diff --git a/optuna_dashboard/ts/components/ModelViewer.tsx b/optuna_dashboard/ts/components/ModelViewer.tsx
index 5f0d00bc..d1fc234d 100644
--- a/optuna_dashboard/ts/components/ModelViewer.tsx
+++ b/optuna_dashboard/ts/components/ModelViewer.tsx
@@ -1,5 +1,5 @@
 import * as THREE from "three"
-import React, { useState } from "react"
+import React, { useEffect, useState } from "react"
 import { Canvas } from "@react-three/fiber"
 import { GizmoHelper, GizmoViewport, OrbitControls } from "@react-three/drei"
 import { STLLoader } from "three/examples/jsm/loaders/STLLoader"
@@ -25,51 +25,55 @@ function CustomGizmoHelper(): JSX.Element {
   )
 }
 
+const calculateBoundingBox = (geometries: THREE.BufferGeometry[]) => {
+  const boundingBox = new THREE.Box3()
+  geometries.forEach((geometry) => {
+    const mesh = new THREE.Mesh(geometry)
+    boundingBox.expandByObject(mesh)
+  })
+  return boundingBox
+}
+
 export function ModelViewer(props: ModelViewerProps): JSX.Element {
   const [geometry, setGeometry] = useState<THREE.BufferGeometry[]>([])
-  const [modelSize, setModelSize] = useState<THREE.Vector3>()
+  const [modelSize, setModelSize] = useState<THREE.Vector3>(
+    new THREE.Vector3(10, 10, 10)
+  )
 
-  React.useEffect(() => {
+  function handleLoadedGeometries(geometries: THREE.BufferGeometry[]) {
+    setGeometry(geometries)
+    const boundingBox = calculateBoundingBox(geometries)
+    if (boundingBox !== null) {
+      const size = boundingBox.getSize(new THREE.Vector3())
+      setModelSize(size)
+    }
+  }
+
+  useEffect(() => {
     if ("stl" === props.filetype) {
       const stlLoader = new STLLoader()
-      stlLoader.load(props.src, (stlMesh: THREE.BufferGeometry) => {
-        if (stlMesh) {
-          setGeometry([stlMesh])
-          stlMesh.computeBoundingBox()
-          if (stlMesh.boundingBox === null) {
-            setModelSize(new THREE.Vector3(10, 10, 10))
-          } else {
-            const size = stlMesh.boundingBox.getSize(new THREE.Vector3())
-            setModelSize(size)
-          }
+      stlLoader.load(props.src, (stlGeometries: THREE.BufferGeometry) => {
+        if (stlGeometries) {
+          handleLoadedGeometries([stlGeometries])
         }
       })
     } else if ("3dm" === props.filetype) {
       const loader = new Rhino3dmLoader()
       loader.setLibraryPath("https://cdn.jsdelivr.net/npm/rhino3dm@7.15.0/")
       loader.load(props.src, (object: THREE.Object3D) => {
-        object.traverse(function (child) {
-          // rotate to y-up
-          child.rotateX(-Math.PI / 4)
-        })
         const meshes = object.children as THREE.Mesh[]
-        const rhinoMeshes = meshes.map((mesh) => mesh.geometry)
-        if (rhinoMeshes.length > 0) {
-          setGeometry(rhinoMeshes)
-          rhinoMeshes[0].computeBoundingBox()
-          if (rhinoMeshes[0].boundingBox === null) {
-            setModelSize(new THREE.Vector3(10, 10, 10))
-          } else {
-            const size = rhinoMeshes[0].boundingBox.getSize(new THREE.Vector3())
-            setModelSize(size)
-          }
+        const rhinoGeometries = meshes.map((mesh) => mesh.geometry)
+        if (rhinoGeometries.length > 0) {
+          rhinoGeometries.forEach((rGeometry) => {
+            rGeometry.rotateX(-Math.PI / 4)
+          })
+          handleLoadedGeometries(rhinoGeometries)
         }
       })
     }
   }, [])
-  const cameraPosition = modelSize
-    ? [modelSize.x * 1.5, modelSize.y * 1.5, modelSize.z * 1.5]
-    : [10, 10, 10]
+  const maxModelSize = Math.max(modelSize.x, modelSize.y, modelSize.z)
+  const cameraPosition = [maxModelSize * 2, maxModelSize * 2, maxModelSize * 2]
   const cameraSettings: PerspectiveCamera = {
     fov: modelSize
       ? Math.min(45, Math.atan(modelSize.y / modelSize.z) * (180 / Math.PI) * 2)
@@ -87,9 +91,7 @@ export function ModelViewer(props: ModelViewerProps): JSX.Element {
     >
       <ambientLight />
       <OrbitControls />
-      <gridHelper
-        args={modelSize && [Math.max(modelSize?.x, modelSize?.y) * 5]}
-      />
+      <gridHelper args={[Math.max(modelSize?.x, modelSize?.y) * 5]} />
       {props.hasGizmo && <CustomGizmoHelper />}
       <axesHelper />
       {geometry.length > 0 &&