From 7c62bb0908db6bf324d2d92877d275f7c9e6306b Mon Sep 17 00:00:00 2001
From: Lilia_Chen <chenalenavenger@gmail.com>
Date: Tue, 22 Jul 2025 05:27:27 +0100
Subject: [PATCH] feat(stage-ui): VRM model setting: camera psotion (view
 scale) (#309)

---
 packages/i18n/src/locales/en/settings.yaml    |  1 +
 .../i18n/src/locales/zh-Hans/settings.yaml    |  1 +
 .../Scenarios/Settings/ModelSettings/VRM.vue  | 69 +++++++------------
 .../stage-ui/src/components/Scenes/VRM.vue    | 37 +++++++++-
 .../src/components/Scenes/VRM/Model.vue       | 16 ++---
 .../components/Scenes/VRM/OrbitControls.vue   | 11 +++
 packages/stage-ui/src/stores/vrm.ts           |  2 +
 7 files changed, 83 insertions(+), 54 deletions(-)

diff --git a/packages/i18n/src/locales/en/settings.yaml b/packages/i18n/src/locales/en/settings.yaml
index c792f3240..97338f3a1 100644
--- a/packages/i18n/src/locales/en/settings.yaml
+++ b/packages/i18n/src/locales/en/settings.yaml
@@ -566,6 +566,7 @@ vrm:
     z: Z Offset
     fov: FOV (degree)
     rotation-y: Rotation (Y-axis)
+    camera-distance: Camera distance
   switch-to-vrm:
     title: Switch to Live2D Avatar?
     change-to-vrm: Click here to switch to the Live2D avatar setting
diff --git a/packages/i18n/src/locales/zh-Hans/settings.yaml b/packages/i18n/src/locales/zh-Hans/settings.yaml
index c08b53358..a67c5c3ae 100644
--- a/packages/i18n/src/locales/zh-Hans/settings.yaml
+++ b/packages/i18n/src/locales/zh-Hans/settings.yaml
@@ -542,6 +542,7 @@ vrm:
     z: Z轴偏移
     fov: 视角调整（度）
     rotation-y: 模型朝向（Y轴旋转）
+    camera-distance: 相机距离（画面缩放）
   switch-to-vrm:
     title: 想切换至Live2D虚拟形象？
     change-to-vrm: 切换至Live2D虚拟形象设定页面
diff --git a/packages/stage-ui/src/components/Scenarios/Settings/ModelSettings/VRM.vue b/packages/stage-ui/src/components/Scenarios/Settings/ModelSettings/VRM.vue
index 2b63670bb..b898c410e 100644
--- a/packages/stage-ui/src/components/Scenarios/Settings/ModelSettings/VRM.vue
+++ b/packages/stage-ui/src/components/Scenarios/Settings/ModelSettings/VRM.vue
@@ -36,6 +36,7 @@ const {
   cameraFOV,
   selectedModel,
   modelRotationY,
+  cameraDistance,
 } = storeToRefs(vrm)
 const localModelUrl = ref(modelUrl.value)
 
@@ -66,6 +67,12 @@ function urlUploadClick() {
   loadingModel.value = true
   localModelUrl.value = selectedModel.value
 }
+
+function resetCameraDistance() {
+  // Calculate the camera distance that can fit the up-2/3 part of the model in the view
+  const radians = (cameraFOV.value / 2 * Math.PI) / 180
+  cameraDistance.value = (modelSize.value.y / 3) / Math.tan(radians)
+}
 </script>
 
 <template>
@@ -127,51 +134,6 @@ function urlUploadClick() {
       {{ t('settings.vrm.theme-color-from-model.button-extract.title') }}
     </Button>
   </Section>
-  <Section
-    :title="t('settings.vrm.change-model.title')"
-    icon="i-solar:magic-stick-3-bold-duotone"
-    inner-class="text-sm"
-    :class="[
-      'rounded-xl',
-      'bg-white/80  dark:bg-black/75',
-      'backdrop-blur-lg',
-    ]"
-  >
-    <Button
-      variant="secondary" @click=" () => {
-        modelFileDialog.reset()
-        modelFileDialog.open()
-      }"
-    >
-      {{ t('settings.vrm.change-model.from-file') }}...
-    </Button>
-    <div flex items-center gap-2>
-      <Input
-        v-model="localModelUrl"
-        :disabled="loadingModel"
-        class="flex-1"
-        :placeholder="t('settings.vrm.change-model.from-url-placeholder')"
-      />
-      <Button size="sm" variant="secondary" @click="urlUploadClick">
-        {{ t('settings.vrm.change-model.from-url') }}
-      </Button>
-    </div>
-  </Section>
-  <Section
-    :title="t('settings.vrm.theme-color-from-model.title')"
-    icon="i-solar:magic-stick-3-bold-duotone"
-    inner-class="text-sm"
-    :class="[
-      'rounded-xl',
-      'bg-white/80  dark:bg-black/75',
-      'backdrop-blur-lg',
-    ]"
-  >
-    <ColorPalette class="mb-4 mt-2" :colors="palette.map(hex => ({ hex, name: hex }))" mx-auto />
-    <Button variant="secondary" @click="$emit('extractColorsFromModel')">
-      {{ t('settings.vrm.theme-color-from-model.button-extract.title') }}
-    </Button>
-  </Section>
   <Section
     :title="t('settings.vrm.scale-and-position.title')"
     icon="i-solar:scale-bold-duotone"
@@ -281,6 +243,23 @@ function urlUploadClick() {
         </div>
       </template>
     </FieldRange>
+    <FieldRange
+      v-model="cameraDistance"
+      as="div"
+      :min="modelSize.z"
+      :max="modelSize.z * 20"
+      :step="modelSize.z / 100"
+      :label="t('settings.vrm.scale-and-position.camera-distance')"
+    >
+      <template #label>
+        <div flex items-center>
+          <div>{{ t('settings.vrm.scale-and-position.camera-distance') }}</div>
+          <button px-2 text-xs outline-none title="Reset value to default" @click="resetCameraDistance">
+            <div i-solar:forward-linear transform-scale-x--100 text="neutral-500 dark:neutral-400" />
+          </button>
+        </div>
+      </template>
+    </FieldRange>
     <FieldRange
       :model-value="modelRotationY"
       as="div"
diff --git a/packages/stage-ui/src/components/Scenes/VRM.vue b/packages/stage-ui/src/components/Scenes/VRM.vue
index e21b192fc..92c54944e 100644
--- a/packages/stage-ui/src/components/Scenes/VRM.vue
+++ b/packages/stage-ui/src/components/Scenes/VRM.vue
@@ -19,11 +19,13 @@ const {
   selectedModel,
   cameraFOV,
   initialCameraPosition,
+  cameraDistance,
 } = storeToRefs(useVRM())
 
 const modelRef = ref<InstanceType<typeof VRMModel>>()
 
 const camera = shallowRef(new THREE.PerspectiveCamera())
+const controlsRef = ref<InstanceType<typeof OrbitControls>>()
 
 onMounted(() => {
   if (vrmContainerRef.value) {
@@ -64,6 +66,39 @@ watch(selectedModel, () => {
   }
 })
 
+// Bidirectional watch between slider and OrbitControls
+watch(() => controlsRef.value?.getDistance(), (newDistance) => {
+  if (newDistance !== undefined) {
+    // To avoid floating point inaccuracies causing a feedback loop with the other watcher,
+    // we can check if the distance has changed significantly.
+    if (Math.abs(cameraDistance.value - newDistance) > 1e-6) {
+      cameraDistance.value = newDistance
+      initialCameraPosition.value = {
+        x: camera.value.position.x,
+        y: camera.value.position.y,
+        z: camera.value.position.z,
+      }
+    }
+  }
+})
+watch(cameraDistance, (newDistance) => {
+  if (camera.value && controlsRef.value) {
+    const newPosition = new THREE.Vector3()
+    newPosition.copy(camera.value.position.normalize().multiplyScalar(newDistance))
+    camera.value.position.set(
+      newPosition.x,
+      newPosition.y,
+      newPosition.z,
+    )
+    controlsRef.value.update()
+    initialCameraPosition.value = {
+      x: newPosition.x,
+      y: newPosition.y,
+      z: newPosition.z,
+    }
+  }
+})
+
 defineExpose({
   setExpression: (expression: string) => {
     modelRef.value?.setExpression(expression)
@@ -77,6 +112,7 @@ defineExpose({
       <TresAxesHelper :size="1" />
       <TresDirectionalLight :color="0xFFFFFF" :intensity="1.2" :position="[1, 1, 1]" />
       <TresAmbientLight :color="0xFFFFFF" :intensity="1.5" />
+      <OrbitControls ref="controlsRef" />
       <VRMModel
         ref="modelRef"
         :key="selectedModel"
@@ -87,7 +123,6 @@ defineExpose({
         @error="(val) => emit('error', val)"
       />
       <!-- <TresPerspectiveCamera :position="[initialCameraPosition.x, initialCameraPosition.y, initialCameraPosition.z]" :fov="cameraFOV"/> -->
-      <OrbitControls />
     </TresCanvas>
   </div>
 </template>
diff --git a/packages/stage-ui/src/components/Scenes/VRM/Model.vue b/packages/stage-ui/src/components/Scenes/VRM/Model.vue
index 1a8631f95..50e081eb1 100644
--- a/packages/stage-ui/src/components/Scenes/VRM/Model.vue
+++ b/packages/stage-ui/src/components/Scenes/VRM/Model.vue
@@ -161,14 +161,6 @@ watch(modelRotationY, (newRotationY) => {
   }
 })
 
-onUnmounted(() => {
-  disposeBeforeRenderLoop?.()
-  if (vrm.value) {
-    vrm.value.scene.removeFromParent()
-    VRMUtils.deepDispose(vrm.value.scene)
-  }
-})
-
 defineExpose({
   setExpression(expression: string) {
     vrmEmote.value?.setEmotionWithResetAfter(expression, 1000)
@@ -181,6 +173,14 @@ const { pause, resume } = useLoop()
 watch(() => props.paused, (value) => {
   value ? pause() : resume()
 })
+
+onUnmounted(() => {
+  disposeBeforeRenderLoop?.()
+  if (vrm.value) {
+    vrm.value.scene.removeFromParent()
+    VRMUtils.deepDispose(vrm.value.scene)
+  }
+})
 </script>
 
 <template>
diff --git a/packages/stage-ui/src/components/Scenes/VRM/OrbitControls.vue b/packages/stage-ui/src/components/Scenes/VRM/OrbitControls.vue
index b8a23b33d..6e01c8a4a 100644
--- a/packages/stage-ui/src/components/Scenes/VRM/OrbitControls.vue
+++ b/packages/stage-ui/src/components/Scenes/VRM/OrbitControls.vue
@@ -14,6 +14,7 @@ const { camera, renderer } = useTresContext()
 const controls = shallowRef<OrbitControls>()
 const {
   modelSize,
+  cameraDistance,
 } = storeToRefs(useVRM())
 
 // initialize the OrbitControls
@@ -35,11 +36,21 @@ onMounted(() => {
     }
 
     controls.value.enablePan = false
+    // How near and far the camera can zoom
     controls.value.minDistance = modelSize.value.z
+    controls.value.maxDistance = modelSize.value.z * 20
 
     controls.value.update()
+
+    cameraDistance.value = controls.value.getDistance()
   }
 })
+
+defineExpose({
+  controls,
+  getDistance: () => controls.value?.getDistance(),
+  update: () => controls.value?.update(),
+})
 </script>
 
 <template>
diff --git a/packages/stage-ui/src/stores/vrm.ts b/packages/stage-ui/src/stores/vrm.ts
index 6e41452dd..13dc1f50b 100644
--- a/packages/stage-ui/src/stores/vrm.ts
+++ b/packages/stage-ui/src/stores/vrm.ts
@@ -31,6 +31,7 @@ export const useVRM = defineStore('vrm', () => {
 
   const modelObjectUrl = ref<string>()
   const modelRotationY = useLocalStorage('settings/vrm/modelRotationY', 0)
+  const cameraDistance = useLocalStorage('settings/vrm/cameraDistance', 0)
 
   // Manage the object URL lifecycle to prevent memory leaks
   watch(modelFile, (newFile) => {
@@ -70,5 +71,6 @@ export const useVRM = defineStore('vrm', () => {
     cameraFOV,
     initialCameraPosition,
     modelRotationY,
+    cameraDistance,
   }
 })