diff --git a/doc/classes/CPUParticles2D.xml b/doc/classes/CPUParticles2D.xml
index 8111fa4d3cd..0a0fbbd2fac 100644
--- a/doc/classes/CPUParticles2D.xml
+++ b/doc/classes/CPUParticles2D.xml
@@ -236,6 +236,7 @@
Orbital velocity randomness ratio.
+
Particle system starts as if it had already run for this many seconds.
diff --git a/scene/2d/camera_2d.cpp b/scene/2d/camera_2d.cpp
index 51853418ee9..13a79e7847a 100644
--- a/scene/2d/camera_2d.cpp
+++ b/scene/2d/camera_2d.cpp
@@ -301,7 +301,9 @@ void Camera2D::_notification(int p_what) {
}
if (is_physics_interpolated_and_enabled()) {
_ensure_update_interpolation_data();
- _interpolation_data.xform_curr = get_camera_transform();
+ if (Engine::get_singleton()->is_in_physics_frame()) {
+ _interpolation_data.xform_curr = get_camera_transform();
+ }
}
} break;
diff --git a/scene/2d/canvas_item.cpp b/scene/2d/canvas_item.cpp
index 70022a36601..a78a5354b6c 100644
--- a/scene/2d/canvas_item.cpp
+++ b/scene/2d/canvas_item.cpp
@@ -490,6 +490,20 @@ Transform2D CanvasItem::get_global_transform() const {
return global_transform;
}
+// Same as get_global_transform() but no reset for `global_invalid`.
+Transform2D CanvasItem::get_global_transform_const() const {
+ if (global_invalid) {
+ const CanvasItem *pi = get_parent_item();
+ if (pi) {
+ global_transform = pi->get_global_transform_const() * get_transform();
+ } else {
+ global_transform = get_transform();
+ }
+ }
+
+ return global_transform;
+}
+
void CanvasItem::_toplevel_raise_self() {
if (!is_inside_tree()) {
return;
diff --git a/scene/2d/canvas_item.h b/scene/2d/canvas_item.h
index 4f17d733b94..4ee5aef59b2 100644
--- a/scene/2d/canvas_item.h
+++ b/scene/2d/canvas_item.h
@@ -238,6 +238,7 @@ protected:
void item_rect_changed(bool p_size_changed = true);
void set_canvas_item_use_identity_transform(bool p_enable);
+ Transform2D get_global_transform_const() const;
void _notification(int p_what);
static void _bind_methods();
diff --git a/scene/2d/cpu_particles_2d.cpp b/scene/2d/cpu_particles_2d.cpp
index 7c3848fcdb0..7dbb6b9380a 100644
--- a/scene/2d/cpu_particles_2d.cpp
+++ b/scene/2d/cpu_particles_2d.cpp
@@ -30,6 +30,8 @@
#include "cpu_particles_2d.h"
#include "core/core_string_names.h"
+#include "core/fixed_array.h"
+#include "core/math/transform_interpolator.h"
#include "core/os/os.h"
#include "scene/2d/canvas_item.h"
#include "scene/2d/particles_2d.h"
@@ -119,6 +121,10 @@ void CPUParticles2D::set_use_local_coordinates(bool p_enable) {
// When not using legacy, there is never a need for NOTIFICATION_TRANSFORM_CHANGED,
// so we leave it at the default (false).
set_canvas_item_use_identity_transform(!local_coords);
+
+ // We only need NOTIFICATION_TRANSFORM_CHANGED
+ // when following an interpolated target.
+ set_notify_transform(_interpolation_data.interpolated_follow);
#endif
}
@@ -755,7 +761,11 @@ void CPUParticles2D::_particles_process(float p_delta) {
Transform2D emission_xform;
Transform2D velocity_xform;
if (!local_coords) {
- emission_xform = get_global_transform();
+ if (!_interpolation_data.interpolated_follow) {
+ emission_xform = get_global_transform();
+ } else {
+ TransformInterpolator::interpolate_transform_2d(_interpolation_data.global_xform_prev, _interpolation_data.global_xform_curr, emission_xform, Engine::get_singleton()->get_physics_interpolation_fraction());
+ }
velocity_xform = emission_xform;
velocity_xform[2] = Vector2();
}
@@ -1082,7 +1092,14 @@ void CPUParticles2D::_refresh_interpolation_state() {
}
bool interpolated = is_physics_interpolated_and_enabled();
- if (_interpolated == interpolated) {
+ // The logic for whether to do an interpolated follow.
+ // This is rather complex, but basically:
+ // If project setting interpolation is ON but this particle system is switched OFF,
+ // and in global mode, we will follow the INTERPOLATED position rather than the actual position.
+ // This is so that particles aren't generated AHEAD of the interpolated parent.
+ bool follow = !interpolated && !local_coords && get_tree()->is_physics_interpolation_enabled();
+
+ if ((_interpolated == interpolated) && (follow == _interpolation_data.interpolated_follow)) {
return;
}
@@ -1093,14 +1110,13 @@ void CPUParticles2D::_refresh_interpolation_state() {
_set_redraw(false);
_interpolated = interpolated;
+ _interpolation_data.interpolated_follow = follow;
-#ifdef GODOT_CPU_PARTICLES_2D_LEGACY_COMPATIBILITY
// Refresh local coords state, blank inv_emission_transform.
set_use_local_coordinates(local_coords);
-#endif
set_process_internal(!_interpolated);
- set_physics_process_internal(_interpolated);
+ set_physics_process_internal(_interpolated || _interpolation_data.interpolated_follow);
// Re-establish all connections.
_set_redraw(curr_redraw);
@@ -1161,6 +1177,13 @@ void CPUParticles2D::_notification(int p_what) {
if (_interpolated) {
_update_internal(true);
}
+
+ // If we are interpolated following, then reset physics interpolation
+ // when first appearing. This won't be called by canvas item, as in
+ // following mode, is_interpolated() is actually FALSE.
+ if (_interpolation_data.interpolated_follow) {
+ notification(NOTIFICATION_RESET_PHYSICS_INTERPOLATION);
+ }
}
if (p_what == NOTIFICATION_EXIT_TREE) {
@@ -1194,7 +1217,15 @@ void CPUParticles2D::_notification(int p_what) {
_update_internal(false);
}
if (p_what == NOTIFICATION_INTERNAL_PHYSICS_PROCESS) {
- _update_internal(true);
+ if (_interpolated) {
+ _update_internal(true);
+ }
+ if (_interpolation_data.interpolated_follow) {
+ // Keep the interpolated follow target updated.
+ DEV_CHECK_ONCE(!_interpolated);
+ _interpolation_data.global_xform_prev = _interpolation_data.global_xform_curr;
+ _interpolation_data.global_xform_curr = get_global_transform();
+ }
}
#ifdef GODOT_CPU_PARTICLES_2D_LEGACY_COMPATIBILITY
if (p_what == NOTIFICATION_TRANSFORM_CHANGED) {
@@ -1227,6 +1258,20 @@ void CPUParticles2D::_notification(int p_what) {
}
}
}
+#else
+ if (p_what == NOTIFICATION_TRANSFORM_CHANGED) {
+ if (_interpolation_data.interpolated_follow) {
+ // If the transform has been updated AFTER the physics tick, keep data flowing.
+ if (Engine::get_singleton()->is_in_physics_frame()) {
+ _interpolation_data.global_xform_curr = get_global_transform();
+ }
+ }
+ }
+ if (p_what == NOTIFICATION_RESET_PHYSICS_INTERPOLATION) {
+ // Make sure current is up to date with any pending global transform changes.
+ _interpolation_data.global_xform_curr = get_global_transform_const();
+ _interpolation_data.global_xform_prev = _interpolation_data.global_xform_curr;
+ }
#endif
}
@@ -1577,6 +1622,12 @@ CPUParticles2D::CPUParticles2D() {
set_color(Color(1, 1, 1, 1));
_update_mesh_texture();
+
+ // CPUParticles2D defaults to interpolation off.
+ // This is because the result often looks better when the particles are updated every frame.
+ // Note that children will need to explicitly turn back on interpolation if they want to use it,
+ // rather than relying on inherit mode.
+ set_physics_interpolation_mode(Node::PHYSICS_INTERPOLATION_MODE_OFF);
}
CPUParticles2D::~CPUParticles2D() {
diff --git a/scene/2d/cpu_particles_2d.h b/scene/2d/cpu_particles_2d.h
index daa94b40369..216b7b7f14a 100644
--- a/scene/2d/cpu_particles_2d.h
+++ b/scene/2d/cpu_particles_2d.h
@@ -200,8 +200,19 @@ private:
void _update_particle_data_buffer();
Mutex update_mutex;
+
+ // Whether this particle system is interpolated.
bool _interpolated = false;
+ struct InterpolationData {
+ // Whether this particle is non-interpolated, but following an interpolated parent.
+ bool interpolated_follow = false;
+
+ // If doing interpolated follow, we need to keep these updated per tick.
+ Transform2D global_xform_curr;
+ Transform2D global_xform_prev;
+ } _interpolation_data;
+
void _update_render_thread();
void _update_mesh_texture();
diff --git a/scene/main/node.cpp b/scene/main/node.cpp
index 274cfc25a51..99431068557 100644
--- a/scene/main/node.cpp
+++ b/scene/main/node.cpp
@@ -882,9 +882,7 @@ void Node::set_physics_interpolation_mode(PhysicsInterpolationMode p_mode) {
}
void Node::reset_physics_interpolation() {
- if (is_physics_interpolated_and_enabled()) {
- propagate_notification(NOTIFICATION_RESET_PHYSICS_INTERPOLATION);
- }
+ propagate_notification(NOTIFICATION_RESET_PHYSICS_INTERPOLATION);
}
float Node::get_physics_process_delta_time() const {