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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.
#ifndef PX_PHYSICS_COMMON_CONELIMITHELPER
#define PX_PHYSICS_COMMON_CONELIMITHELPER
// This class contains methods for supporting the tan-quarter swing limit - that
// is the, ellipse defined by tanQ(theta)^2/tanQ(thetaMax)^2 + tanQ(phi)^2/tanQ(phiMax)^2 = 1
//
// Angles are passed as an PxVec3 swing vector with x = 0 and y and z the swing angles
// around the y and z axes
#include "CmPhysXCommon.h"
#include "PsMathUtils.h"
namespace physx
{
namespace Cm
{
PX_FORCE_INLINE PxReal tanAdd(PxReal tan1, PxReal tan2)
{
PX_ASSERT(PxAbs(1-tan1*tan2)>1e-6f);
return (tan1+tan2)/(1-tan1*tan2);
}
// this is here because it's used in both LL and Extensions. However, it
// should STAY IN THE SDK CODE BASE because it's SDK-specific
class ConeLimitHelper
{
public:
ConeLimitHelper(PxReal tanQSwingY, PxReal tanQSwingZ, PxReal tanQPadding)
: mTanQYMax(tanQSwingY), mTanQZMax(tanQSwingZ), mTanQPadding(tanQPadding) {}
// whether the point is inside the (inwardly) padded cone - if it is, there's no limit
// constraint
PX_FORCE_INLINE bool contains(const PxVec3& tanQSwing)
{
PxReal tanQSwingYPadded = tanAdd(PxAbs(tanQSwing.y),mTanQPadding);
PxReal tanQSwingZPadded = tanAdd(PxAbs(tanQSwing.z),mTanQPadding);
return Ps::sqr(tanQSwingYPadded/mTanQYMax)+Ps::sqr(tanQSwingZPadded/mTanQZMax) <= 1;
}
PX_FORCE_INLINE PxVec3 clamp(const PxVec3& tanQSwing,
PxVec3& normal)
{
PxVec3 p = Ps::ellipseClamp(tanQSwing, PxVec3(0,mTanQYMax,mTanQZMax));
normal = PxVec3(0, p.y/Ps::sqr(mTanQYMax), p.z/Ps::sqr(mTanQZMax));
#ifdef PX_PARANOIA_ELLIPSE_CHECK
PxReal err = PxAbs(Ps::sqr(p.y/mTanQYMax) + Ps::sqr(p.z/mTanQZMax) - 1);
PX_ASSERT(err<1e-3);
#endif
return p;
}
// input is a swing quat, such that swing.x = twist.y = twist.z = 0, q = swing * twist
// The routine is agnostic to the sign of q.w (i.e. we don't need the minimal-rotation swing)
// output is an axis such that positive rotation increases the angle outward from the
// limit (i.e. the image of the x axis), the error is the sine of the angular difference,
// positive if the twist axis is inside the cone
bool getLimit(const PxQuat& swing, PxVec3& axis, PxReal& error)
{
PX_ASSERT(swing.w>0);
PxVec3 twistAxis = swing.getBasisVector0();
PxVec3 tanQSwing = PxVec3(0, Ps::tanHalf(swing.z,swing.w), -Ps::tanHalf(swing.y,swing.w));
if(contains(tanQSwing))
return false;
PxVec3 normal, clamped = clamp(tanQSwing, normal);
// rotation vector and ellipse normal
PxVec3 r(0,-clamped.z,clamped.y), d(0, -normal.z, normal.y);
// the point on the cone defined by the tanQ swing vector r
PxVec3 p(1.f,0,0);
PxReal r2 = r.dot(r), a = 1-r2, b = 1/(1+r2), b2 = b*b;
PxReal v1 = 2*a*b2;
PxVec3 v2(a, 2*r.z, -2*r.y); // a*p + 2*r.cross(p);
PxVec3 coneLine = v1 * v2 - p; // already normalized
// the derivative of coneLine in the direction d
PxReal rd = r.dot(d);
PxReal dv1 = -4*rd*(3-r2)*b2*b;
PxVec3 dv2(-2*rd, 2*d.z, -2*d.y);
PxVec3 coneNormal = v1 * dv2 + dv1 * v2;
axis = coneLine.cross(coneNormal)/coneNormal.magnitude();
error = coneLine.cross(axis).dot(twistAxis);
PX_ASSERT(PxAbs(axis.magnitude()-1)<1e-5f);
#ifdef PX_PARANOIA_ELLIPSE_CHECK
bool inside = Ps::sqr(tanQSwing.y/mTanQYMax) + Ps::sqr(tanQSwing.z/mTanQZMax) <= 1;
PX_ASSERT(inside && error>-1e-4f || !inside && error<1e-4f);
#endif
return true;
}
private:
PxReal mTanQYMax, mTanQZMax, mTanQPadding;
};
} // namespace Cm
}
#endif
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