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Cylinder support in Godot Physics 3D

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Cylinder collision detection uses a mix of SAT and GJKEPA.
GJKEPA is used to find the best separation axis in cases where finding
it analytically is too complex.

Changes in SAT solver:
Added support for generating separation axes for cylinder shape.
Added support for generating contact points with circle feature.

Changes in GJKEPA solver:
Updated from latest Bullet version which includes EPA fixes in some
scenarios.
Setting a lower EPA_ACCURACY to fix accuracy problems with cylinder vs.
cylinder in some cases.
This commit is contained in:
PouleyKetchoupp 2021-02-09 11:25:29 -07:00
parent 1808f1d76d
commit 333f184734
8 changed files with 1077 additions and 82 deletions
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33
core/math/geometry_3d.h
View file

@ -252,27 +252,34 @@ public:
return true;
}
static inline bool segment_intersects_cylinder(const Vector3 &p_from, const Vector3 &p_to, real_t p_height, real_t p_radius, Vector3 *r_res = nullptr, Vector3 *r_norm = nullptr) {
static inline bool segment_intersects_cylinder(const Vector3 &p_from, const Vector3 &p_to, real_t p_height, real_t p_radius, Vector3 *r_res = nullptr, Vector3 *r_norm = nullptr, int p_cylinder_axis = 2) {
Vector3 rel = (p_to - p_from);
real_t rel_l = rel.length();
if (rel_l < CMP_EPSILON) {
return false; // Both points are the same.
}
ERR_FAIL_COND_V(p_cylinder_axis < 0, false);
ERR_FAIL_COND_V(p_cylinder_axis > 2, false);
Vector3 cylinder_axis;
cylinder_axis[p_cylinder_axis] = 1.0;
// First check if they are parallel.
Vector3 normal = (rel / rel_l);
Vector3 crs = normal.cross(Vector3(0, 0, 1));
Vector3 crs = normal.cross(cylinder_axis);
real_t crs_l = crs.length();
Vector3 z_dir;
Vector3 axis_dir;
if (crs_l < CMP_EPSILON) {
z_dir = Vector3(1, 0, 0); // Any x/y vector OK.
Vector3 side_axis;
side_axis[(p_cylinder_axis + 1) % 3] = 1.0; // Any side axis OK.
axis_dir = side_axis;
} else {
z_dir = crs / crs_l;
axis_dir = crs / crs_l;
}
real_t dist = z_dir.dot(p_from);
real_t dist = axis_dir.dot(p_from);
if (dist >= p_radius) {
return false; // Too far away.
@ -285,10 +292,10 @@ public:
}
Size2 size(Math::sqrt(w2), p_height * 0.5);
Vector3 x_dir = z_dir.cross(Vector3(0, 0, 1)).normalized();
Vector3 side_dir = axis_dir.cross(cylinder_axis).normalized();
Vector2 from2D(x_dir.dot(p_from), p_from.z);
Vector2 to2D(x_dir.dot(p_to), p_to.z);
Vector2 from2D(side_dir.dot(p_from), p_from[p_cylinder_axis]);
Vector2 to2D(side_dir.dot(p_to), p_to[p_cylinder_axis]);
real_t min = 0, max = 1;
@ -335,10 +342,12 @@ public:
Vector3 res_normal = result;
if (axis == 0) {
res_normal.z = 0;
res_normal[p_cylinder_axis] = 0;
} else {
res_normal.x = 0;
res_normal.y = 0;
int axis_side = (p_cylinder_axis + 1) % 3;
res_normal[axis_side] = 0;
axis_side = (axis_side + 1) % 3;
res_normal[axis_side] = 0;
}
res_normal.normalize();