diff --git a/crates/polymodel-renderer-worker/tests/ldraw_preview.rs b/crates/polymodel-renderer-worker/tests/ldraw_preview.rs
index 24a4446..fa79e5b 100644
--- a/crates/polymodel-renderer-worker/tests/ldraw_preview.rs
+++ b/crates/polymodel-renderer-worker/tests/ldraw_preview.rs
@@ -6,14 +6,56 @@ use std::process::Command;
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use polymodel_ldraw_core::{
-    AdapterRequest, CancellationPolicy, InProcessRustAdapter, Materialization, NormalizedPath,
-    ParserProfile, RootId,
+    AdapterRequest, CacheKey, CancellationPolicy, GeometryRecord, InProcessRustAdapter,
+    Materialization, NoopSemanticSink, NormalizedPath, ParserProfile, RootId, SemanticEvent,
+    SemanticSink,
 };
 use polymodel_renderer_worker::{
     LdrawLightingMaterialPolicy, official_materializations, parse_and_adapt_ldraw, preview_limits,
     scene_instance_batches, scene_mesh_topology,
 };
 
+#[derive(Default)]
+struct GeometryCollector {
+    geometry: std::collections::HashMap<CacheKey, Vec<GeometryRecord>>,
+}
+
+impl SemanticSink for GeometryCollector {
+    fn on_event(
+        &mut self,
+        event: &SemanticEvent<'_>,
+        _context: &polymodel_ldraw_core::TraversalContext,
+    ) {
+        if let SemanticEvent::GeometryEmitted {
+            source,
+            line_type,
+            colour,
+            vertices,
+            bfc,
+            texmap,
+            inverted,
+            primitive_id,
+            span,
+        } = event
+        {
+            self.geometry
+                .entry(source.clone())
+                .or_default()
+                .push(GeometryRecord {
+                    primitive_id: *primitive_id,
+                    source: source.clone(),
+                    span: *span,
+                    line_type: *line_type,
+                    colour: *colour,
+                    vertices: vertices.to_vec(),
+                    bfc: *bfc,
+                    texmap: texmap.cloned(),
+                    inverted: *inverted,
+                });
+        }
+    }
+}
+
 const OMR: &str = "crates/polymodel-ldraw-testkit/corpus/omr-10030-1.mpd";
 const PLATE_2_X_3: &str = "parts/3021.dat";
 
@@ -40,7 +82,8 @@ fn isolated_plate() -> IsolatedPlate {
     );
     let plate_key = plate.key();
     materializations.insert(0, plate);
-    let result = InProcessRustAdapter::parse_with_limits(
+    let mut sink = GeometryCollector::default();
+    let result = InProcessRustAdapter::parse_with_limits_and_sink(
         AdapterRequest {
             bytes: &bytes,
             profile: ParserProfile::Compatibility,
@@ -52,6 +95,7 @@ fn isolated_plate() -> IsolatedPlate {
             cancellation: CancellationPolicy::default(),
         },
         preview_limits(),
+        &mut sink,
     )
     .expect("official 3021.dat must parse with its real closure");
     let model = result
@@ -59,7 +103,7 @@ fn isolated_plate() -> IsolatedPlate {
         .iter()
         .find(|model| model.cache_key == plate_key)
         .expect("3021 CacheKey must own a parsed model");
-    let body = result
+    let body = sink
         .geometry
         .get(&model.cache_key)
         .into_iter()
@@ -215,7 +259,8 @@ fn assert_official_subpart_identity(part: &str, authored_target: &str, physical_
             Some("official-ldraw-library".into()),
         ),
     );
-    let result = InProcessRustAdapter::parse_with_limits(
+    let mut noop = NoopSemanticSink;
+    let result = InProcessRustAdapter::parse_with_limits_and_sink(
         AdapterRequest {
             bytes: &bytes,
             profile: ParserProfile::Compatibility,
@@ -227,6 +272,7 @@ fn assert_official_subpart_identity(part: &str, authored_target: &str, physical_
             cancellation: CancellationPolicy::default(),
         },
         preview_limits(),
+        &mut noop,
     )
     .expect("official parent must parse with its exact closure");
     let parsed_child = result
@@ -377,16 +423,21 @@ fn official_materializations_seed_ldconfig_colour_table() {
     );
     let root_key = root_materialization.key();
     materializations.insert(0, root_materialization);
-    let parsed = InProcessRustAdapter::parse(AdapterRequest {
-        bytes: root_bytes,
-        profile: ParserProfile::Compatibility,
-        provenance_id: "official-ldconfig-root",
-        root_name: path.as_str(),
-        root: RootId::OfficialLibrary,
-        materializations: &materializations,
-        target_selections: &closure.target_selections,
-        cancellation: CancellationPolicy::default(),
-    })
+    let mut noop = NoopSemanticSink;
+    let parsed = InProcessRustAdapter::parse_with_limits_and_sink(
+        AdapterRequest {
+            bytes: root_bytes,
+            profile: ParserProfile::Compatibility,
+            provenance_id: "official-ldconfig-root",
+            root_name: path.as_str(),
+            root: RootId::OfficialLibrary,
+            materializations: &materializations,
+            target_selections: &closure.target_selections,
+            cancellation: CancellationPolicy::default(),
+        },
+        preview_limits(),
+        &mut noop,
+    )
     .expect("model should parse with seeded LDConfig");
     parsed
         .models
@@ -510,7 +561,8 @@ fn pinned_scene() -> polymodel_renderer_protocol::scene::Scene {
     );
     materializations.insert(0, materialization);
     eprintln!("[ldraw-preview-test] parsing pinned OMR");
-    let result = InProcessRustAdapter::parse_with_limits(
+    let mut noop = NoopSemanticSink;
+    let result = InProcessRustAdapter::parse_with_limits_and_sink(
         AdapterRequest {
             bytes: &bytes,
             profile: ParserProfile::Compatibility,
@@ -522,6 +574,7 @@ fn pinned_scene() -> polymodel_renderer_protocol::scene::Scene {
             cancellation: CancellationPolicy::default(),
         },
         preview_limits(),
+        &mut noop,
     )
     .expect("pinned OMR must parse");
     eprintln!("[ldraw-preview-test] parse complete");