diff --git a/viewer/lib/atlas.js b/viewer/lib/atlas.js
index 7f45f03c..d36ccca3 100644
--- a/viewer/lib/atlas.js
+++ b/viewer/lib/atlas.js
@@ -13,9 +13,18 @@ function nextPowerOfTwo (n) {
   return n + 1
 }
 
+function readTexture (basePath, name) {
+  if (name === 'missing_texture.png') {
+    // grab ./missing_texture.png
+    basePath = __dirname
+  }
+  return fs.readFileSync(path.join(basePath, name), 'base64')
+}
+
 function makeTextureAtlas (mcAssets) {
   const blocksTexturePath = path.join(mcAssets.directory, '/blocks')
   const textureFiles = fs.readdirSync(blocksTexturePath).filter(file => file.endsWith('.png'))
+  textureFiles.unshift('missing_texture.png')
 
   const texSize = nextPowerOfTwo(Math.ceil(Math.sqrt(textureFiles.length)))
   const tileSize = 16
@@ -35,7 +44,7 @@ function makeTextureAtlas (mcAssets) {
     texturesIndex[name] = { u: x / imgSize, v: y / imgSize, su: tileSize / imgSize, sv: tileSize / imgSize }
 
     const img = new Image()
-    img.src = 'data:image/png;base64,' + fs.readFileSync(path.join(blocksTexturePath, textureFiles[i]), 'base64')
+    img.src = 'data:image/png;base64,' + readTexture(blocksTexturePath, textureFiles[i])
     g.drawImage(img, 0, 0, 16, 16, x, y, 16, 16)
   }
 
diff --git a/viewer/lib/missing_texture.png b/viewer/lib/missing_texture.png
new file mode 100644
index 00000000..affd9d68
Binary files /dev/null and b/viewer/lib/missing_texture.png differ
diff --git a/viewer/lib/models.js b/viewer/lib/models.js
index 5ae9535b..9f8938ec 100644
--- a/viewer/lib/models.js
+++ b/viewer/lib/models.js
@@ -264,8 +264,8 @@ function renderElement (world, cursor, element, doAO, attr, globalMatrix, global
         if (block.name === 'redstone_wire') {
           tint = tints.redstone[`${block.getProperties().power}`]
         } else if (block.name === 'birch_leaves' ||
-                   block.name === 'spruce_leaves' ||
-                   block.name === 'lily_pad') {
+          block.name === 'spruce_leaves' ||
+          block.name === 'lily_pad') {
           tint = tints.constant[block.name]
         } else if (block.name.includes('leaves') || block.name === 'vine') {
           tint = tints.foliage[biome]
@@ -478,7 +478,9 @@ function matchProperties (block, properties) {
 }
 
 function getModelVariants (block, blockStates) {
-  const state = blockStates[block.name]
+  // air, cave_air, void_air and so on...
+  if (block.name.includes('air')) return []
+  const state = blockStates[block.name] ?? blockStates.missing_texture
   if (!state) return []
   if (state.variants) {
     for (const [properties, variant] of Object.entries(state.variants)) {
diff --git a/viewer/lib/modelsBuilder.js b/viewer/lib/modelsBuilder.js
index ecd1bc35..1a6ab5cb 100644
--- a/viewer/lib/modelsBuilder.js
+++ b/viewer/lib/modelsBuilder.js
@@ -34,6 +34,7 @@ function getModel (name, blocksModels) {
 }
 
 function prepareModel (model, texturesJson) {
+  // resolve texture names eg west: #all -> blocks/stone
   for (const tex in model.textures) {
     let root = model.textures[tex]
     while (root.charAt(0) === '#') {
@@ -94,6 +95,19 @@ function resolveModel (name, blocksModels, texturesJson) {
 
 function prepareBlocksStates (mcAssets, atlas) {
   const blocksStates = mcAssets.blocksStates
+  mcAssets.blocksStates.missing_texture = {
+    variants: {
+      normal: {
+        model: 'missing_texture'
+      }
+    }
+  }
+  mcAssets.blocksModels.missing_texture = {
+    parent: 'block/cube_all',
+    textures: {
+      all: 'blocks/missing_texture'
+    }
+  }
   for (const block of Object.values(blocksStates)) {
     if (!block) continue
     if (block.variants) {
diff --git a/viewer/lib/utils.js b/viewer/lib/utils.js
index e91ff69f..382c0573 100644
--- a/viewer/lib/utils.js
+++ b/viewer/lib/utils.js
@@ -10,7 +10,12 @@ const THREE = require('three')
 const path = require('path')
 
 const textureCache = {}
+// todo not ideal, export different functions for browser and node
 function loadTexture (texture, cb) {
+  if (process.platform === 'browser') {
+    return require('./utils.web').loadTexture(texture, cb)
+  }
+
   if (textureCache[texture]) {
     cb(textureCache[texture])
   } else {
@@ -22,6 +27,9 @@ function loadTexture (texture, cb) {
 }
 
 function loadJSON (json, cb) {
+  if (process.platform === 'browser') {
+    return require('./utils.web').loadJSON(json, cb)
+  }
   cb(require(path.resolve(__dirname, '../../public/' + json)))
 }
 
diff --git a/viewer/lib/viewer.js b/viewer/lib/viewer.js
index 14d64a45..db02d904 100644
--- a/viewer/lib/viewer.js
+++ b/viewer/lib/viewer.js
@@ -27,6 +27,14 @@ class Viewer {
     this.primitives = new Primitives(this.scene, this.camera)
 
     this.domElement = renderer.domElement
+    this.playerHeight = 1.6
+    this.isSneaking = false
+  }
+
+  resetAll () {
+    this.world.resetWorld()
+    this.entities.clear()
+    this.primitives.clear()
   }
 
   setVersion (version) {
@@ -66,7 +74,11 @@ class Viewer {
   }
 
   setFirstPersonCamera (pos, yaw, pitch) {
-    if (pos) new TWEEN.Tween(this.camera.position).to({ x: pos.x, y: pos.y + 1.6, z: pos.z }, 50).start()
+    if (pos) {
+      let y = pos.y + this.playerHeight
+      if (this.isSneaking) y -= 0.3
+      new TWEEN.Tween(this.camera.position).to({ x: pos.x, y, z: pos.z }, 50).start()
+    }
     this.camera.rotation.set(pitch, yaw, 0, 'ZYX')
   }
 
diff --git a/viewer/lib/worker.js b/viewer/lib/worker.js
index ad76d37e..b7431677 100644
--- a/viewer/lib/worker.js
+++ b/viewer/lib/worker.js
@@ -54,6 +54,9 @@ self.onmessage = ({ data }) => {
   } else if (data.type === 'blockUpdate') {
     const loc = new Vec3(data.pos.x, data.pos.y, data.pos.z).floored()
     world.setBlockStateId(loc, data.stateId)
+  } else if (data.type === 'reset') {
+    world = null
+    blocksStates = null
   }
 }
 
diff --git a/viewer/lib/worldView.js b/viewer/lib/worldView.js
index ad0ffa44..ec2ccd98 100644
--- a/viewer/lib/worldView.js
+++ b/viewer/lib/worldView.js
@@ -102,10 +102,10 @@ class WorldView extends EventEmitter {
     delete this.loadedChunks[`${pos.x},${pos.z}`]
   }
 
-  async updatePosition (pos) {
+  async updatePosition (pos, force = false) {
     const [lastX, lastZ] = chunkPos(this.lastPos)
     const [botX, botZ] = chunkPos(pos)
-    if (lastX !== botX || lastZ !== botZ) {
+    if (lastX !== botX || lastZ !== botZ || force) {
       const newView = new ViewRect(botX, botZ, this.viewDistance)
       for (const coords of Object.keys(this.loadedChunks)) {
         const x = parseInt(coords.split(',')[0])
diff --git a/viewer/lib/worldrenderer.js b/viewer/lib/worldrenderer.js
index b464401d..744224a7 100644
--- a/viewer/lib/worldrenderer.js
+++ b/viewer/lib/worldrenderer.js
@@ -12,10 +12,14 @@ function mod (x, n) {
 class WorldRenderer {
   constructor (scene, numWorkers = 4) {
     this.sectionMeshs = {}
+    this.active = false
+    this.version = undefined
     this.scene = scene
     this.loadedChunks = {}
     this.sectionsOutstanding = new Set()
     this.renderUpdateEmitter = new EventEmitter()
+    this.blockStatesData = undefined
+    this.texturesDataUrl = undefined
 
     this.material = new THREE.MeshLambertMaterial({ vertexColors: true, transparent: true, alphaTest: 0.1 })
 
@@ -60,23 +64,43 @@ class WorldRenderer {
     }
   }
 
-  setVersion (version) {
+  resetWorld () {
+    this.active = false
     for (const mesh of Object.values(this.sectionMeshs)) {
       this.scene.remove(mesh)
     }
     this.sectionMeshs = {}
+    for (const worker of this.workers) {
+      worker.postMessage({ type: 'reset' })
+    }
+  }
+
+  setVersion (version) {
+    this.version = version
+    this.resetWorld()
+    this.active = true
     for (const worker of this.workers) {
       worker.postMessage({ type: 'version', version })
     }
 
-    loadTexture(`textures/${version}.png`, texture => {
+    this.updateTexturesData()
+  }
+
+  updateTexturesData () {
+    loadTexture(this.texturesDataUrl || `textures/${this.version}.png`, texture => {
       texture.magFilter = THREE.NearestFilter
       texture.minFilter = THREE.NearestFilter
       texture.flipY = false
       this.material.map = texture
     })
 
-    loadJSON(`blocksStates/${version}.json`, blockStates => {
+    const loadBlockStates = () => {
+      return new Promise(resolve => {
+        if (this.blockStatesData) return resolve(this.blockStatesData)
+        return loadJSON(`blocksStates/${this.version}.json`, resolve)
+      })
+    }
+    loadBlockStates().then((blockStates) => {
       for (const worker of this.workers) {
         worker.postMessage({ type: 'blockStates', json: blockStates })
       }
diff --git a/viewer/prerender.js b/viewer/prerender.js
index be0c25f7..8f525adb 100644
--- a/viewer/prerender.js
+++ b/viewer/prerender.js
@@ -5,14 +5,14 @@ const mcAssets = require('minecraft-assets')
 const fs = require('fs-extra')
 
 const texturesPath = path.resolve(__dirname, '../public/textures')
-if (!fs.existsSync(texturesPath)) {
-  fs.mkdirSync(texturesPath)
+if (fs.existsSync(texturesPath) && !process.argv.includes('-f')) {
+  console.log('textures folder already exists, skipping...')
+  process.exit(0)
 }
+fs.mkdirSync(texturesPath, { recursive: true })
 
 const blockStatesPath = path.resolve(__dirname, '../public/blocksStates')
-if (!fs.existsSync(blockStatesPath)) {
-  fs.mkdirSync(blockStatesPath)
-}
+fs.mkdirSync(blockStatesPath, { recursive: true })
 
 const supportedVersions = require('./lib/version').supportedVersions