# Preview Your Scene Once you have [built a new scene](#create-your-first-scene) or downloaded a [scene example](https://studios.decentraland.org/resources?sdk_version=SDK7) you can preview it locally. ## Using the Scene Editor in Creator Hub Make sure you've [installed the Creator Hub](https://github.com/decentraland/docs/blob/main/creator/sdk7/get-started/editor-installation.md). 1. Open your scene project. 2. Click the **Preview** button on the top-right corner. This will open a new window with the Decentraland Desktop Explorer, running just your scene. There you can move around the scene and interact with interactive items. ![](/files/kFXFURDUtsBJrB1sRPNv) Configure different preview options from the dropdown menu next to the **Preview** button: * **Open Console Window During Preview**: Opens a new window with the console output of the scene. This is useful to debug errors in the scene. * **Skip Auth Screen**: Skips the account selection screen and automatically logs you in with your currently logged in account. This is disabled by default, enable it if you want to test multiple accounts. * **Landscape Terrain Enabled**: Toggles the landscape around the scene. This is enabled by default, disable it to lower the scene's memory footprint. * **Show QR Code for Mobile**: Displays a QR code that opens your scene preview in the [Decentraland mobile app](/creator/scenes-sdk7/building-for-mobile/building-for-mobile.md). Scan the code with a phone on the same Wi-Fi network as your computer. See [Preview on mobile](/creator/scenes-sdk7/building-for-mobile/preview-on-mobile.md) for details. {% hint style="info" %} **📱 Preview on mobile**: You can also preview your scene directly on the [Decentraland mobile app](/creator/scenes-sdk7/building-for-mobile/building-for-mobile.md). Use the **Show QR Code for Mobile** option in Creator Hub, or run `npm run start -- --mobile` from the CLI. See [Building for Mobile](/creator/scenes-sdk7/building-for-mobile/building-for-mobile.md) for the full guide. {% endhint %} ## Using the CLI To preview a scene run the following command on the scene's main folder: ```bash npm run start -- --explorer-alpha ``` Any dependencies that are missing are installed and then the CLI opens the scene in a new browser tab automatically. It creates a local web server in your system and points the web browser tab to this local address. Every time you make changes to the scene, the preview reloads and updates automatically, so there's no need to run the command again. {% hint style="warning" %} **📔 Note**: Some scenes depend on communicating with an external server to carry out custom logic or store and retrieve data. When previewing one of these scenes, you'll likely have to also run the server locally on another port. Check the scene's readme for instructions on how to launch the server as well as the scene. {% endhint %} ### Parameters of the preview command You can add the following flags to the `npm run start` command to change its behavior: * `-- --web3` Connects preview to browser wallet to use the associated avatar and account. * `-- --no-debug` Disable the debug panel, that shows scene and performance stats. * `-- --explorer-alpha` Runs the preview in the new Decentraland Desktop client. * `-- --mobile` (alias `-- -m`) Shows a QR code in the terminal that opens your scene in the [Decentraland mobile app](/creator/scenes-sdk7/building-for-mobile/building-for-mobile.md) on a phone connected to the same Wi-Fi network. See [Preview on mobile](/creator/scenes-sdk7/building-for-mobile/preview-on-mobile.md). * `-- --skip-version-checks` Avoids checking if the scene's SDK framework version matches your CLI version, and launches the preview anyway. * `-- --port` to assign a specific port to run the scene. Otherwise it will use whatever port is available. * `-- --no-browser` to prevent the preview from opening a new browser tab. * `-- --w` or `-- --no-watch` to not open watch for filesystem changes and avoid hot-reload whenever the scene's code changes. * `-- --c` or `-- --ci` To run the parcel previewer on a remote unix server {% hint style="warning" %} **📔 Note**: Parameters need to be added with two series of dashes, for example `npm run start -- --web3`. {% endhint %} ### Advanced: Fast iteration with remote asset bundles For heavy scenes with many 3D models, you can speed up scene loading and reloading by reusing the [asset bundles](/creator/scenes-sdk7/optimizing/performance-optimization.md#asset-bundle-conversion) that are already published on Decentraland's servers, instead of loading the raw unoptimized 3D models. This is especially useful when iterating on code-only changes. To enable this mode, launch the Decentraland Desktop client with the following arguments: ```bash npm run start -- --realm http://127.0.0.1:8000/ --position 0,0 --local-scene true --debug --skip-version-check true --lsd-use-remote-ab ``` The `` argument changes depending on where the scene is already published: * **In Genesis City**: `--lsd-remote-ab-server Genesis` * **In a World**: `--lsd-remote-ab-world .dcl.eth` For example, to preview a local copy of a scene that's already deployed to a World: ```bash npm run start -- --realm http://127.0.0.1:8000/ --position 0,0 --local-scene true --debug --skip-version-check true --lsd-use-remote-ab --lsd-remote-ab-world myworld.dcl.eth ``` In both cases, `--realm http://127.0.0.1:8000/` points the client at your local preview server (run `npm run start` first to start it), and `--local-scene true` tells the client to load the scene's code from there. {% hint style="warning" %} **📔 Important**: When using this mode, it's recommended that **all** of its art are already published, with their asset bundles fully processed by the content servers. If you've added any new assets, you'll miss out on the optimized loading as they will be loaded as raw gltf files, as happens when you normally run a preview. But if you locally modified an asset that was already published, maintaining the same file name, then you'll be seeing the old published version of that asset. In that case, redeploy the scene first, wait for the asset bundles to be generated (see [Asset bundle conversion](/creator/scenes-sdk7/optimizing/performance-optimization.md#asset-bundle-conversion)), and then resume using this mode for code-only iteration. {% endhint %} ## Upload a scene to decentraland Once you're happy with your scene, you can upload it and publish it to Decentraland. For this you must own LAND, a Decentraland NAME, or an ETH ENS name, or have permissions given by someone that does. See [publishing](/creator/scenes-sdk7/publishing/publishing.md) for instructions on how to do that. ## Preview scene size The scene size shown in the preview is based on the scene's configuration. Edit this on the second tab of the scene menu in the Scene Editor. ![](/files/VvOOvNR29BEczrlXjudC) Use the dropdowns and click **Apply Layout** to change the dimensions of your scene. You can also click each individual parcel to toggle it off from your layout. ![](/files/13jWKPxFM1X7Ats3rYgH) You can also edit the *scene.json* file to list multiple parcels in the "parcels" field. See [set parcels via the command line](/creator/scenes-sdk7/kinds-of-projects/scene-metadata.md#scene-parcels) for more details. {% hint style="info" %} **💡 Tip**: While running the preview, the parcel coordinates don't need to match those that your scene will really use, as long as they're adjacent and are arranged into the same shape. You will have to replace these with the actual coordinates later when you [deploy the scene](#upload-a-scene-to-decentraland). {% endhint %} ## View the scene console Open the console by clicking the ![](/files/U3NUJd1Ri2m0ihUjwtiJ) icon on the top-right corner. Here you can see any error messages, and also any text that your scene prints to the console via `console.log()`. You can also open it by pressing the **\`** key on your keyboard. You can also press Shift + **\`** to open the console even wider, in case you need to view more text. ## Test a multiplayer scene locally If you launch a scene preview and open it in two (or more) different explorer windows, each open window will be interpreted as a separate player, and a mock communications server will keep these players in sync. Interact with the scene on one window, then switch to the other to see that the effects of that interaction are also visible there. Using the Creator Hub, click the Preview button a second time, and that opens a second Decentraland explorer window. You must connect on both windows with different addresses. The same sessions will remain open as the scene reloads. ![](/files/kFXFURDUtsBJrB1sRPNv) As an alternative, you can open a second Decentraland explorer window by writing the following into a browser URL: > `decentraland://realm=http://127.0.0.1:8000&local-scene=true&debug=true&multi-instance=true` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.decentraland.org/creator/scenes-sdk7/getting-started/preview-scene.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.