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Fix RayShape collision when used with a KinematicBody (Bullet Physics)

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- Added code handling non-compound collision to recover_from_penetration_ray()
  which is now needed due to the optimization avoiding the use of compound
  collisions when only a single collision shape is used.
- Removed arbitrary margin applied in the collision algorithm of RayShapes
  which causes jittered movement. For lack of a better replacement and for
  lack of any explanation on why it has been introduced, it's now using the
  shape's margin property instead which is small enough to not show visible
  jitter.
- Tried to get rid of inconsistent uses of the collision margin.
- Removed hack from GodotDeepPenetrationContactResultCallback::addContactPoint
  for RayShape collision as it's no longer needed as the collision algorithm
  of RayShapes correctly calculates the contact normal for a while now.

Fixes #25227.
This commit is contained in:
Daniel Rakos 2019-02-11 01:48:33 +01:00
parent 4fd579b271
commit f7511511b1
5 changed files with 32 additions and 29 deletions
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6
modules/bullet/btRayShape.cpp
View file

@ -79,7 +79,7 @@ void btRayShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVecto
void btRayShape::getAabb(const btTransform &t, btVector3 &aabbMin, btVector3 &aabbMax) const {
#define MARGIN_BROADPHASE 0.1
btVector3 localAabbMin(0, 0, 0);
btVector3 localAabbMax(m_shapeAxis * m_length);
btVector3 localAabbMax(m_shapeAxis * (m_cacheScaledLength + m_collisionMargin));
btTransformAabb(localAabbMin, localAabbMax, MARGIN_BROADPHASE, t, aabbMin, aabbMax);
}
@ -97,8 +97,8 @@ void btRayShape::getPreferredPenetrationDirection(int index, btVector3 &penetrat
void btRayShape::reload_cache() {
m_cacheScaledLength = m_length * m_localScaling[2] + m_collisionMargin;
m_cacheScaledLength = m_length * m_localScaling[2];
m_cacheSupportPoint.setIdentity();
m_cacheSupportPoint.setOrigin(m_shapeAxis * m_cacheScaledLength);
m_cacheSupportPoint.setOrigin(m_shapeAxis * (m_cacheScaledLength + m_collisionMargin));
}

6
modules/bullet/godot_ray_world_algorithm.cpp
View file

@ -35,8 +35,6 @@
#include <BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h>
#define RAY_STABILITY_MARGIN 0.1
/**
@author AndreaCatania
*/
@ -102,8 +100,8 @@ void GodotRayWorldAlgorithm::processCollision(const btCollisionObjectWrapper *bo
btScalar depth(ray_shape->getScaledLength() * (btResult.m_closestHitFraction - 1));
if (depth >= -RAY_STABILITY_MARGIN)
depth = 0;
if (depth >= -ray_shape->getMargin())
depth *= 0.5;
if (ray_shape->getSlipsOnSlope())
resultOut->addContactPoint(btResult.m_hitNormalWorld, btResult.m_hitPointWorld, depth);

10
modules/bullet/godot_result_callbacks.cpp
View file

@ -333,14 +333,6 @@ void GodotDeepPenetrationContactResultCallback::addContactPoint(const btVector3
m_other_compound_shape_index = isSwapped ? m_index0 : m_index1;
m_pointWorld = isSwapped ? (pointInWorldOnB + (normalOnBInWorld * depth)) : pointInWorldOnB;
const btCollisionObjectWrapper *bw0 = m_body0Wrap;
if (isSwapped)
bw0 = m_body1Wrap;
if (bw0->getCollisionShape()->getShapeType() == CUSTOM_CONVEX_SHAPE_TYPE) {
m_pointNormalWorld = bw0->m_worldTransform.getBasis().transpose() * btVector3(0, 0, 1);
} else {
m_pointNormalWorld = isSwapped ? normalOnBInWorld * -1 : normalOnBInWorld;
}
m_pointNormalWorld = isSwapped ? normalOnBInWorld * -1 : normalOnBInWorld;
}
}

38
modules/bullet/space_bullet.cpp
View file

@ -1224,6 +1224,21 @@ bool SpaceBullet::RFP_convex_world_test(const btConvexShape *p_shapeA, const btC
return false;
}
void SpaceBullet::convert_to_separation_result(PhysicsServer::SeparationResult *r_result, const SpaceBullet::RecoverResult &p_recover_result, int p_shape_id, const btCollisionObject *p_other_object) const {
const btRigidBody *btRigid = static_cast<const btRigidBody *>(p_other_object);
CollisionObjectBullet *collisionObject = static_cast<CollisionObjectBullet *>(p_other_object->getUserPointer());
r_result->collision_depth = p_recover_result.penetration_distance;
B_TO_G(p_recover_result.pointWorld, r_result->collision_point);
B_TO_G(p_recover_result.normal, r_result->collision_normal);
B_TO_G(btRigid->getVelocityInLocalPoint(p_recover_result.pointWorld - btRigid->getWorldTransform().getOrigin()), r_result->collider_velocity);
r_result->collision_local_shape = p_shape_id;
r_result->collider_id = collisionObject->get_instance_id();
r_result->collider = collisionObject->get_self();
r_result->collider_shape = p_recover_result.other_compound_shape_index;
}
int SpaceBullet::recover_from_penetration_ray(RigidBodyBullet *p_body, const btTransform &p_body_position, btScalar p_recover_movement_scale, bool p_infinite_inertia, int p_result_max, btVector3 &r_delta_recover_movement, PhysicsServer::SeparationResult *r_results) {
RecoverPenetrationBroadPhaseCallback recover_broad_result(p_body->get_bt_collision_object(), p_body->get_collision_layer(), p_body->get_collision_mask());
@ -1275,22 +1290,19 @@ int SpaceBullet::recover_from_penetration_ray(RigidBodyBullet *p_body, const btT
btCompoundShape *cs = static_cast<btCompoundShape *>(otherObject->getCollisionShape());
for (int x = cs->getNumChildShapes() - 1; 0 <= x; --x) {
RecoverResult r_recover_result;
if (RFP_convex_world_test(kin_shape.shape, cs->getChildShape(x), p_body->get_bt_collision_object(), otherObject, kinIndex, x, body_shape_position, otherObject->getWorldTransform() * cs->getChildTransform(x), p_recover_movement_scale, r_delta_recover_movement, &r_recover_result)) {
RecoverResult recover_result;
if (RFP_convex_world_test(kin_shape.shape, cs->getChildShape(x), p_body->get_bt_collision_object(), otherObject, kinIndex, x, body_shape_position, otherObject->getWorldTransform() * cs->getChildTransform(x), p_recover_movement_scale, r_delta_recover_movement, &recover_result)) {
const btRigidBody *btRigid = static_cast<const btRigidBody *>(otherObject);
CollisionObjectBullet *collisionObject = static_cast<CollisionObjectBullet *>(otherObject->getUserPointer());
r_results[ray_index].collision_depth = r_recover_result.penetration_distance;
B_TO_G(r_recover_result.pointWorld, r_results[ray_index].collision_point);
B_TO_G(r_recover_result.normal, r_results[ray_index].collision_normal);
B_TO_G(btRigid->getVelocityInLocalPoint(r_recover_result.pointWorld - btRigid->getWorldTransform().getOrigin()), r_results[ray_index].collider_velocity);
r_results[ray_index].collision_local_shape = kinIndex;
r_results[ray_index].collider_id = collisionObject->get_instance_id();
r_results[ray_index].collider = collisionObject->get_self();
r_results[ray_index].collider_shape = r_recover_result.other_compound_shape_index;
convert_to_separation_result(&r_results[ray_index], recover_result, kinIndex, otherObject);
}
}
} else {
RecoverResult recover_result;
if (RFP_convex_world_test(kin_shape.shape, otherObject->getCollisionShape(), p_body->get_bt_collision_object(), otherObject, kinIndex, 0, body_shape_position, otherObject->getWorldTransform(), p_recover_movement_scale, r_delta_recover_movement, &recover_result)) {
convert_to_separation_result(&r_results[ray_index], recover_result, kinIndex, otherObject);
}
}
}

1
modules/bullet/space_bullet.h
View file

@ -212,6 +212,7 @@ private:
/// Using this we leave Bullet to select the best algorithm, For example GJK in case we have Convex Convex, or a Bullet accelerated algorithm
bool RFP_convex_world_test(const btConvexShape *p_shapeA, const btCollisionShape *p_shapeB, btCollisionObject *p_objectA, btCollisionObject *p_objectB, int p_shapeId_A, int p_shapeId_B, const btTransform &p_transformA, const btTransform &p_transformB, btScalar p_recover_movement_scale, btVector3 &r_delta_recover_movement, RecoverResult *r_recover_result = NULL);
void convert_to_separation_result(PhysicsServer::SeparationResult *r_result, const SpaceBullet::RecoverResult &p_recover_result, int p_shape_id, const btCollisionObject *p_other_object) const;
int recover_from_penetration_ray(RigidBodyBullet *p_body, const btTransform &p_body_position, btScalar p_recover_movement_scale, bool p_infinite_inertia, int p_result_max, btVector3 &r_delta_recover_movement, PhysicsServer::SeparationResult *r_results);
};
#endif