diff --git a/editor/src/import.rs b/editor/src/import.rs
new file mode 100644
index 0000000..93b0a2a
--- /dev/null
+++ b/editor/src/import.rs
@@ -0,0 +1,38 @@
+use crate::model;
+
+pub fn load_stl(path: std::path::PathBuf) -> model::Model {
+    let name = path.file_name().map(|v| v.to_string_lossy().to_string());
+
+    let mut file = std::fs::File::open(path).unwrap();
+    let stl = stl::read_stl(&mut file).unwrap();
+
+    let mut vertices = Vec::new();
+    let mut indices = Vec::new();
+
+    for tri in stl.triangles.iter() {
+        indices.push(vertices.len() as u32);
+        vertices.push(model::BasicVertex {
+            position: tri.v1.into(),
+        });
+        indices.push(vertices.len() as u32);
+        vertices.push(model::BasicVertex {
+            position: tri.v2.into(),
+        });
+        indices.push(vertices.len() as u32);
+        vertices.push(model::BasicVertex {
+            position: tri.v3.into(),
+        });
+    }
+
+    model::Model {
+        name: name.clone(),
+        objects: vec![model::Object {
+            name,
+            mesh: model::Mesh {
+                transform: Default::default(),
+                data: model::MeshData { vertices, indices },
+            },
+            children: vec![],
+        }],
+    }
+}
diff --git a/editor/src/main.rs b/editor/src/main.rs
index 498e1b6..0efdc3b 100644
--- a/editor/src/main.rs
+++ b/editor/src/main.rs
@@ -10,6 +10,8 @@ use egui_winit::winit::{
 use legion::EntityStore;
 use std::sync::Arc;
 
+mod import;
+mod model;
 mod render;
 mod ui;
 
@@ -107,7 +109,9 @@ impl Application {
                 Ok(ui::FileEvent::SaveAs(path)) => println!("Saving as: {:?}", path),
                 Ok(ui::FileEvent::Import(kind, path)) => match kind {
                     ui::ImportKind::Stl => {
-                        self.load_stl(path);
+                        let model = import::load_stl(path);
+                        let widgets = self.render_state.load_model(&model);
+                        self.objects.extend(widgets.into_iter());
                     }
                 },
                 Err(crossbeam_channel::TryRecvError::Empty) => break,
@@ -119,16 +123,7 @@ impl Application {
 
         for object in self.objects.iter_mut() {
             object.flush_dirty(|object| {
-                let translation = glam::Vec3::from_slice(&object.position);
-                let rotation = glam::Quat::from_euler(
-                    glam::EulerRot::XYZ,
-                    object.rotation[0],
-                    object.rotation[1],
-                    object.rotation[2],
-                );
-                let scale = glam::Vec3::splat(object.scale);
-                let transform =
-                    glam::Mat4::from_scale_rotation_translation(scale, rotation, translation);
+                let transform = object.transform.to_mat4();
                 self.render_state
                     .world
                     .entry_mut(object.entity)
@@ -140,89 +135,6 @@ impl Application {
         }
     }
 
-    pub fn load_stl(&mut self, path: std::path::PathBuf) {
-        let root_name = path
-            .file_name()
-            .map(|v| v.to_string_lossy().to_string())
-            .unwrap_or("<unnamed>".to_string());
-
-        use cyborg::pass::{
-            mesh::{Index, MeshPass, Vertex},
-            RenderPassBox,
-        };
-        use cyborg::storage::mesh::{AttrBuffer, MeshBuffer};
-
-        eprintln!("loading {:?}", path);
-
-        let mut file = std::fs::File::open(path).unwrap();
-        let stl = stl::read_stl(&mut file).unwrap();
-
-        let mut vertices = Vec::new();
-        let mut indices = Vec::new();
-
-        for tri in stl.triangles.iter() {
-            let tan_frame = 0; // TODO make from normal
-            indices.push(vertices.len() as Index);
-            vertices.push(Vertex {
-                position: tri.v1,
-                tan_frame,
-            });
-            indices.push(vertices.len() as Index);
-            vertices.push(Vertex {
-                position: tri.v2,
-                tan_frame,
-            });
-            indices.push(vertices.len() as Index);
-            vertices.push(Vertex {
-                position: tri.v3,
-                tan_frame,
-            });
-        }
-
-        let mesh_pass = self
-            .render_state
-            .resources
-            .get::<RenderPassBox<MeshPass>>()
-            .unwrap();
-        let attributes = mesh_pass.get_attributes();
-
-        let vertices = AttrBuffer {
-            id: attributes.vertex,
-            count: vertices.len(),
-            data: bytemuck::cast_slice(&vertices).to_vec(),
-        };
-
-        let indices = AttrBuffer {
-            id: attributes.index,
-            count: indices.len(),
-            data: bytemuck::cast_slice(&indices).to_vec(),
-        };
-
-        let mut mesh = MeshBuffer::default();
-        mesh.attributes.push(vertices);
-        mesh.attributes.push(indices);
-
-        let entity = self.render_state.world.push((
-            cyborg::scene::Mesh {
-                mesh: mesh_pass.get_mesh_pool().load(mesh).unwrap(),
-            },
-            cyborg::scene::Transform {
-                transform: Default::default(),
-            },
-        ));
-
-        let object = ui::ObjectWidget {
-            name: root_name,
-            position: [0.0; 3],
-            rotation: [0.0; 3],
-            scale: 1.0,
-            entity,
-            dirty: false,
-        };
-
-        self.objects.push(object);
-    }
-
     pub fn on_resize(&mut self, new_size: PhysicalSize<u32>) {
         if new_size.width > 0 && new_size.height > 0 {
             self.size = new_size;
diff --git a/editor/src/model.rs b/editor/src/model.rs
new file mode 100644
index 0000000..46ee0e8
--- /dev/null
+++ b/editor/src/model.rs
@@ -0,0 +1,55 @@
+pub struct Model {
+    pub name: Option<String>,
+    pub objects: Vec<Object>,
+}
+
+pub struct Object {
+    pub name: Option<String>,
+    pub mesh: Mesh,
+    pub children: Vec<Object>,
+}
+
+pub struct Mesh {
+    pub transform: Transform,
+    pub data: MeshData,
+}
+
+pub struct MeshData {
+    pub vertices: Vec<BasicVertex>,
+    pub indices: Vec<u32>,
+}
+
+pub struct BasicVertex {
+    pub position: glam::Vec3,
+}
+
+#[derive(Copy, Clone, Debug)]
+pub struct Transform {
+    pub position: glam::Vec3,
+    pub rotation: glam::Vec3, // TODO support glam::Quat too
+    pub scale: f32,
+}
+
+impl Transform {
+    pub fn to_mat4(&self) -> glam::Mat4 {
+        let translation = self.position;
+        let rotation = glam::Quat::from_euler(
+            glam::EulerRot::XYZ,
+            self.rotation[0],
+            self.rotation[1],
+            self.rotation[2],
+        );
+        let scale = glam::Vec3::splat(self.scale);
+        glam::Mat4::from_scale_rotation_translation(scale, rotation, translation)
+    }
+}
+
+impl Default for Transform {
+    fn default() -> Self {
+        Self {
+            position: glam::Vec3::ZERO,
+            rotation: glam::Vec3::ZERO,
+            scale: 1.0,
+        }
+    }
+}
diff --git a/editor/src/render.rs b/editor/src/render.rs
index 070dc23..bd61531 100644
--- a/editor/src/render.rs
+++ b/editor/src/render.rs
@@ -1,6 +1,8 @@
-use crate::ui::ViewportWidget;
+use crate::model;
+use crate::ui::{ObjectWidget, ViewportWidget};
 use crate::wgpu;
 use cyborg::camera::Camera;
+use cyborg::storage::mesh::MeshHandle;
 use cyborg::viewport::{Viewport, ViewportInfo, ViewportViews};
 use std::sync::Arc;
 
@@ -258,4 +260,77 @@ impl RenderState {
         self.render_schedule
             .execute(&mut self.world, &mut self.resources);
     }
+
+    pub fn load_model(&mut self, model: &model::Model) -> Vec<ObjectWidget> {
+        // TODO use model name?
+        let mut objects = Vec::new();
+        for object in model.objects.iter() {
+            objects.push(self.load_object(object));
+        }
+
+        objects
+    }
+
+    pub fn load_object(&mut self, object: &model::Object) -> ObjectWidget {
+        let mesh = self.load_mesh_data(&object.mesh.data);
+
+        let entity = self.world.push((
+            cyborg::scene::Mesh { mesh },
+            cyborg::scene::Transform {
+                transform: object.mesh.transform.to_mat4(),
+            },
+        ));
+
+        let mut children = Vec::new();
+        for child in object.children.iter() {
+            children.push(self.load_object(child));
+        }
+
+        ObjectWidget {
+            name: object.name.clone(),
+            transform: object.mesh.transform.clone(),
+            entity,
+            children,
+            dirty: false,
+            children_dirty: false,
+        }
+    }
+
+    pub fn load_mesh_data(&mut self, data: &model::MeshData) -> MeshHandle {
+        use cyborg::pass::{
+            mesh::{MeshPass, Vertex},
+            RenderPassBox,
+        };
+        use cyborg::storage::mesh::{AttrBuffer, MeshBuffer};
+
+        let mesh_pass = self.resources.get::<RenderPassBox<MeshPass>>().unwrap();
+        let attributes = mesh_pass.get_attributes();
+
+        let vertices: Vec<_> = data
+            .vertices
+            .iter()
+            .map(|v| Vertex {
+                position: v.position.to_array(),
+                tan_frame: 0, // TODO encode tangents
+            })
+            .collect();
+
+        let vertices = AttrBuffer {
+            id: attributes.vertex,
+            count: vertices.len(),
+            data: bytemuck::cast_slice(&vertices).to_vec(),
+        };
+
+        let indices = AttrBuffer {
+            id: attributes.index,
+            count: data.indices.len(),
+            data: bytemuck::cast_slice(&data.indices).to_vec(),
+        };
+
+        let mut mesh = MeshBuffer::default();
+        mesh.attributes.push(vertices);
+        mesh.attributes.push(indices);
+
+        mesh_pass.get_mesh_pool().load(mesh).unwrap()
+    }
 }
diff --git a/editor/src/ui.rs b/editor/src/ui.rs
index 678c68e..fe01817 100644
--- a/editor/src/ui.rs
+++ b/editor/src/ui.rs
@@ -202,8 +202,8 @@ impl UserInterface {
         egui::SidePanel::left("objects_panel")
             .resizable(true)
             .show(ctx, |ui| {
-                for object in objects.iter_mut() {
-                    object.ui(ui);
+                for (index, object) in objects.iter_mut().enumerate() {
+                    object.ui(index, ui);
                 }
             });
 
@@ -299,20 +299,28 @@ impl egui::Widget for &mut ViewportWidget {
 }
 
 pub struct ObjectWidget {
-    pub name: String,
-    pub position: [f32; 3],
-    pub rotation: [f32; 3],
-    pub scale: f32,
+    pub name: Option<String>,
+    pub transform: crate::model::Transform,
     pub entity: legion::Entity,
+    pub children: Vec<ObjectWidget>,
     pub dirty: bool,
+    pub children_dirty: bool,
 }
 
 impl ObjectWidget {
-    pub fn ui(&mut self, ui: &mut egui::Ui) {
-        egui::CollapsingHeader::new(&self.name)
+    pub fn ui(&mut self, index: usize, ui: &mut egui::Ui) {
+        egui::CollapsingHeader::new(self.name.as_ref().unwrap_or(&"<unnamed>".into()))
+            .id_source(format!("child_{}", index))
             .default_open(true)
             .show(ui, |ui| {
                 self.ui_self(ui);
+
+                for (index, child) in self.children.iter_mut().enumerate() {
+                    child.ui(index, ui);
+                    if child.dirty {
+                        self.children_dirty = true;
+                    }
+                }
             });
     }
 
@@ -336,26 +344,47 @@ impl ObjectWidget {
     }
 
     pub fn ui_position(&mut self, ui: &mut egui::Ui) {
-        let speed = 0.1 * self.scale;
-        for axis in self.position.iter_mut() {
-            let drag = egui::DragValue::new(axis).speed(speed);
-            if ui.add(drag).changed() {
-                self.dirty = true;
-            }
+        let speed = 0.1 * self.transform.scale;
+        if Self::ui_vec3(ui, speed, &mut self.transform.position) {
+            self.dirty = true;
         }
     }
 
     pub fn ui_rotation(&mut self, ui: &mut egui::Ui) {
-        for axis in self.rotation.iter_mut() {
-            if ui.drag_angle(axis).changed() {
-                self.dirty = true;
-            }
+        let axes = &mut self.transform.rotation;
+
+        if ui.drag_angle(&mut axes.x).changed() {
+            self.dirty = true;
+        }
+
+        if ui.drag_angle(&mut axes.y).changed() {
+            self.dirty = true;
+        }
+
+        if ui.drag_angle(&mut axes.z).changed() {
+            self.dirty = true;
         }
     }
 
+    pub fn ui_vec3(ui: &mut egui::Ui, speed: f32, vec3: &mut glam::Vec3) -> bool {
+        let x_drag = egui::DragValue::new(&mut vec3.x).speed(speed);
+        let dirty = ui.add(x_drag).changed();
+
+        let dirty = dirty || {
+            // For some reason, Rust complains if this isn't in a block
+            let y_drag = egui::DragValue::new(&mut vec3.y).speed(speed);
+            ui.add(y_drag).changed()
+        };
+
+        let z_drag = egui::DragValue::new(&mut vec3.z).speed(speed);
+        let dirty = dirty || ui.add(z_drag).changed();
+
+        dirty
+    }
+
     pub fn ui_scale(&mut self, ui: &mut egui::Ui) {
-        let scale_speed = self.scale * 0.01;
-        let drag = egui::DragValue::new(&mut self.scale)
+        let scale_speed = self.transform.scale * 0.01;
+        let drag = egui::DragValue::new(&mut self.transform.scale)
             .clamp_range(0.0..=f32::INFINITY)
             .speed(scale_speed);
         if ui.add(drag).changed() {
@@ -364,9 +393,20 @@ impl ObjectWidget {
     }
 
     pub fn flush_dirty(&mut self, mut f: impl FnMut(&mut Self)) {
-        if self.dirty {
-            f(self);
-            self.dirty = false;
+        let mut stack = vec![self];
+        if let Some(parent) = stack.pop() {
+            if parent.dirty {
+                parent.dirty = false;
+                f(parent);
+            }
+
+            if parent.children_dirty {
+                parent.children_dirty = false;
+
+                for child in parent.children.iter_mut() {
+                    stack.push(child);
+                }
+            }
         }
     }
 }