[discussion] add brief camera story

mathbox-react/src/stories/Camera.stories.tsx

@@ -0,0 +1,59 @@
+import React from "react"
+import { Story, Meta } from "@storybook/react"
+import { OrbitControls } from "three/examples/jsm/controls/OrbitControls"
+
+import { Camera, Cartesian, Surface, Area, Grid } from "../components/components"
+import { ContainedMathbox } from "../index"
+
+export default {
+  title: "Camera",
+  component: Camera,
+  argTypes: {},
+} as Meta<typeof Camera>
+
+const options = {
+  plugins: ["core", "controls", "cursor"],
+  controls: {
+    klass: OrbitControls,
+  },
+}
+
+const Template: Story<React.ComponentProps<typeof Surface>> = (args) => (
+  <ContainedMathbox options={options} containerStyle={{ height: 450 }}>
+    <Cartesian
+      range={[
+        [-5, 5],
+        [-2, 2],
+        [-5, 5],
+      ]}
+    >
+      <Camera
+        lookAt={[0, 0, 0]}
+        liveProps={
+          {
+            position: t => [
+              5 * Math.cos(t),
+              2,
+              3 * Math.sin(t),
+            ]
+          }
+        }
+        proxy
+      />
+      <Grid axes="xz" />
+      <Area
+        width={64}
+        height={64}
+        axes={["x", "z"]}
+        expr={(emit, x, z, i, j, t) => {
+          const y = Math.sin(x - t) * Math.cos(z - t)
+          emit(x, y, z)
+        }}
+      />
+      <Surface color='rgb(48,144,255)' shaded />
+    </Cartesian>
+  </ContainedMathbox>
+)
+
+export const DefaultCamera = Template.bind({})
+DefaultCamera.args = {}