Reconstruct constant-section meshes as parametric solids

crates/doc/src/eval.rs

@@ -3299,6 +3299,20 @@ fn eval_feature(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature, st:
             }
             Ok(())
         }
+        FeatureKind::MeshConvert { body, tolerance } => {
+            let tolerance = val(vals, tolerance, Kind::Length)?;
+            let index = st.bodies.iter().position(|b| &b.name == body).ok_or_else(|| DocError::Unknown(format!("body `{body}`")))?;
+            let source = st.bodies.get(index).ok_or_else(|| DocError::Unknown(format!("body `{body}`")))?;
+            if doc.model_body_component(source) != f.component {
+                return Err(DocError::Invalid("activate the mesh body's component before converting it".into()));
+            }
+            let converted = kernel::convert_prismatic_mesh(&source.body, tolerance)?;
+            let converted = converted.with_color(source.body.color());
+            let result = ModelBody::new(source.name.clone(), converted, f.id);
+            let target = st.bodies.get_mut(index).ok_or_else(|| DocError::Unknown(format!("body `{body}`")))?;
+            *target = result;
+            Ok(())
+        }
         FeatureKind::MeshImport { meshes, .. } => {
             for (k, (name, b)) in mesh_bodies(meshes)?.into_iter().enumerate() {
                 let name = copy_body_name(st, f, k, &name);