Blueprint tree always starts at the origin now, "projected" paths are…

… called out explicitely (#5342)

### What

* Direct follow up of #5326
* Fixes #4156 


https://github.com/rerun-io/rerun/assets/1220815/77ed6a42-50db-4ca3-b596-8dcf5bce9baf


Follows the design proposal from the ticket directly. Some detail
decisions on how things are exactly handled, but code should be a bit
more composable now (albeit admittedly still a bit messy)

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using newly built examples:
[app.rerun.io](https://app.rerun.io/pr/5342/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/5342/index.html?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[app.rerun.io](https://app.rerun.io/pr/5342/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/5342)
- [Docs
preview](https://rerun.io/preview/6011f651a1ebd432d77d25d3edd7ea746053fd99/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/6011f651a1ebd432d77d25d3edd7ea746053fd99/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

crates/re_data_ui/src/item_ui.rs

@@ -409,6 +409,11 @@ pub fn instance_hover_card_ui(
     store: &re_data_store::DataStore,
     instance_path: &InstancePath,
 ) {
+    if !ctx.entity_db.is_known_entity(&instance_path.entity_path) {
+        ui.label("Unknown entity.");
+        return;
+    }
+
     let subtype_string = if instance_path.instance_key.is_splat() {
         "Entity"
     } else {

crates/re_space_view/src/data_query_blueprint.rs

@@ -337,13 +337,13 @@ impl<'a> QueryExpressionEvaluator<'a> {
         // Ignore empty nodes.
         // Since we recurse downwards, this prunes any branches that don't have anything to contribute to the scene
         // and aren't directly included.
-        let direct_included = self.entity_path_filter.is_exact_included(entity_path);
-        if direct_included || !children.is_empty() || !visualizers.is_empty() {
+        let exact_included = self.entity_path_filter.is_exact_included(entity_path);
+        if exact_included || !children.is_empty() || !visualizers.is_empty() {
             Some(data_results.insert(DataResultNode {
                 data_result: DataResult {
                     entity_path: entity_path.clone(),
                     visualizers,
-                    direct_included,
+                    direct_included: self.entity_path_filter.is_included(entity_path),
                     property_overrides: None,
                 },
                 children,

crates/re_space_view/src/space_view.rs

@@ -386,15 +386,14 @@ impl SpaceViewBlueprint {
         {
             re_tracing::profile_scope!("per_system_data_results");
 
-            query_result.tree.visit(&mut |handle| {
-                if let Some(result) = query_result.tree.lookup_result(handle) {
-                    for system in &result.visualizers {
-                        per_system_entities
-                            .entry(*system)
-                            .or_default()
-                            .insert(result.entity_path.clone());
-                    }
+            query_result.tree.visit(&mut |node| {
+                for system in &node.data_result.visualizers {
+                    per_system_entities
+                        .entry(*system)
+                        .or_default()
+                        .insert(node.data_result.entity_path.clone());
                 }
+                true
             });
         }
 

crates/re_viewer/src/ui/space_view_space_origin_ui.rs

@@ -125,7 +125,7 @@ fn space_view_space_origin_widget_editing_ui(
         selected_suggestion = selected_suggestion
             .saturating_add(arrow_down)
             .saturating_sub(arrow_up);
-        if !space_view_suggestions.is_empty() {
+        if !space_view_suggestions.is_empty() && !filtered_space_view_suggestions.is_empty() {
             selected_suggestion =
                 selected_suggestion.at_most(filtered_space_view_suggestions.len() - 1);
         }

crates/re_viewer_context/src/query_context.rs

@@ -113,28 +113,42 @@ impl DataResultTree {
     }
 
     /// Depth-first traversal of the tree, calling `visitor` on each result.
-    pub fn visit(&self, visitor: &mut impl FnMut(DataResultHandle)) {
+    ///
+    /// Stops traversing a branch if `visitor` returns `false`.
+    pub fn visit<'a>(&'a self, visitor: &mut impl FnMut(&'a DataResultNode) -> bool) {
         if let Some(root_handle) = self.root_handle {
             self.visit_recursive(root_handle, visitor);
         }
     }
 
     /// Look up a [`DataResult`] in the tree based on its handle.
+    #[inline]
     pub fn lookup_result(&self, handle: DataResultHandle) -> Option<&DataResult> {
         self.data_results.get(handle).map(|node| &node.data_result)
     }
 
     /// Look up a [`DataResultNode`] in the tree based on its handle.
+    #[inline]
     pub fn lookup_node(&self, handle: DataResultHandle) -> Option<&DataResultNode> {
         self.data_results.get(handle)
     }
 
     /// Look up a [`DataResultNode`] in the tree based on its handle.
+    #[inline]
     pub fn lookup_node_mut(&mut self, handle: DataResultHandle) -> Option<&mut DataResultNode> {
         self.data_results.get_mut(handle)
     }
 
     /// Look up a [`DataResultNode`] in the tree based on an [`EntityPath`].
+    #[inline]
+    pub fn lookup_node_by_path(&self, path: &EntityPath) -> Option<&DataResultNode> {
+        self.data_results_by_path
+            .get(&path.hash())
+            .and_then(|handle| self.lookup_node(*handle))
+    }
+
+    /// Look up a [`DataResult`] in the tree based on an [`EntityPath`].
+    #[inline]
     pub fn lookup_result_by_path(&self, path: &EntityPath) -> Option<&DataResult> {
         self.data_results_by_path
             .get(&path.hash())
@@ -146,16 +160,16 @@ impl DataResultTree {
         self.data_results_by_path.is_empty()
     }
 
-    fn visit_recursive(
-        &self,
+    fn visit_recursive<'a>(
+        &'a self,
         handle: DataResultHandle,
-        visitor: &mut impl FnMut(DataResultHandle),
+        visitor: &mut impl FnMut(&'a DataResultNode) -> bool,
     ) {
         if let Some(result) = self.data_results.get(handle) {
-            visitor(handle);
-
-            for child in &result.children {
-                self.visit_recursive(*child, visitor);
+            if visitor(result) {
+                for child in &result.children {
+                    self.visit_recursive(*child, visitor);
+                }
             }
         }
     }

crates/re_viewport/src/system_execution.rs

@@ -110,15 +110,14 @@ pub fn execute_systems_for_space_view<'a>(
     {
         re_tracing::profile_scope!("per_system_data_results");
 
-        query_result.tree.visit(&mut |handle| {
-            if let Some(result) = query_result.tree.lookup_result(handle) {
-                for system in &result.visualizers {
-                    per_system_data_results
-                        .entry(*system)
-                        .or_default()
-                        .push(result);
-                }
+        query_result.tree.visit(&mut |node| {
+            for system in &node.data_result.visualizers {
+                per_system_data_results
+                    .entry(*system)
+                    .or_default()
+                    .push(&node.data_result);
             }
+            true
         });
     }