diff --git a/packages/frontend/src/utility/room/engine.ts b/packages/frontend/src/utility/room/engine.ts
index b976f60217..d565fa0188 100644
--- a/packages/frontend/src/utility/room/engine.ts
+++ b/packages/frontend/src/utility/room/engine.ts
@@ -217,6 +217,7 @@ const TIME_MAP = {
 } as const;
 
 const USE_GLOW = false; // ドローコールが増えて重い
+const ENABLE_SUN_LIGHT = false; // ドローコールが増えて重い
 
 export async function createRoomEngine(roomState: RoomState, canvas: HTMLCanvasElement) {
 	//const babylonEngine = new BABYLON.WebGPUEngine(canvas);
@@ -230,8 +231,8 @@ export class RoomEngine {
 	private canvas: HTMLCanvasElement;
 	private engine: BABYLON.WebGPUEngine;
 	public scene: BABYLON.Scene;
-	private shadowGenerator1: BABYLON.ShadowGenerator;
-	private shadowGenerator2: BABYLON.ShadowGenerator;
+	private shadowGeneratorForRoomLight: BABYLON.ShadowGenerator;
+	private shadowGeneratorForSunLight: BABYLON.ShadowGenerator | null = null;
 	public camera: BABYLON.UniversalCamera;
 	private fixedCamera: BABYLON.UniversalCamera;
 	private birdeyeCamera: BABYLON.ArcRotateCamera;
@@ -382,25 +383,27 @@ export class RoomEngine {
 		this.roomLight.shadowMinZ = 10/*cm*/;
 		this.roomLight.shadowMaxZ = 300/*cm*/;
 
-		this.shadowGenerator1 = new BABYLON.ShadowGenerator(4096, this.roomLight);
-		this.shadowGenerator1.forceBackFacesOnly = true;
-		this.shadowGenerator1.bias = 0.0001;
-		this.shadowGenerator1.usePercentageCloserFiltering = true;
-		this.shadowGenerator1.filteringQuality = BABYLON.ShadowGenerator.QUALITY_HIGH;
+		this.shadowGeneratorForRoomLight = new BABYLON.ShadowGenerator(4096, this.roomLight);
+		this.shadowGeneratorForRoomLight.forceBackFacesOnly = true;
+		this.shadowGeneratorForRoomLight.bias = 0.0001;
+		this.shadowGeneratorForRoomLight.usePercentageCloserFiltering = true;
+		this.shadowGeneratorForRoomLight.filteringQuality = BABYLON.ShadowGenerator.QUALITY_HIGH;
 		//this.shadowGenerator1.useContactHardeningShadow = true;
 
-		const sunLight = new BABYLON.DirectionalLight('sunLight', new BABYLON.Vector3(0.2, -1, -1), this.scene);
-		sunLight.position = new BABYLON.Vector3(-20, 1000, 1000);
-		sunLight.diffuse = this.time === 0 ? new BABYLON.Color3(1.0, 0.9, 0.8) : this.time === 1 ? new BABYLON.Color3(1.0, 0.8, 0.6) : new BABYLON.Color3(0.6, 0.8, 1.0);
-		sunLight.intensity = this.time === 0 ? 2 : this.time === 1 ? 1 : 0.25;
-		sunLight.shadowMinZ = 1000/*cm*/;
-		sunLight.shadowMaxZ = 2000/*cm*/;
+		if (ENABLE_SUN_LIGHT) {
+			const sunLight = new BABYLON.DirectionalLight('sunLight', new BABYLON.Vector3(0.2, -1, -1), this.scene);
+			sunLight.position = new BABYLON.Vector3(-20, 1000, 1000);
+			sunLight.diffuse = this.time === 0 ? new BABYLON.Color3(1.0, 0.9, 0.8) : this.time === 1 ? new BABYLON.Color3(1.0, 0.8, 0.6) : new BABYLON.Color3(0.6, 0.8, 1.0);
+			sunLight.intensity = this.time === 0 ? 2 : this.time === 1 ? 1 : 0.25;
+			sunLight.shadowMinZ = 1000/*cm*/;
+			sunLight.shadowMaxZ = 2000/*cm*/;
 
-		this.shadowGenerator2 = new BABYLON.ShadowGenerator(4096, sunLight);
-		this.shadowGenerator2.forceBackFacesOnly = true;
-		this.shadowGenerator2.bias = 0.0001;
-		this.shadowGenerator2.usePercentageCloserFiltering = true;
-		this.shadowGenerator2.usePoissonSampling = true;
+			this.shadowGeneratorForSunLight = new BABYLON.ShadowGenerator(4096, sunLight);
+			this.shadowGeneratorForSunLight.forceBackFacesOnly = true;
+			this.shadowGeneratorForSunLight.bias = 0.0001;
+			this.shadowGeneratorForSunLight.usePercentageCloserFiltering = true;
+			this.shadowGeneratorForSunLight.usePoissonSampling = true;
+		}
 
 		this.turnOnRoomLight();
 
@@ -497,7 +500,8 @@ export class RoomEngine {
 		this.zGridPreviewPlane.isPickable = false;
 		this.zGridPreviewPlane.isVisible = false;
 
-		this.selectionOutlineLayer = new BABYLON.SelectionOutlineLayer('outliner', this.scene);
+		// 重い。edit modeのときだけ有効にするようにしたい
+		//this.selectionOutlineLayer = new BABYLON.SelectionOutlineLayer('outliner', this.scene);
 
 		watch(this.isEditMode, (v) => {
 			if (v) {
@@ -563,7 +567,7 @@ export class RoomEngine {
 
 	public async init() {
 		await this.loadRoomModel();
-		await this.loadEnvModel();
+		//await this.loadEnvModel();
 		await Promise.all(this.roomState.installedObjects.map(o => this.loadObject({
 			id: o.id,
 			type: o.type,
@@ -841,8 +845,8 @@ export class RoomEngine {
 				m.isPickable = false;
 				m.checkCollisions = false;
 				m.receiveShadows = true;
-				this.shadowGenerator1.addShadowCaster(m);
-				this.shadowGenerator2.addShadowCaster(m);
+				this.shadowGeneratorForRoomLight.addShadowCaster(m);
+				if (this.shadowGeneratorForSunLight != null) this.shadowGeneratorForSunLight.addShadowCaster(m);
 				//if (m.material) (m.material as BABYLON.PBRMaterial).ambientColor = new BABYLON.Color3(1, 1, 1);
 				if (m.material) {
 					(m.material as BABYLON.PBRMaterial).reflectionTexture = this.enableReflectionProbe ? this.reflectionProbe.cubeTexture : this.envMapIndoor;
@@ -934,8 +938,8 @@ export class RoomEngine {
 				} else {
 					if (def.receiveShadows !== false) mesh.receiveShadows = true;
 					if (def.castShadows !== false) {
-						this.shadowGenerator1.addShadowCaster(mesh);
-						this.shadowGenerator2.addShadowCaster(mesh);
+						this.shadowGeneratorForRoomLight.addShadowCaster(mesh);
+						if (this.shadowGeneratorForSunLight != null) this.shadowGeneratorForSunLight.addShadowCaster(mesh);
 					}
 
 					//if (mesh.material) (mesh.material as BABYLON.PBRMaterial).ambientColor = new BABYLON.Color3(0.2, 0.2, 0.2);