diff --git a/packages/viewer/src/lib/materials.test.ts b/packages/viewer/src/lib/materials.test.ts
new file mode 100644
index 00000000..57d170eb
--- /dev/null
+++ b/packages/viewer/src/lib/materials.test.ts
@@ -0,0 +1,32 @@
+// @ts-expect-error — bun:test is provided by the Bun runtime; viewer does not
+// depend on @types/bun so the import type is unresolved at compile time.
+import { describe, expect, test } from 'bun:test'
+import type { MaterialSchema } from '@pascal-app/core'
+import { getTextureKey, resolveTextureRepeat } from './materials'
+
+function materialWithRepeat(repeat: unknown): MaterialSchema {
+  return {
+    texture: {
+      url: 'https://example.com/texture.png',
+      repeat,
+    },
+  } as unknown as MaterialSchema
+}
+
+describe('legacy texture repeat values', () => {
+  test('normalizes tuple, scalar, and Vector2-shaped repeats', () => {
+    expect(resolveTextureRepeat([2, 3], undefined)).toEqual([2, 3])
+    expect(resolveTextureRepeat(2, undefined)).toEqual([2, 2])
+    expect(resolveTextureRepeat({ x: 2, y: 3 }, undefined)).toEqual([2, 3])
+  })
+
+  test('falls back to scale for malformed repeats', () => {
+    expect(resolveTextureRepeat({ width: 2 }, 4)).toEqual([4, 4])
+  })
+
+  test('keeps distinct Vector2-shaped repeats in distinct cache entries', () => {
+    expect(getTextureKey(materialWithRepeat({ x: 2, y: 3 }))).not.toBe(
+      getTextureKey(materialWithRepeat({ x: 4, y: 5 })),
+    )
+  })
+})
diff --git a/packages/viewer/src/lib/materials.ts b/packages/viewer/src/lib/materials.ts
index c150139d..504e3034 100644
--- a/packages/viewer/src/lib/materials.ts
+++ b/packages/viewer/src/lib/materials.ts
@@ -180,12 +180,28 @@ function getCacheKey(props: MaterialProperties, shading: RenderShading): string
   return `${shading}-${props.color}-${props.roughness}-${props.metalness}-${props.opacity}-${props.transparent}-${props.side}`
 }
 
-function getTextureKey(material?: MaterialSchema): string {
+function isFiniteNumber(value: unknown): value is number {
+  return typeof value === 'number' && Number.isFinite(value)
+}
+
+export function resolveTextureRepeat(repeat: unknown, scale: unknown): [number, number] {
+  const fallback = isFiniteNumber(scale) ? scale : 1
+  if (Array.isArray(repeat) && isFiniteNumber(repeat[0]) && isFiniteNumber(repeat[1])) {
+    return [repeat[0], repeat[1]]
+  }
+  if (isFiniteNumber(repeat)) return [repeat, repeat]
+  if (repeat && typeof repeat === 'object' && 'x' in repeat && 'y' in repeat) {
+    const { x, y } = repeat
+    if (isFiniteNumber(x) && isFiniteNumber(y)) return [x, y]
+  }
+  return [fallback, fallback]
+}
+
+export function getTextureKey(material?: MaterialSchema): string {
   const texture = material?.texture
   if (!texture) return 'none'
-  const repeat = texture.repeat?.join('x') ?? 'default'
-  const scale = texture.scale ?? 'default'
-  return `${texture.url}-${repeat}-${scale}`
+  const [repeatX, repeatY] = resolveTextureRepeat(texture.repeat, texture.scale)
+  return `${texture.url}-${repeatX}x${repeatY}`
 }
 
 function getTexture(material?: MaterialSchema): THREE.Texture | undefined {
@@ -200,8 +216,7 @@ function getTexture(material?: MaterialSchema): THREE.Texture | undefined {
   texture.wrapS = THREE.RepeatWrapping
   texture.wrapT = THREE.RepeatWrapping
 
-  const repeatX = textureConfig.repeat?.[0] ?? textureConfig.scale ?? 1
-  const repeatY = textureConfig.repeat?.[1] ?? textureConfig.scale ?? 1
+  const [repeatX, repeatY] = resolveTextureRepeat(textureConfig.repeat, textureConfig.scale)
   texture.repeat.set(repeatX, repeatY)
   texture.updateMatrix()
   texture.colorSpace = THREE.SRGBColorSpace