cocos-creator-template/assets/default_file_content/render-texture/default.rt

{
  "__type__": "cc.RenderTexture",
  "_objFlags": 0,
  "_native": "",
  "content": {
    "base": "2,2,0,0,0,0",
    "w": 256,
    "h": 256,
    "n": ""
  }
}