotB;
PxReal t;
if(Denom!=0.0f)
{
t = (ADotT*BDotB - BDotT*ADotB) / Denom;
// Clamp result so t is on the segment (p, a)
if(t<0.0f) t = 0.0f;
else if(t>1.0f) t = 1.0f;
}
else
{
t = 0.0f;
}
// find u for point on ray (q, b) closest to point at t
PxReal u;
{
u = (t*ADotB - BDotT) / BDotB;
// if u is on segment (q, b), t and u correspond to closest points, otherwise, clamp u, recompute and clamp t
if(u<0.0f)
{
u = 0.0f;
t = ADotT / ADotA;
if(t<0.0f) t = 0.0f;
else if(t>1.0f) t = 1.0f;
}
else if(u > 1.0f)
{
u = 1.0f;
t = (ADotB + ADotT) / ADotA;
if(t<0.0f) t = 0.0f;
else if(t>1.0f) t = 1.0f;
}
}
x = p + a * t;
y = q + b * u;
}
void Gu::computeEdgeEdgeNormal(PxVec3& normal, const PxVec3& p1, const PxVec3& p2_p1, const PxVec3& p3, const PxVec3& p4_p3, const PxVec3& dir, float d)
{
// PT: cross-product doesn't produce nice normals so we use an edge-edge distance function itself
// PT: move the edges "0.1" units from each other before the computation. If the edges are too far
// away, computed normal tend to align itself with the swept direction. If the edges are too close,
// closest points x and y become identical and we can't compute a proper normal.
const PxVec3 p1s = p1 + dir*(d-GU_SAFE_DISTANCE_FOR_NORMAL_COMPUTATION);
PxVec3 x, y;
edgeEdgeDistNoZeroVector(x, y, p1s, p2_p1, p3, p4_p3);
normal = x - y;
}
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