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call RBs' _physics_rollback_tick(...) with tick rather than NetworkTi… #633

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call RBs' _physics_rollback_tick(...) with tick rather than NetworkTi… #633

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ab67dd5
call RBs' _physics_rollback_tick(...) with tick rather than NetworkTi…
jburdecki Jul 15, 2026
9f8f88a
Change live RID tracking from a loop to a dictionary to decrease look…
jburdecki Jul 16, 2026
835dc7c
Update param naming to match usage
jburdecki Jul 16, 2026
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17 changes: 15 additions & 2 deletions addons/netfox.extras/physics/godot_driver_2d.gd.off
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,11 @@ class_name PhysicsDriver2D
# Requires a custom build of Godot with https://github.com/godotengine/godot/pull/76462

var scene_collision_objects: Array = []

# RIDs of tracked bodies currently in the tree. Snapshot entries whose
# body has been freed are skipped for state updates in rollback
var live_rids: Dictionary = {}

var collision_objects_snapshots: Dictionary[int, Dictionary] = {}

func _init_physics_space() -> void:
Expand Down Expand Up @@ -33,8 +38,10 @@ func _snapshot_space(tick: int) -> void:
func _rollback_space(tick) -> void:
if snapshots.has(tick):
var rid_states = snapshots[tick]
for rid in rid_states.keys():
set_body_states(rid, rid_states[rid])
for rid in rid_states.keys():
# Skip bodies freed or removed since the snapshot was taken
if live_rids.has(rid):
set_body_states(rid, rid_states[rid])

@albertok albertok Jul 15, 2026 •
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Instead of the looping checks maybe we can clear out the object as soon as it's going to queue free.

Instead of node_removed being called from get_tree().node_removed.connect(node_removed) signal on line 16 we directly hook into the https://docs.godotengine.org/en/stable/classes/class_node.html#class-node-signal-tree-exiting signal from the node itself.

We do this in node_added ( second last function in this class ) as the node is being registered.

@jburdecki jburdecki Jul 16, 2026

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I like the idea of moving away from the loop. I changed it to a dictionary to improve lookup times.

Unfortunately though, to your point, tree_exiting() is called on any tree removal (including remove_child(), which could be a valid gameplay operation for moving RBs around a scene's tree/heirarchy). https://docs.godotengine.org/en/stable/classes/class_node.html#class-node-private-method-exit-tree And alternatively checking is_queued_for_deletion() would miss direct free() calls on RBs. So from what I see we're stuck without a proper (engine/solver-driven) event-based approach on this.

@albertok albertok Jul 18, 2026

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Interesting. Are those really valid scenarios?

Calling free will definitely break netfox as will re-parenting.

@elementbound I think you've dealt with these life cycles a lot, what are your thoughts?


for body in scene_collision_objects:
if body is CharacterBody2D or body is AnimatableBody2D:
Expand All @@ -58,6 +65,10 @@ func scan_tree():
scene_collision_objects.clear()
scene_collision_objects = get_all_children(get_node('/root'))

live_rids.clear()
for body in scene_collision_objects:
live_rids[body.get_rid()] = true

func get_all_children(in_node: Node) -> Array:
var nodes = []
nodes = in_node.find_children("*", "PhysicsBody2D", true, false)
Expand All @@ -66,7 +77,9 @@ func get_all_children(in_node: Node) -> Array:
func node_added(node: Node) -> void:
if node is PhysicsBody2D:
scene_collision_objects.append(node)
live_rids[node.get_rid()] = true

func node_removed(node: Node) -> void:
if node is PhysicsBody2D:
scene_collision_objects.erase(node)
live_rids.erase(node.get_rid())
19 changes: 15 additions & 4 deletions addons/netfox.extras/physics/godot_driver_3d.gd.off
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,10 @@ class_name PhysicsDriver3D
# Maps ticks ( int ) to global snapshots ( Dictionary<RID, Array> )
var scene_collision_objects: Array = []

# RIDs of tracked bodies currently in the tree. Snapshot entries whose
# body has been freed are skipped for state updates in rollback
var live_rids: Dictionary = {}

func _init_physics_space() -> void:
physics_space = get_viewport().world_3d.space
PhysicsServer3D.space_set_active(physics_space, false)
Expand All @@ -29,10 +33,12 @@ func _snapshot_space(tick: int) -> void:
snapshots[tick] = rid_states

func _rollback_space(tick) -> void:
if snapshots.has(tick):
var rid_states = snapshots[tick]
for rid in rid_states.keys():
set_body_states(rid, rid_states[rid])
if snapshots.has(tick):
var rid_states = snapshots[tick]
for rid in rid_states.keys():
# Skip bodies freed or removed since the snapshot was taken
if live_rids.has(rid):
set_body_states(rid, rid_states[rid])

for body in scene_collision_objects:
if body is CharacterBody3D or body is AnimatableBody3D:
Expand All @@ -56,6 +62,9 @@ func set_body_states(rid: RID, body_state: Array) -> void:
func scan_tree():
scene_collision_objects.clear()
scene_collision_objects = get_all_children(get_node('/root'))
live_rids.clear()
for body in scene_collision_objects:
live_rids[body.get_rid()] = true

func get_all_children(in_node: Node) -> Array:
var nodes = []
Expand All @@ -65,7 +74,9 @@ func get_all_children(in_node: Node) -> Array:
func node_added(node: Node) -> void:
if node is PhysicsBody3D:
scene_collision_objects.append(node)
live_rids[node.get_rid()] = true

func node_removed(node: Node) -> void:
if node is PhysicsBody3D:
scene_collision_objects.erase(node)
live_rids.erase(node.get_rid())
13 changes: 7 additions & 6 deletions addons/netfox.extras/physics/physics_driver.gd
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Original file line number Diff line number Diff line change
Expand Up @@ -36,9 +36,9 @@ func _ready() -> void:
_init_physics_space()

# Emitted before a tick is run.
func before_tick(_delta: float, tick: int) -> void:
func before_tick(delta: float, tick: int) -> void:
_snapshot_space(tick)
step_physics(_delta)
step_physics(delta, tick)

func on_prepare_tick(tick: int) -> void:
if NetworkRollback._rollback_from == tick:
Expand All @@ -48,22 +48,23 @@ func on_prepare_tick(tick: int) -> void:
# Subsequent ticks are re-writing history.
_snapshot_space(tick)

func on_process_tick(_tick: int) -> void:
step_physics(NetworkTime.ticktime)
func on_process_tick(tick: int) -> void:
step_physics(NetworkTime.ticktime, tick)

func after_tick_loop() -> void:
# Remove old snapshots
for i in snapshots.keys():
if i < NetworkRollback.history_start:
snapshots.erase(i)

func step_physics(_delta: float) -> void:
# tick is either the current tick, or the tick being resimulated (if rollback is active)
func step_physics(delta: float, tick: int) -> void:
# Break up physics into smaller steps if needed
var frac_delta = _delta / physics_factor
var rollback_participants = get_tree().get_nodes_in_group("network_rigid_body")
for i in range(physics_factor):
for net_rigid_body in rollback_participants:
net_rigid_body._physics_rollback_tick(frac_delta, NetworkTime.tick)
net_rigid_body._physics_rollback_tick(frac_delta, tick)

_physics_step(frac_delta)

Expand Down