diff --git a/packages/scene-graph/src/index.ts b/packages/scene-graph/src/index.ts
index a90d60d3d..74bb220f8 100644
--- a/packages/scene-graph/src/index.ts
+++ b/packages/scene-graph/src/index.ts
@@ -1,6 +1,9 @@
 export * from './images'
 export * from './snap'
 export * from './export-scale'
+export * from './geometry'
+export { default as TransformMatrix } from './matrix'
+export type { Mat3 } from './matrix'
 export { UndoManager, type UndoEntry, type UndoManagerOptions } from './undo'
 
 import { omit } from 'es-toolkit/object'
@@ -128,7 +131,6 @@ export class SceneGraph {
     }
     return count
   }
-  // --- Variables ---
   addVariable(variable: Variable): void {
     Variables.addVariable(this, variable)
   }
@@ -415,7 +417,6 @@ export class SceneGraph {
     const oldParentId = node.parentId
     this.absPosCache.clear()
 
-    // Convert absolute position
     const absPos = this.getAbsolutePosition(nodeId)
     const newParentNode = this.nodes.get(newParentId)
     const newParentAbs =
@@ -423,16 +424,13 @@ export class SceneGraph {
         ? { x: 0, y: 0 }
         : this.getAbsolutePosition(newParentId)
 
-    // Remove from old parent
     if (oldParent) {
       oldParent.childIds = oldParent.childIds.filter((cid) => cid !== nodeId)
     }
 
-    // Add to new parent
     node.parentId = newParentId
     newParent.childIds.push(nodeId)
 
-    // Adjust position so node stays in same visual place
     node.x = absPos.x - newParentAbs.x
     node.y = absPos.y - newParentAbs.y
 
diff --git a/tests/engine/geometry/angles.test.ts b/tests/engine/geometry/angles.test.ts
index 250a8b7b2..8da2b8e67 100644
--- a/tests/engine/geometry/angles.test.ts
+++ b/tests/engine/geometry/angles.test.ts
@@ -1,6 +1,6 @@
 import { describe, test, expect } from 'bun:test'
 
-import { degToRad, radToDeg } from '@open-pencil/core'
+import { degToRad, radToDeg } from '@open-pencil/scene-graph'
 
 describe('degToRad / radToDeg', () => {
   test('degToRad converts degrees to radians', () => {
diff --git a/tests/engine/geometry/bounds.test.ts b/tests/engine/geometry/bounds.test.ts
index 200a1f2a3..5d4ce7803 100644
--- a/tests/engine/geometry/bounds.test.ts
+++ b/tests/engine/geometry/bounds.test.ts
@@ -1,6 +1,6 @@
 import { describe, test, expect } from 'bun:test'
 
-import { computeAbsoluteBounds, computeBounds, type Vector } from '@open-pencil/core'
+import { computeAbsoluteBounds, computeBounds, type Vector } from '@open-pencil/scene-graph'
 
 describe('computeBounds', () => {
   test('empty iterable returns zero rect', () => {
diff --git a/tests/engine/geometry/matrix.test.ts b/tests/engine/geometry/matrix.test.ts
index cf791c830..88ec6a0a0 100644
--- a/tests/engine/geometry/matrix.test.ts
+++ b/tests/engine/geometry/matrix.test.ts
@@ -7,7 +7,7 @@
  */
 import { describe, test, expect } from 'bun:test'
 
-import { TransformMatrix } from '@open-pencil/core'
+import { TransformMatrix } from '@open-pencil/scene-graph'
 
 import { expectDefined } from '#tests/helpers/assert'
 
diff --git a/tests/engine/geometry/rotation.test.ts b/tests/engine/geometry/rotation.test.ts
index 8899275b9..1e181872d 100644
--- a/tests/engine/geometry/rotation.test.ts
+++ b/tests/engine/geometry/rotation.test.ts
@@ -1,6 +1,6 @@
 import { describe, test, expect } from 'bun:test'
 
-import { rotatePoint, rotatedBBox, rotatedCorners } from '@open-pencil/core'
+import { rotatePoint, rotatedBBox, rotatedCorners } from '@open-pencil/scene-graph'
 
 describe('rotatePoint', () => {
   test('no rotation returns same point', () => {