diff --git a/src/lights/AmbientLight.js b/src/lights/AmbientLight.js
deleted file mode 100644
index 4f160cc..0000000
--- a/src/lights/AmbientLight.js
+++ /dev/null
@@ -1,12 +0,0 @@
-import { defineComponent } from 'vue';
-import { AmbientLight } from 'three';
-import Light from './Light.js';
-
-export default defineComponent({
-  extends: Light,
-  created() {
-    this.light = new AmbientLight(this.color, this.intensity);
-    this.initLight();
-  },
-  __hmrId: 'AmbientLight',
-});
diff --git a/src/lights/AmbientLight.ts b/src/lights/AmbientLight.ts
new file mode 100644
index 0000000..2697759
--- /dev/null
+++ b/src/lights/AmbientLight.ts
@@ -0,0 +1,11 @@
+import { defineComponent } from 'vue'
+import { AmbientLight } from 'three'
+import Light from './Light'
+
+export default defineComponent({
+  extends: Light,
+  created() {
+    this.initLight(new AmbientLight(this.color, this.intensity))
+  },
+  __hmrId: 'AmbientLight',
+})
diff --git a/src/lights/DirectionalLight.js b/src/lights/DirectionalLight.js
deleted file mode 100644
index a738a56..0000000
--- a/src/lights/DirectionalLight.js
+++ /dev/null
@@ -1,15 +0,0 @@
-import { defineComponent } from 'vue';
-import { DirectionalLight } from 'three';
-import Light from './Light.js';
-
-export default defineComponent({
-  extends: Light,
-  props: {
-    target: Object,
-  },
-  created() {
-    this.light = new DirectionalLight(this.color, this.intensity);
-    this.initLight();
-  },
-  __hmrId: 'DirectionalLight',
-});
diff --git a/src/lights/DirectionalLight.ts b/src/lights/DirectionalLight.ts
new file mode 100644
index 0000000..3f026e6
--- /dev/null
+++ b/src/lights/DirectionalLight.ts
@@ -0,0 +1,14 @@
+import { defineComponent } from 'vue'
+import { DirectionalLight } from 'three'
+import Light from './Light'
+
+export default defineComponent({
+  extends: Light,
+  props: {
+    target: { type: Object, default: () => ({ x: 0, y: 0, z: 0 }) },
+  },
+  created() {
+    this.initLight(new DirectionalLight(this.color, this.intensity))
+  },
+  __hmrId: 'DirectionalLight',
+})
diff --git a/src/lights/HemisphereLight.js b/src/lights/HemisphereLight.js
deleted file mode 100644
index 1a7573a..0000000
--- a/src/lights/HemisphereLight.js
+++ /dev/null
@@ -1,16 +0,0 @@
-import { defineComponent, watch } from 'vue';
-import { HemisphereLight } from 'three';
-import Light from './Light.js';
-
-export default defineComponent({
-  extends: Light,
-  props: {
-    groundColor: { type: String, default: '#444444' },
-  },
-  created() {
-    this.light = new HemisphereLight(this.color, this.groundColor, this.intensity);
-    watch(() => this.groundColor, (value) => { this.light.groundColor.set(value); });
-    this.initLight();
-  },
-  __hmrId: 'HemisphereLight',
-});
diff --git a/src/lights/HemisphereLight.ts b/src/lights/HemisphereLight.ts
new file mode 100644
index 0000000..f17269e
--- /dev/null
+++ b/src/lights/HemisphereLight.ts
@@ -0,0 +1,16 @@
+import { defineComponent, watch } from 'vue'
+import { HemisphereLight } from 'three'
+import Light from './Light'
+
+export default defineComponent({
+  extends: Light,
+  props: {
+    groundColor: { type: String, default: '#444444' },
+  },
+  created() {
+    const light = new HemisphereLight(this.color, this.groundColor, this.intensity)
+    watch(() => this.groundColor, (value) => { light.groundColor.set(value) })
+    this.initLight(light)
+  },
+  __hmrId: 'HemisphereLight',
+})
diff --git a/src/lights/Light.js b/src/lights/Light.js
deleted file mode 100644
index 5f5751d..0000000
--- a/src/lights/Light.js
+++ /dev/null
@@ -1,47 +0,0 @@
-import { defineComponent, watch } from 'vue';
-import Object3D from '../core/Object3D';
-import { bindProp, setFromProp } from '../tools';
-
-export default defineComponent({
-  extends: Object3D,
-  name: 'Light',
-  props: {
-    color: { type: String, default: '#ffffff' },
-    intensity: { type: Number, default: 1 },
-    castShadow: { type: Boolean, default: false },
-    shadowMapSize: { type: Object, default: { x: 512, y: 512 } },
-    shadowCamera: { type: Object, default: {} },
-  },
-  // can't use setup because it will not be used in sub components
-  // setup() {},
-  unmounted() {
-    if (this.light.target) this.removeFromParent(this.light.target);
-  },
-  methods: {
-    initLight() {
-      if (this.light.target) {
-        bindProp(this, 'target', this.light.target, 'position');
-      }
-
-      if (this.light.shadow) {
-        this.light.castShadow = this.castShadow;
-        setFromProp(this.light.shadow.mapSize, this.shadowMapSize);
-        setFromProp(this.light.shadow.camera, this.shadowCamera);
-      }
-
-      ['color', 'intensity', 'castShadow'].forEach(p => {
-        watch(() => this[p], () => {
-          if (p === 'color') {
-            this.light.color.set(this.color);
-          } else {
-            this.light[p] = this[p];
-          }
-        });
-      });
-
-      this.initObject3D(this.light);
-      if (this.light.target) this.addToParent(this.light.target);
-    },
-  },
-  __hmrId: 'Light',
-});
diff --git a/src/lights/Light.ts b/src/lights/Light.ts
new file mode 100644
index 0000000..6227af0
--- /dev/null
+++ b/src/lights/Light.ts
@@ -0,0 +1,59 @@
+import { DirectionalLight, Light, SpotLight } from 'three'
+import { defineComponent, watch } from 'vue'
+import Object3D from '../core/Object3D'
+import { bindProp, setFromProp } from '../tools'
+
+interface LightInterface {
+  light?: Light
+}
+
+type LightWithTarget = SpotLight | DirectionalLight
+
+export default defineComponent({
+  extends: Object3D,
+  name: 'Light',
+  props: {
+    color: { type: String, default: '#ffffff' },
+    intensity: { type: Number, default: 1 },
+    castShadow: { type: Boolean, default: false },
+    shadowMapSize: { type: Object, default: () => ({ x: 512, y: 512 }) },
+    shadowCamera: { type: Object, default: () => ({}) },
+  },
+  setup(): LightInterface {
+    return {}
+  },
+  unmounted() {
+    const light = this.light as LightWithTarget
+    if (light && light.target) this.removeFromParent(light.target)
+  },
+  methods: {
+    initLight(light: Light) {
+      this.light = light
+
+      const lightWithTarget = light as LightWithTarget
+      if (lightWithTarget.target) {
+        bindProp(this, 'target', lightWithTarget.target, 'position')
+      }
+
+      if (this.light?.shadow) {
+        this.light.castShadow = this.castShadow
+        setFromProp(this.light.shadow.mapSize, this.shadowMapSize)
+        setFromProp(this.light.shadow.camera, this.shadowCamera)
+      }
+
+      ['color', 'intensity', 'castShadow'].forEach(p => {
+        watch(() => this[p], () => {
+          if (p === 'color') {
+            light.color.set(this.color)
+          } else {
+            light[p] = this[p]
+          }
+        })
+      })
+
+      this.initObject3D(this.light)
+      if (lightWithTarget.target) this.addToParent(lightWithTarget.target)
+    },
+  },
+  __hmrId: 'Light',
+})
diff --git a/src/lights/PointLight.js b/src/lights/PointLight.js
deleted file mode 100644
index 532f717..0000000
--- a/src/lights/PointLight.js
+++ /dev/null
@@ -1,22 +0,0 @@
-import { defineComponent } from 'vue';
-import { PointLight } from 'three';
-import Light from './Light.js';
-
-export default defineComponent({
-  extends: Light,
-  props: {
-    distance: {
-      type: Number,
-      default: 0,
-    },
-    decay: {
-      type: Number,
-      default: 1,
-    },
-  },
-  created() {
-    this.light = new PointLight(this.color, this.intensity, this.distance, this.decay);
-    this.initLight();
-  },
-  __hmrId: 'PointLight',
-});
diff --git a/src/lights/PointLight.ts b/src/lights/PointLight.ts
new file mode 100644
index 0000000..a79b121
--- /dev/null
+++ b/src/lights/PointLight.ts
@@ -0,0 +1,15 @@
+import { defineComponent } from 'vue'
+import { PointLight } from 'three'
+import Light from './Light'
+
+export default defineComponent({
+  extends: Light,
+  props: {
+    distance: { type: Number, default: 0 },
+    decay: { type: Number, default: 1 },
+  },
+  created() {
+    this.initLight(new PointLight(this.color, this.intensity, this.distance, this.decay))
+  },
+  __hmrId: 'PointLight',
+})
diff --git a/src/lights/RectAreaLight.js b/src/lights/RectAreaLight.js
deleted file mode 100644
index 4a00ab4..0000000
--- a/src/lights/RectAreaLight.js
+++ /dev/null
@@ -1,32 +0,0 @@
-import { defineComponent, watch } from 'vue';
-import { RectAreaLight } from 'three';
-import { RectAreaLightUniformsLib } from 'three/examples/jsm/lights/RectAreaLightUniformsLib.js';
-import { RectAreaLightHelper } from 'three/examples/jsm/helpers/RectAreaLightHelper.js';
-import Light from './Light.js';
-
-export default defineComponent({
-  extends: Light,
-  props: {
-    width: { type: Number, default: 10 },
-    height: { type: Number, default: 10 },
-    helper: Boolean,
-  },
-  created() {
-    RectAreaLightUniformsLib.init();
-    this.light = new RectAreaLight(this.color, this.intensity, this.width, this.height);
-
-    ['width', 'height'].forEach(p => {
-      watch(() => this[p], () => {
-        this.light[p] = this[p];
-      });
-    });
-
-    if (this.helper) {
-      this.lightHelper = new RectAreaLightHelper(this.light);
-      this.light.add(this.lightHelper);
-    }
-
-    this.initLight();
-  },
-  __hmrId: 'RectAreaLight',
-});
diff --git a/src/lights/RectAreaLight.ts b/src/lights/RectAreaLight.ts
new file mode 100644
index 0000000..12dc94e
--- /dev/null
+++ b/src/lights/RectAreaLight.ts
@@ -0,0 +1,33 @@
+import { defineComponent, watch } from 'vue'
+import { RectAreaLight } from 'three'
+import { RectAreaLightUniformsLib } from 'three/examples/jsm/lights/RectAreaLightUniformsLib.js'
+import { RectAreaLightHelper } from 'three/examples/jsm/helpers/RectAreaLightHelper.js'
+import Light from './Light'
+
+export default defineComponent({
+  extends: Light,
+  props: {
+    width: { type: Number, default: 10 },
+    height: { type: Number, default: 10 },
+    helper: Boolean,
+  },
+  created() {
+    RectAreaLightUniformsLib.init()
+    const light = new RectAreaLight(this.color, this.intensity, this.width, this.height)
+
+    const watchProps = ['width', 'height']
+    watchProps.forEach(p => {
+      watch(() => this[p], () => {
+        light[p] = this[p]
+      })
+    })
+
+    if (this.helper) {
+      const lightHelper = new RectAreaLightHelper(light)
+      light.add(lightHelper)
+    }
+
+    this.initLight(light)
+  },
+  __hmrId: 'RectAreaLight',
+})
diff --git a/src/lights/SpotLight.js b/src/lights/SpotLight.js
deleted file mode 100644
index 6013bad..0000000
--- a/src/lights/SpotLight.js
+++ /dev/null
@@ -1,24 +0,0 @@
-import { defineComponent, watch } from 'vue';
-import { SpotLight } from 'three';
-import Light from './Light.js';
-
-export default defineComponent({
-  extends: Light,
-  props: {
-    angle: { type: Number, default: Math.PI / 3 },
-    decay: { type: Number, default: 1 },
-    distance: { type: Number, default: 0 },
-    penumbra: { type: Number, default: 0 },
-    target: Object,
-  },
-  created() {
-    this.light = new SpotLight(this.color, this.intensity, this.distance, this.angle, this.penumbra, this.decay);
-    ['angle', 'decay', 'distance', 'penumbra'].forEach(p => {
-      watch(() => this[p], () => {
-        this.light[p] = this[p];
-      });
-    });
-    this.initLight();
-  },
-  __hmrId: 'SpotLight',
-});
diff --git a/src/lights/SpotLight.ts b/src/lights/SpotLight.ts
new file mode 100644
index 0000000..4a6b959
--- /dev/null
+++ b/src/lights/SpotLight.ts
@@ -0,0 +1,27 @@
+import { defineComponent, watch } from 'vue'
+import { SpotLight } from 'three'
+import Light from './Light'
+
+export default defineComponent({
+  extends: Light,
+  props: {
+    angle: { type: Number, default: Math.PI / 3 },
+    decay: { type: Number, default: 1 },
+    distance: { type: Number, default: 0 },
+    penumbra: { type: Number, default: 0 },
+    target: Object,
+  },
+  created() {
+    const light = new SpotLight(this.color, this.intensity, this.distance, this.angle, this.penumbra, this.decay)
+
+    const watchProps = ['angle', 'decay', 'distance', 'penumbra']
+    watchProps.forEach(p => {
+      watch(() => this[p], () => {
+        light[p] = this[p]
+      })
+    })
+
+    this.initLight(light)
+  },
+  __hmrId: 'SpotLight',
+})
diff --git a/src/lights/index.js b/src/lights/index.js
deleted file mode 100644
index 16e6df9..0000000
--- a/src/lights/index.js
+++ /dev/null
@@ -1,6 +0,0 @@
-export { default as AmbientLight } from './AmbientLight.js';
-export { default as DirectionalLight } from './DirectionalLight.js';
-export { default as HemisphereLight } from './HemisphereLight.js';
-export { default as PointLight } from './PointLight.js';
-export { default as RectAreaLight } from './RectAreaLight.js';
-export { default as SpotLight } from './SpotLight.js';
diff --git a/src/lights/index.ts b/src/lights/index.ts
new file mode 100644
index 0000000..11cc7a1
--- /dev/null
+++ b/src/lights/index.ts
@@ -0,0 +1,6 @@
+export { default as AmbientLight } from './AmbientLight'
+export { default as DirectionalLight } from './DirectionalLight'
+export { default as HemisphereLight } from './HemisphereLight'
+export { default as PointLight } from './PointLight'
+export { default as RectAreaLight } from './RectAreaLight'
+export { default as SpotLight } from './SpotLight'