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Fix PathFollow rotations.

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Used parallel transport to move the object along the curve. Also introduced a few more math checks useful for debugging.
This commit is contained in:
Ferenc Arn 2017-05-22 17:06:42 -05:00
parent 9e2b3f0903
commit a1c8896d9d
4 changed files with 57 additions and 36 deletions
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6
core/math/matrix3.h
View file

@ -145,6 +145,12 @@ public:
elements[2][1] = zy;
elements[2][2] = zz;
}
_FORCE_INLINE_ void set(const Vector3 &p_x, const Vector3 &p_y, const Vector3 &p_z) {
set_axis(0, p_x);
set_axis(1, p_y);
set_axis(2, p_z);
}
_FORCE_INLINE_ Vector3 get_column(int i) const {
return Vector3(elements[0][i], elements[1][i], elements[2][i]);

13
core/math/transform.cpp
View file

@ -82,7 +82,10 @@ Transform Transform::looking_at(const Vector3 &p_target, const Vector3 &p_up) co
}
void Transform::set_look_at(const Vector3 &p_eye, const Vector3 &p_target, const Vector3 &p_up) {
#ifdef MATH_CHECKS
ERR_FAIL_COND(p_eye == p_target);
ERR_FAIL_COND(p_up.length() == 0);
#endif
// Reference: MESA source code
Vector3 v_x, v_y, v_z;
@ -96,6 +99,9 @@ void Transform::set_look_at(const Vector3 &p_eye, const Vector3 &p_target, const
v_y = p_up;
v_x = v_y.cross(v_z);
#ifdef MATH_CHECKS
ERR_FAIL_COND(v_x.length() == 0);
#endif
/* Recompute Y = Z cross X */
v_y = v_z.cross(v_x);
@ -103,9 +109,8 @@ void Transform::set_look_at(const Vector3 &p_eye, const Vector3 &p_target, const
v_x.normalize();
v_y.normalize();
basis.set_axis(0, v_x);
basis.set_axis(1, v_y);
basis.set_axis(2, v_z);
basis.set(v_x, v_y, v_z);
origin = p_eye;
}

10
core/math/transform.h
View file

@ -97,15 +97,7 @@ public:
void set(real_t xx, real_t xy, real_t xz, real_t yx, real_t yy, real_t yz, real_t zx, real_t zy, real_t zz, real_t tx, real_t ty, real_t tz) {
basis.elements[0][0] = xx;
basis.elements[0][1] = xy;
basis.elements[0][2] = xz;
basis.elements[1][0] = yx;
basis.elements[1][1] = yy;
basis.elements[1][2] = yz;
basis.elements[2][0] = zx;
basis.elements[2][1] = zy;
basis.elements[2][2] = zz;
basis.set(xx, xy, xz, yx, yy, yz, zx, zy, zz);
origin.x = tx;
origin.y = ty;
origin.z = tz;

64
scene/3d/path.cpp
View file

@ -108,40 +108,58 @@ void PathFollow::_update_transform() {
Vector3 pos = c->interpolate_baked(o, cubic);
Transform t = get_transform();
t.origin = pos;
Vector3 pos_offset = Vector3(h_offset, v_offset, 0);
if (rotation_mode != ROTATION_NONE) {
// perform parallel transport
//
// see C. Dougan, The Parallel Transport Frame, Game Programming Gems 2 for example
// for a discussion about why not Frenet frame.
Vector3 n = (c->interpolate_baked(o + lookahead, cubic) - pos).normalized();
Vector3 t_prev = pos - c->interpolate_baked(o - lookahead, cubic);
Vector3 t_cur = c->interpolate_baked(o + lookahead, cubic) - pos;
if (rotation_mode == ROTATION_Y) {
Vector3 axis = t_prev.cross(t_cur);
float dot = t_prev.normalized().dot(t_cur.normalized());
float angle = Math::acos(CLAMP(dot, -1, 1));
n.y = 0;
n.normalize();
}
if (n.length() < CMP_EPSILON) { //nothing, use previous
n = -t.get_basis().get_axis(2).normalized();
}
Vector3 up = Vector3(0, 1, 0);
if (rotation_mode == ROTATION_XYZ) {
float tilt = c->interpolate_baked_tilt(o);
if (tilt != 0) {
Basis rot(-n, tilt); //remember.. lookat will be znegative.. znegative!! we abide by opengl clan.
up = rot.xform(up);
if (axis.length() > CMP_EPSILON && angle > CMP_EPSILON) {
if (rotation_mode == ROTATION_Y) {
// assuming we're referring to global Y-axis. is this correct?
axis.x = 0;
axis.z = 0;
} else if (rotation_mode == ROTATION_XY) {
axis.z = 0;
} else if (rotation_mode == ROTATION_XYZ) {
// all components are OK
}
t.rotate_basis(axis.normalized(), angle);
}
t.set_look_at(pos, pos + n, up);
// do the additional tilting
float tilt_angle = c->interpolate_baked_tilt(o);
Vector3 tilt_axis = t_cur; // is this correct??
if (tilt_axis.length() > CMP_EPSILON && tilt_angle > CMP_EPSILON) {
if (rotation_mode == ROTATION_Y) {
tilt_axis.x = 0;
tilt_axis.z = 0;
} else if (rotation_mode == ROTATION_XY) {
tilt_axis.z = 0;
} else if (rotation_mode == ROTATION_XYZ) {
// all components are OK
}
t.rotate_basis(tilt_axis.normalized(), tilt_angle);
}
t.translate(pos_offset);
} else {
t.origin = pos;
t.origin += pos_offset;
}
t.origin += t.basis.get_axis(0) * h_offset + t.basis.get_axis(1) * v_offset;
set_transform(t);
}