1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of NVIDIA CORPORATION nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// 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/PxVec3.h"
#include "GuIntersectionRaySphere.h"
#include "GuIntersectionRay.h"
using namespace physx;
// Based on GD Mag code, but now works correctly when origin is inside the sphere.
// This version has limited accuracy.
bool Gu::intersectRaySphereBasic(const PxVec3& origin, const PxVec3& dir, PxReal length, const PxVec3& center, PxReal radius, PxReal& dist, PxVec3* hit_pos)
{
// get the offset vector
const PxVec3 offset = center - origin;
// get the distance along the ray to the center point of the sphere
const PxReal ray_dist = dir.dot(offset);
// get the squared distances
const PxReal off2 = offset.dot(offset);
const PxReal rad_2 = radius * radius;
if(off2 <= rad_2)
{
// we're in the sphere
if(hit_pos)
*hit_pos = origin;
dist = 0.0f;
return true;
}
if(ray_dist <= 0 || (ray_dist - length) > radius)
{
// moving away from object or too far away
return false;
}
// find hit distance squared
const PxReal d = rad_2 - (off2 - ray_dist * ray_dist);
if(d<0.0f)
{
// ray passes by sphere without hitting
return false;
}
// get the distance along the ray
dist = ray_dist - PxSqrt(d);
if(dist > length)
{
// hit point beyond length
return false;
}
// sort out the details
if(hit_pos)
*hit_pos = origin + dir * dist;
return true;
}
// PT: modified version calls the previous function, but moves the ray origin closer to the sphere. The test accuracy is
// greatly improved as a result. This is an idea proposed on the GD-Algorithms list by Eddie Edwards.
// See: http://www.codercorner.com/blog/?p=321
bool Gu::intersectRaySphere(const PxVec3& origin, const PxVec3& dir, PxReal length, const PxVec3& center, PxReal radius, PxReal& dist, PxVec3* hit_pos)
{
const PxVec3 x = origin - center;
PxReal l = PxSqrt(x.dot(x)) - radius - GU_RAY_SURFACE_OFFSET;
// if(l<0.0f)
// l=0.0f;
l = physx::intrinsics::selectMax(l, 0.0f);
bool status = intersectRaySphereBasic(origin + l*dir, dir, length - l, center, radius, dist, hit_pos);
if(status)
{
// dist += l/length;
dist += l;
}
return status;
}
|