diff --git a/renderer/viewer/lib/mesher/models.ts b/renderer/viewer/lib/mesher/models.ts
index 3658d120..c2075764 100644
--- a/renderer/viewer/lib/mesher/models.ts
+++ b/renderer/viewer/lib/mesher/models.ts
@@ -132,7 +132,7 @@ const getVec = (v: Vec3, dir: Vec3) => {
   return v.plus(dir)
 }
 
-function renderLiquid (world: World, cursor: Vec3, texture: any | undefined, type: number, biome: string, water: boolean, attr: Record<string, any>, isRealWater: boolean) {
+function renderLiquid (world: World, cursor: Vec3, texture: any | undefined, type: number, biome: string, water: boolean, attr: MesherGeometryOutput, isRealWater: boolean) {
   const heights: number[] = []
   for (let z = -1; z <= 1; z++) {
     for (let x = -1; x <= 1; x++) {
@@ -192,13 +192,14 @@ function renderLiquid (world: World, cursor: Vec3, texture: any | undefined, typ
 
     for (const pos of corners) {
       const height = cornerHeights[pos[2] * 2 + pos[0]]
-      attr.t_positions.push(
-        (pos[0] ? 0.999 : 0.001) + (cursor.x & 15) - 8,
-        (pos[1] ? height - 0.001 : 0.001) + (cursor.y & 15) - 8,
-        (pos[2] ? 0.999 : 0.001) + (cursor.z & 15) - 8
+      const OFFSET = 0.0001
+      attr.t_positions!.push(
+        (pos[0] ? 1 - OFFSET : OFFSET) + (cursor.x & 15) - 8,
+        (pos[1] ? height - OFFSET : OFFSET) + (cursor.y & 15) - 8,
+        (pos[2] ? 1 - OFFSET : OFFSET) + (cursor.z & 15) - 8
       )
-      attr.t_normals.push(...dir)
-      attr.t_uvs.push(pos[3] * su + u, pos[4] * sv * (pos[1] ? 1 : height) + v)
+      attr.t_normals!.push(...dir)
+      attr.t_uvs!.push(pos[3] * su + u, pos[4] * sv * (pos[1] ? 1 : height) + v)
 
       let cornerLightResult = baseLight
       if (world.config.smoothLighting) {
@@ -223,7 +224,7 @@ function renderLiquid (world: World, cursor: Vec3, texture: any | undefined, typ
       }
 
       // Apply light value to tint
-      attr.t_colors.push(tint[0] * cornerLightResult, tint[1] * cornerLightResult, tint[2] * cornerLightResult)
+      attr.t_colors!.push(tint[0] * cornerLightResult, tint[1] * cornerLightResult, tint[2] * cornerLightResult)
     }
   }
 }
@@ -487,7 +488,7 @@ const isBlockWaterlogged = (block: Block) => {
 }
 
 let unknownBlockModel: BlockModelPartsResolved
-export function getSectionGeometry (sx, sy, sz, world: World) {
+export function getSectionGeometry (sx: number, sy: number, sz: number, world: World) {
   let delayedRender = [] as Array<() => void>
 
   const attr: MesherGeometryOutput = {
diff --git a/renderer/viewer/lib/worldDataEmitter.ts b/renderer/viewer/lib/worldDataEmitter.ts
index 86f372d1..435d9183 100644
--- a/renderer/viewer/lib/worldDataEmitter.ts
+++ b/renderer/viewer/lib/worldDataEmitter.ts
@@ -197,7 +197,9 @@ export class WorldDataEmitter extends (EventEmitter as new () => TypedEmitter<Wo
   async init (pos: Vec3) {
     this.updateViewDistance(this.viewDistance)
     this.emitter.emit('chunkPosUpdate', { pos })
-    this.emitter.emit('time', bot.time.timeOfDay)
+    if (bot?.time?.timeOfDay) {
+      this.emitter.emit('time', bot.time.timeOfDay)
+    }
     this.emitterGotConnected()
     const [botX, botZ] = chunkPos(pos)
 
diff --git a/src/appViewer.ts b/src/appViewer.ts
index 5ac0beaf..d8149912 100644
--- a/src/appViewer.ts
+++ b/src/appViewer.ts
@@ -1,5 +1,5 @@
 import { WorldDataEmitter, WorldDataEmitterWorker } from 'renderer/viewer/lib/worldDataEmitter'
-import { PlayerStateRenderer } from 'renderer/viewer/lib/basePlayerState'
+import { getInitialPlayerState, PlayerStateRenderer } from 'renderer/viewer/lib/basePlayerState'
 import { subscribeKey } from 'valtio/utils'
 import { defaultWorldRendererConfig, WorldRendererConfig } from 'renderer/viewer/lib/worldrendererCommon'
 import { Vec3 } from 'vec3'
@@ -281,19 +281,31 @@ const initialMenuStart = async () => {
   if (appViewer.currentDisplay === 'world') {
     appViewer.resetBackend(true)
   }
-  appViewer.startPanorama()
+  const demo = new URLSearchParams(window.location.search).get('demo')
+  if (!demo) {
+    appViewer.startPanorama()
+    return
+  }
 
   // const version = '1.18.2'
-  // const version = '1.21.4'
-  // await appViewer.resourcesManager.loadMcData(version)
-  // const world = getSyncWorld(version)
-  // world.setBlockStateId(new Vec3(0, 64, 0), loadedData.blocksByName.water.defaultState)
-  // appViewer.resourcesManager.currentConfig = { version }
-  // await appViewer.resourcesManager.updateAssetsData({})
-  // appViewer.playerState = new BasePlayerState() as any
-  // await appViewer.startWorld(world, 3)
-  // appViewer.backend?.updateCamera(new Vec3(0, 64, 2), 0, 0)
-  // void appViewer.worldView!.init(new Vec3(0, 64, 0))
+  const version = '1.21.4'
+  const { loadMinecraftData } = await import('./connect')
+  const { getSyncWorld } = await import('../renderer/playground/shared')
+  await loadMinecraftData(version)
+  const world = getSyncWorld(version)
+  world.setBlockStateId(new Vec3(0, 64, 0), loadedData.blocksByName.water.defaultState)
+  world.setBlockStateId(new Vec3(1, 64, 0), loadedData.blocksByName.water.defaultState)
+  world.setBlockStateId(new Vec3(1, 64, 1), loadedData.blocksByName.water.defaultState)
+  world.setBlockStateId(new Vec3(0, 64, 1), loadedData.blocksByName.water.defaultState)
+  world.setBlockStateId(new Vec3(-1, 64, -1), loadedData.blocksByName.water.defaultState)
+  world.setBlockStateId(new Vec3(-1, 64, 0), loadedData.blocksByName.water.defaultState)
+  world.setBlockStateId(new Vec3(0, 64, -1), loadedData.blocksByName.water.defaultState)
+  appViewer.resourcesManager.currentConfig = { version }
+  appViewer.playerState.reactive = getInitialPlayerState()
+  await appViewer.resourcesManager.updateAssetsData({})
+  await appViewer.startWorld(world, 3)
+  appViewer.backend!.updateCamera(new Vec3(0, 65.7, 0), 0, -Math.PI / 2) // Y+1 and pitch = PI/2 to look down
+  void appViewer.worldView!.init(new Vec3(0, 64, 0))
 }
 window.initialMenuStart = initialMenuStart
 
diff --git a/src/reactUi.tsx b/src/reactUi.tsx
index 138696b0..8e94b35d 100644
--- a/src/reactUi.tsx
+++ b/src/reactUi.tsx
@@ -276,13 +276,17 @@ const PerComponentErrorBoundary = ({ children }) => {
   </ErrorBoundary>)
 }
 
-renderToDom(<App />, {
-  strictMode: false,
-  selector: '#react-root',
-})
+if (!new URLSearchParams(window.location.search).get('no-ui')) {
+  renderToDom(<App />, {
+    strictMode: false,
+    selector: '#react-root',
+  })
+}
 
 disableReactProfiling()
 function disableReactProfiling () {
+  if (window.reactPerfPatchApplied) return
+  window.reactPerfPatchApplied = true
   //@ts-expect-error
   window.performance.markOrig = window.performance.mark
   //@ts-expect-error