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Write once ray cast on triangle function

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This commit is contained in:
Irlan 2019-05-13 16:23:05 -03:00
parent 3e5ff2257a
commit 31cac5aacd
4 changed files with 105 additions and 144 deletions
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4
include/bounce/collision/collision.h
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@ -37,4 +37,8 @@ struct b3RayCastOutput
b3Vec3 normal; // surface normal of intersection
};
// Perform a ray-cast on a triangle.
bool b3RayCast(b3RayCastOutput* output, const b3RayCastInput* input,
const b3Vec3& v1, const b3Vec3& v2, const b3Vec3& v3);
#endif

84
src/bounce/cloth/cloth.cpp
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@ -396,92 +396,19 @@ bool b3Cloth::RayCast(b3RayCastOutput* output, const b3RayCastInput* input, u32
b3Vec3 v2 = m_vertexParticles[triangle->v2]->m_position;
b3Vec3 v3 = m_vertexParticles[triangle->v3]->m_position;
b3Vec3 p1 = input->p1;
b3Vec3 p2 = input->p2;
float32 maxFraction = input->maxFraction;
b3Vec3 d = p2 - p1;
B3_ASSERT(b3LengthSquared(d) > B3_EPSILON * B3_EPSILON);
b3Vec3 n = b3Cross(v2 - v1, v3 - v1);
float32 len = b3Length(n);
if (len <= B3_EPSILON)
{
return false;
}
n /= len;
float32 numerator = b3Dot(n, v1 - p1);
float32 denominator = b3Dot(n, d);
if (denominator == 0.0f)
{
return false;
}
float32 fraction = numerator / denominator;
// Is the intersection not on the segment?
if (fraction < 0.0f || maxFraction < fraction)
{
return false;
}
b3Vec3 Q = p1 + fraction * d;
b3Vec3 A = v1;
b3Vec3 B = v2;
b3Vec3 C = v3;
b3Vec3 AB = B - A;
b3Vec3 AC = C - A;
b3Vec3 QA = A - Q;
b3Vec3 QB = B - Q;
b3Vec3 QC = C - Q;
b3Vec3 QB_x_QC = b3Cross(QB, QC);
b3Vec3 QC_x_QA = b3Cross(QC, QA);
b3Vec3 QA_x_QB = b3Cross(QA, QB);
b3Vec3 AB_x_AC = b3Cross(AB, AC);
// Barycentric coordinates for Q
float32 u = b3Dot(QB_x_QC, AB_x_AC);
float32 v = b3Dot(QC_x_QA, AB_x_AC);
float32 w = b3Dot(QA_x_QB, AB_x_AC);
// Is the intersection on the triangle?
if (u >= 0.0f && v >= 0.0f && w >= 0.0f)
{
output->fraction = fraction;
// Does the ray start from below or above the triangle?
if (numerator > 0.0f)
{
output->normal = -n;
}
else
{
output->normal = n;
}
return true;
}
return false;
return b3RayCast(output, input, v1, v2, v3);
}
void b3Cloth::UpdateBodyContacts()
{
B3_PROFILE("Cloth Update Body Contacts");
// Is there a world attached to this cloth?
if (m_world == nullptr)
{
return;
}
B3_PROFILE("Cloth Update Body Contacts");
// Create contacts
for (b3Particle* p = m_particleList.m_head; p; p = p->m_next)
{
@ -690,11 +617,6 @@ void b3Cloth::UpdateContacts()
{
// Update body contacts
UpdateBodyContacts();
#if 0
// Update particle contacts
UpdateParticleContacts();
#endif
}
void b3Cloth::Step(float32 dt)

90
src/bounce/collision/collision.cpp
View File

@ -16,6 +16,8 @@
* 3. This notice may not be removed or altered from any source distribution.
*/
#include <bounce/collision/collision.h>
#include <bounce/collision/shapes/sphere.h>
#include <bounce/collision/shapes/capsule.h>
#include <bounce/collision/shapes/box_hull.h>
@ -24,4 +26,90 @@ const b3Sphere b3Sphere_identity(b3Vec3_zero, 1.0f);
const b3Capsule b3Capsule_identity(b3Vec3(0.0f, -0.5f, 0.0f), b3Vec3(0.0f, 0.5f, 0.0f), 1.0f);
const b3BoxHull b3BoxHull_identity(1.0f, 1.0f, 1.0f);
const b3BoxHull b3BoxHull_identity(1.0f, 1.0f, 1.0f);
bool b3RayCast(b3RayCastOutput* output,
const b3RayCastInput* input,
const b3Vec3& v1, const b3Vec3& v2, const b3Vec3& v3)
{
b3Vec3 p1 = input->p1;
b3Vec3 p2 = input->p2;
float32 maxFraction = input->maxFraction;
b3Vec3 d = p2 - p1;
if (b3LengthSquared(d) < B3_EPSILON * B3_EPSILON)
{
return false;
}
b3Vec3 n = b3Cross(v2 - v1, v3 - v1);
float32 len = b3Length(n);
if (len == 0.0f)
{
return false;
}
n /= len;
float32 num = b3Dot(n, v1 - p1);
float32 den = b3Dot(n, d);
if (den == 0.0f)
{
return false;
}
float32 fraction = num / den;
// Is the intersection not on the segment?
if (fraction < 0.0f || maxFraction < fraction)
{
return false;
}
b3Vec3 Q = p1 + fraction * d;
b3Vec3 A = v1;
b3Vec3 B = v2;
b3Vec3 C = v3;
b3Vec3 AB = B - A;
b3Vec3 AC = C - A;
b3Vec3 QA = A - Q;
b3Vec3 QB = B - Q;
b3Vec3 QC = C - Q;
b3Vec3 QB_x_QC = b3Cross(QB, QC);
b3Vec3 QC_x_QA = b3Cross(QC, QA);
b3Vec3 QA_x_QB = b3Cross(QA, QB);
b3Vec3 AB_x_AC = b3Cross(AB, AC);
// Barycentric coordinates for Q
float32 u = b3Dot(QB_x_QC, AB_x_AC);
float32 v = b3Dot(QC_x_QA, AB_x_AC);
float32 w = b3Dot(QA_x_QB, AB_x_AC);
// Is the intersection on the triangle?
if (u >= 0.0f && v >= 0.0f && w >= 0.0f)
{
output->fraction = fraction;
// Does the ray start from below or above the triangle?
if (num > 0.0f)
{
output->normal = -n;
}
else
{
output->normal = n;
}
return true;
}
return false;
}

71
src/bounce/dynamics/shapes/mesh_shape.cpp
View File

@ -112,6 +112,7 @@ bool b3MeshShape::RayCast(b3RayCastOutput* output, const b3RayCastInput& input,
{
B3_ASSERT(index < m_mesh->triangleCount);
b3Triangle* triangle = m_mesh->triangles + index;
b3Vec3 v1 = m_mesh->vertices[triangle->v1];
b3Vec3 v2 = m_mesh->vertices[triangle->v2];
b3Vec3 v3 = m_mesh->vertices[triangle->v3];
@ -119,71 +120,17 @@ bool b3MeshShape::RayCast(b3RayCastOutput* output, const b3RayCastInput& input,
// Put the ray into the mesh's frame of reference.
b3Vec3 p1 = b3MulT(xf, input.p1);
b3Vec3 p2 = b3MulT(xf, input.p2);
b3Vec3 d = p2 - p1;
b3Vec3 n = b3Cross(v2 - v1, v3 - v1);
n.Normalize();
float32 numerator = b3Dot(n, v1 - p1);
float32 denominator = b3Dot(n, d);
b3RayCastInput subInput;
subInput.p1 = p1;
subInput.p2 = p2;
subInput.maxFraction = input.maxFraction;
if (denominator == 0.0f)
b3RayCastOutput subOutput;
if (b3RayCast(&subOutput, &subInput, v1, v2, v3))
{
return false;
}
float32 t = numerator / denominator;
// Is the intersection not on the segment?
if (t < 0.0f || input.maxFraction < t)
{
return false;
}
b3Vec3 q = p1 + t * d;
// Barycentric coordinates for q
b3Vec3 Q = q;
b3Vec3 A = v1;
b3Vec3 B = v2;
b3Vec3 C = v3;
b3Vec3 AB = B - A;
b3Vec3 AC = C - A;
b3Vec3 QA = A - Q;
b3Vec3 QB = B - Q;
b3Vec3 QC = C - Q;
b3Vec3 QB_x_QC = b3Cross(QB, QC);
b3Vec3 QC_x_QA = b3Cross(QC, QA);
b3Vec3 QA_x_QB = b3Cross(QA, QB);
b3Vec3 AB_x_AC = b3Cross(AB, AC);
float32 u = b3Dot(QB_x_QC, AB_x_AC);
float32 v = b3Dot(QC_x_QA, AB_x_AC);
float32 w = b3Dot(QA_x_QB, AB_x_AC);
// This tolerance helps intersections lying on
// shared edges to not be missed.
const float32 kTol = -0.005f;
// Is the intersection on the triangle?
if (u > kTol && v > kTol && w > kTol)
{
output->fraction = t;
// Does the ray start from below or above the triangle?
if (numerator > 0.0f)
{
output->normal = -b3Mul(xf.rotation, n);
}
else
{
output->normal = b3Mul(xf.rotation, n);
}
output->fraction = subOutput.fraction;
output->normal = xf.rotation * subOutput.normal;
return true;
}