center coordinate system of renderer at player camera

this avoids rendering glitches when camera is far away from the center
of the coordinate system.

src/commands.rs

@@ -34,7 +34,7 @@ struct ParserState {
 
     // Actor fields
     id: String,
-    pos: Vec3,
+    pos: DVec3,
     model: String,
     model_scale: f32,
     rotation: Quat,
@@ -84,7 +84,7 @@ impl Default for ParserState {
             chat: "".to_string(),
 
             id: "".to_string(),
-            pos: Vec3::new(0.0, 0.0, 0.0),
+            pos: DVec3::new(0.0, 0.0, 0.0),
             model: "".to_string(),
             model_scale: 1.0,
             rotation: Quat::IDENTITY,
@@ -205,8 +205,8 @@ pub fn load_defs(
                 state.class = DefClass::Actor;
                 state.model = model.to_string();
                 if let (Ok(x_float), Ok(y_float), Ok(z_float)) =
-                        (x.parse::<f32>(), y.parse::<f32>(), z.parse::<f32>()) {
+                        (x.parse::<f64>(), y.parse::<f64>(), z.parse::<f64>()) {
-                    state.pos = Vec3::new(x_float, y_float, z_float);
+                    state.pos = DVec3::new(x_float, y_float, z_float);
                 }
                 else {
                     error!("Can't parse coordinates as floats in def: {line}");
@@ -506,6 +506,8 @@ fn spawn_entities(
                 camdistance: state.camdistance,
                 ..default()
             });
+            actor.insert(Position::from(state.pos));
+            actor.insert(Rotation::from(state.rotation));
             if state.is_sphere {
                 let sphere_texture_handle: Handle<Image> = asset_server.load(format!("textures/{}.jpg", state.model));
                 let sphere_handle = meshes.add(Sphere::default().mesh().uv(128, 128));
@@ -519,18 +521,16 @@ fn spawn_entities(
                     mesh: sphere_handle,
                     material: sphere_material_handle,
                     transform: Transform {
-                        translation: state.pos,
                         scale: Vec3::splat(state.model_scale),
-                        rotation: state.rotation,
+                        ..default()
                     },
                     ..default()
                 });
             } else {
                 actor.insert(SceneBundle {
                     transform: Transform {
-                        translation: state.pos,
                         scale: Vec3::splat(state.model_scale),
-                        rotation: state.rotation,
+                        ..default()
                     },
                     scene: asset_server.load(world::asset_name_to_path(state.model.as_str())),
                     ..default()
@@ -582,11 +582,6 @@ fn spawn_entities(
                         radius: 100.0,
                         ..default()
                     },
-                    transform: Transform {
-                        translation: state.pos,
-                        scale: Vec3::splat(state.model_scale),
-                        rotation: state.rotation,
-                    },
                     ..default()
                 });
             }

src/world.rs

@@ -4,6 +4,7 @@ use bevy::pbr::CascadeShadowConfigBuilder;
 use bevy::render::render_resource::{AsBindGroup, ShaderRef};
 use bevy::math::DVec3;
 use bevy_xpbd_3d::prelude::*;
+use bevy_xpbd_3d::plugins::sync::SyncConfig;
 use std::f32::consts::PI;
 
 const ASTEROID_SIZE: f32 = 100.0;
@@ -35,6 +36,14 @@ impl Plugin for WorldPlugin {
         app.add_plugins(MaterialPlugin::<RingMaterial>::default());
         //app.add_plugins(PhysicsDebugPlugin::default());
         app.insert_resource(Gravity(DVec3::splat(0.0)));
+
+        // Disable bevy_xpbd's position->transform sync because we have a
+        // custom syncing function.
+        app.insert_resource(SyncConfig {
+            position_to_transform: false,
+            transform_to_position: false,
+        });
+        app.add_systems(PreUpdate, position_to_transform);
     }
 }
 
@@ -153,17 +162,19 @@ pub fn setup(
     // Add shaded ring
     let ring_radius = 640000.0;
     let jupiter_radius = 200000.0;
-    commands.spawn(MaterialMeshBundle {
+    commands.spawn((
+        MaterialMeshBundle {
             mesh: meshes.add(Mesh::from(Cylinder::new(ring_radius, 1.0))),
-        transform: Transform::from_xyz(300000.0, -1000.0, 500000.0)
-            .with_rotation(Quat::from_rotation_z(1f32.to_radians())),
             material: materials_custom.add(RingMaterial {
                 alpha_mode: AlphaMode::Blend,
                 ring_radius: ring_radius,
                 jupiter_radius: jupiter_radius,
             }),
             ..default()
-    });
+        },
+        Position::from_xyz(300000.0, -1000.0, 500000.0),
+        Rotation::from(Quat::from_rotation_z(1f32.to_radians())),
+    ));
 
     // Add Light from the Sun
     commands.spawn(DirectionalLightBundle {
@@ -185,23 +196,23 @@ pub fn setup(
 
 fn handle_cheats(
     key_input: Res<ButtonInput<KeyCode>>,
-    mut q_player: Query<(&mut Transform, &mut LinearVelocity), With<actor::PlayerCamera>>,
+    mut q_player: Query<(&Transform, &mut Position, &mut LinearVelocity), With<actor::PlayerCamera>>,
     mut q_life: Query<(&mut actor::LifeForm, ), With<actor::Player>>,
     settings: ResMut<settings::Settings>,
 ) {
     if !settings.dev_mode || q_player.is_empty() || q_life.is_empty() {
         return;
     }
-    let (mut trans, mut v) = q_player.get_single_mut().unwrap();
+    let (trans, mut pos, mut v) = q_player.get_single_mut().unwrap();
     let (mut lifeform, ) = q_life.get_single_mut().unwrap();
     if key_input.just_pressed(settings.key_cheat_pizza) {
-        trans.translation = Vec3::new(-3370.0, 0.0, 0.0);
+        pos.0 = DVec3::new(-3370.0, 0.0, 0.0);
     }
     if key_input.just_pressed(settings.key_cheat_farview1) {
-        trans.translation = Vec3::new(-800000.0, 800000.0, 0.0);
+        pos.0 = DVec3::new(-800000.0, 800000.0, 0.0);
     }
     if key_input.just_pressed(settings.key_cheat_farview2) {
-        trans.translation = Vec3::new(800000.0, 400000.0, 0.0);
+        pos.0 = DVec3::new(800000.0, 400000.0, 0.0);
     }
     if key_input.just_pressed(settings.key_cheat_stop) {
         v.0 = DVec3::ZERO;
@@ -219,3 +230,22 @@ fn handle_cheats(
         lifeform.adrenaline = 1.0;
     }
 }
+
+// A variant of bevy_xpbd_3d::plugins::position_to_transform that adjusts
+// the rendering position to center entities at the player camera.
+// This avoids rendering glitches when very far away from the origin.
+pub fn position_to_transform(
+    q_player: Query<&Position, With<actor::PlayerCamera>>,
+    mut q_trans: Query<(&mut Transform, &Position, &Rotation)>,
+) {
+    if let Ok(player_pos) = q_player.get_single() {
+        for (mut transform, pos, rot) in &mut q_trans {
+                transform.translation = Vec3::new(
+                    (pos.x - player_pos.x) as f32,
+                    (pos.y - player_pos.y) as f32,
+                    (pos.z - player_pos.z) as f32,
+                );
+                transform.rotation = rot.as_quat();
+        }
+    }
+}