Properly scale radii for 2D parts shown in 3D space view's pinhole image plane

crates/re_space_view_spatial/src/contexts/mod.rs

@@ -23,6 +23,13 @@ use re_viewer_context::{
 /// Context objects for a single entity in a spatial scene.
 pub struct SpatialSceneEntityContext<'a> {
     pub world_from_entity: glam::Affine3A,
+
+    /// Scale factor to be applied on radii for 2D object drawn on a 3D space view's pinhole camera.
+    ///
+    /// `Some` when a parent pinhole transform exists for the entity (that isn't the space origin).
+    /// In this case the factor converts from the "pixel" unit of pinhole to the 3D pinhole widget
+    /// actual pixel size (taking into account the image plane distance).
+    pub radii_scale_factor: Option<f32>,
     pub depth_offset: DepthOffset,
     pub annotations: std::sync::Arc<Annotations>,
     pub shared_render_builders: &'a SharedRenderBuilders,

crates/re_space_view_spatial/src/parts/arrows3d.rs

@@ -88,7 +88,7 @@ impl Arrows3DPart {
             process_annotations::<Vector3D, Arrows3D>(query, arch_view, &ent_context.annotations)?;
 
         let colors = process_colors(arch_view, ent_path, &annotation_infos)?;
-        let radii = process_radii(arch_view, ent_path)?;
+        let radii = process_radii(arch_view, None, ent_path)?;
 
         if arch_view.num_instances() <= self.max_labels {
             // Max labels is small enough that we can afford iterating on the colors again.

crates/re_space_view_spatial/src/parts/boxes2d.rs

@@ -90,7 +90,7 @@ impl Boxes2DPart {
         let positions = arch_view
             .iter_optional_component::<Position2D>()?
             .map(|position| position.unwrap_or(Position2D::ZERO));
-        let radii = process_radii(arch_view, ent_path)?;
+        let radii = process_radii(arch_view, ent_context.radii_scale_factor, ent_path)?;
         let colors = process_colors(arch_view, ent_path, &annotation_infos)?;
 
         if arch_view.num_instances() <= self.max_labels {

crates/re_space_view_spatial/src/parts/boxes3d.rs

@@ -51,7 +51,7 @@ impl Boxes3DPart {
         let rotation = arch_view
             .iter_optional_component::<Rotation3D>()?
             .map(|position| position.unwrap_or(Rotation3D::IDENTITY));
-        let radii = process_radii(arch_view, ent_path)?;
+        let radii = process_radii(arch_view, None, ent_path)?;
         let colors = process_colors(arch_view, ent_path, &annotation_infos)?;
         let labels = process_labels(arch_view, &annotation_infos)?;
 

crates/re_space_view_spatial/src/parts/entity_iterator.rs

@@ -63,6 +63,7 @@ where
                 .per_entity
                 .get(&ent_path.hash())
                 .unwrap_or(&default_depth_offset),
+            radii_scale_factor: radii_scale_factor(ctx, query, transforms, ent_path),
             annotations: annotations.0.find(ent_path),
             shared_render_builders,
             highlight: query.highlights.entity_outline_mask(ent_path.hash()),
@@ -96,3 +97,30 @@ where
 
     Ok(())
 }
+
+fn radii_scale_factor(
+    ctx: &mut ViewerContext<'_>,
+    query: &ViewQuery<'_>,
+    transforms: &TransformContext,
+    ent_path: &EntityPath,
+) -> Option<f32> {
+    let pinhole_ent_path = transforms.parent_pinhole(ent_path)?;
+
+    let pinhole = crate::query_pinhole(
+        ctx.store_db.store(),
+        &query.latest_at_query(),
+        pinhole_ent_path,
+    )?;
+
+    let distance = *query
+        .entity_props_map
+        .get(pinhole_ent_path)
+        .pinhole_image_plane_distance
+        .get();
+
+    let focal_length = pinhole.focal_length_in_pixels();
+    let focal_length = glam::vec2(focal_length.x(), focal_length.y());
+    let scale = distance / focal_length;
+
+    Some(2.0 / (1.0 / scale.x + 1.0 / scale.y))
+}

crates/re_space_view_spatial/src/parts/lines2d.rs

@@ -91,7 +91,7 @@ impl Lines2DPart {
         )?;
 
         let colors = process_colors(arch_view, ent_path, &annotation_infos)?;
-        let radii = process_radii(arch_view, ent_path)?;
+        let radii = process_radii(arch_view, ent_context.radii_scale_factor, ent_path)?;
 
         if arch_view.num_instances() <= self.max_labels {
             // Max labels is small enough that we can afford iterating on the colors again.

crates/re_space_view_spatial/src/parts/lines3d.rs

@@ -97,7 +97,7 @@ impl Lines3DPart {
         )?;
 
         let colors = process_colors(arch_view, ent_path, &annotation_infos)?;
-        let radii = process_radii(arch_view, ent_path)?;
+        let radii = process_radii(arch_view, None, ent_path)?;
 
         if arch_view.num_instances() <= self.max_labels {
             // Max labels is small enough that we can afford iterating on the colors again.

crates/re_space_view_spatial/src/parts/mod.rs

@@ -162,16 +162,18 @@ pub fn process_labels<'a, A: Archetype>(
 /// where no radius is specified.
 pub fn process_radii<'a, A: Archetype>(
     arch_view: &'a re_query::ArchetypeView<A>,
+    radii_scale_factor: Option<f32>,
     ent_path: &EntityPath,
 ) -> Result<impl Iterator<Item = re_renderer::Size> + 'a, re_query::QueryError> {
     re_tracing::profile_function!();
+
     let ent_path = ent_path.clone();
     Ok(arch_view
         .iter_optional_component::<re_types::components::Radius>()?
         .map(move |radius| {
             radius.map_or(re_renderer::Size::AUTO, |r| {
                 if 0.0 <= r.0 && r.0.is_finite() {
-                    re_renderer::Size::new_scene(r.0)
+                    re_renderer::Size::new_scene(r.0 * radii_scale_factor.unwrap_or(1.0))
                 } else {
                     if r.0 < 0.0 {
                         re_log::warn_once!("Found negative radius in entity {ent_path}");

crates/re_space_view_spatial/src/parts/points2d.rs

@@ -86,7 +86,7 @@ impl Points2DPart {
             )?;
 
         let colors = process_colors(arch_view, ent_path, &annotation_infos)?;
-        let radii = process_radii(arch_view, ent_path)?;
+        let radii = process_radii(arch_view, ent_context.radii_scale_factor, ent_path)?;
 
         let positions = arch_view
             .iter_required_component::<Position2D>()?

crates/re_space_view_spatial/src/parts/points3d.rs

@@ -270,7 +270,7 @@ impl LoadedPoints {
         ent_path: &EntityPath,
     ) -> Result<Vec<re_renderer::Size>, QueryError> {
         re_tracing::profile_function!();
-        process_radii(arch_view, ent_path).map(|radii| {
+        process_radii(arch_view, None, ent_path).map(|radii| {
             re_tracing::profile_scope!("collect");
             radii.collect()
         })