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Add transform support to deal with Bullets centering of shapes

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This commit is contained in:
Bastiaan Olij 2019-04-25 13:03:48 +10:00
parent 4bb0df7060
commit e4dea0595a
5 changed files with 30 additions and 17 deletions
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2
doc/classes/HeightMapShape.xml
View file

@ -4,7 +4,7 @@
Height map shape for 3D physics (Bullet only).
</brief_description>
<description>
Height map shape resource, which can be added to a [PhysicsBody] or [Area]. Note that bullet will always center the collision shape. If you minimum height is 0, and you maximum height is 10, bullet will adjust your collision shape down so the minimum height is -5 and the maximum height is 5.
Height map shape resource, which can be added to a [PhysicsBody] or [Area].
</description>
<tutorials>
</tutorials>

24
modules/bullet/collision_object_bullet.cpp
View file

@ -59,6 +59,25 @@ void CollisionObjectBullet::ShapeWrapper::set_transform(const btTransform &p_tra
transform = p_transform;
}
btTransform CollisionObjectBullet::ShapeWrapper::get_adjusted_transform() const {
if (shape->get_type() == PhysicsServer::SHAPE_HEIGHTMAP) {
const HeightMapShapeBullet *hm_shape = (const HeightMapShapeBullet *)shape; // should be safe to cast now
btTransform adjusted_transform;
// Bullet centers our heightmap:
// https://github.com/bulletphysics/bullet3/blob/master/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h#L33
// This is really counter intuitive so we're adjusting for it
adjusted_transform.setIdentity();
adjusted_transform.setOrigin(btVector3(0.0, hm_shape->min_height + ((hm_shape->max_height - hm_shape->min_height) * 0.5), 0.0));
adjusted_transform *= transform;
return adjusted_transform;
} else {
return transform;
}
}
void CollisionObjectBullet::ShapeWrapper::claim_bt_shape(const btVector3 &body_scale) {
if (!bt_shape) {
if (active)
@ -345,7 +364,8 @@ void RigidCollisionObjectBullet::reload_shapes() {
// Try to optimize by not using compound
if (1 == shape_count) {
shpWrapper = &shapes.write[0];
if (shpWrapper->transform.getOrigin().isZero() && shpWrapper->transform.getBasis() == shpWrapper->transform.getBasis().getIdentity()) {
btTransform transform = shpWrapper->get_adjusted_transform();
if (transform.getOrigin().isZero() && transform.getBasis() == transform.getBasis().getIdentity()) {
shpWrapper->claim_bt_shape(body_scale);
mainShape = shpWrapper->bt_shape;
main_shape_changed();
@ -359,7 +379,7 @@ void RigidCollisionObjectBullet::reload_shapes() {
for (int i(0); i < shape_count; ++i) {
shpWrapper = &shapes.write[i];
shpWrapper->claim_bt_shape(body_scale);
btTransform scaled_shape_transform(shpWrapper->transform);
btTransform scaled_shape_transform(shpWrapper->get_adjusted_transform());
scaled_shape_transform.getOrigin() *= body_scale;
compoundShape->addChildShape(scaled_shape_transform, shpWrapper->bt_shape);
}

1
modules/bullet/collision_object_bullet.h
View file

@ -109,6 +109,7 @@ public:
void set_transform(const Transform &p_transform);
void set_transform(const btTransform &p_transform);
btTransform get_adjusted_transform() const;
void claim_bt_shape(const btVector3 &body_scale);
};

4
scene/3d/collision_shape.cpp
View file

@ -65,7 +65,6 @@ void CollisionShape::make_convex_from_brothers() {
}
void CollisionShape::_update_in_shape_owner(bool p_xform_only) {
parent->shape_owner_set_transform(owner_id, get_transform());
if (p_xform_only)
return;
@ -228,6 +227,9 @@ void CollisionShape::_update_debug_shape() {
}
void CollisionShape::_shape_changed() {
// If this is a heightfield shape our center may have changed
_update_in_shape_owner(true);
if (is_inside_tree() && get_tree()->is_debugging_collisions_hint() && !debug_shape_dirty) {
debug_shape_dirty = true;
call_deferred("_update_debug_shape");

16
scene/resources/height_map_shape.cpp
View file

@ -44,16 +44,6 @@ Vector<Vector3> HeightMapShape::_gen_debug_mesh_lines() {
PoolRealArray::Read r = map_data.read();
// Bullet centers our heightmap, this is really counter intuitive but for now we'll adjust our debug shape accordingly:
// https://github.com/bulletphysics/bullet3/blob/master/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h#L33
float min = r[0];
float max = r[0];
for (int i = 0; i < map_data.size(); i++) {
if (min > r[i]) min = r[i];
if (max < r[i]) max = r[i];
};
float center = min + ((max - min) * 0.5);
// reserve some memory for our points..
points.resize(((map_width - 1) * map_depth * 2) + (map_width * (map_depth - 1) * 2));
@ -64,16 +54,16 @@ Vector<Vector3> HeightMapShape::_gen_debug_mesh_lines() {
Vector3 height(start.x, 0.0, start.y);
for (int w = 0; w < map_width; w++) {
height.y = r[r_offset++] - center;
height.y = r[r_offset++];
if (w != map_width - 1) {
points.write[w_offset++] = height;
points.write[w_offset++] = Vector3(height.x + 1.0, r[r_offset] - center, height.z);
points.write[w_offset++] = Vector3(height.x + 1.0, r[r_offset], height.z);
}
if (d != map_depth - 1) {
points.write[w_offset++] = height;
points.write[w_offset++] = Vector3(height.x, r[r_offset + map_width - 1] - center, height.z + 1.0);
points.write[w_offset++] = Vector3(height.x, r[r_offset + map_width - 1], height.z + 1.0);
}
height.x += 1.0;