# Overmap special / mapgen Viewer

**URL:** <https://discourse.cataclysmdda.org/t/overmap-special-mapgen-viewer/29718>\
**Category:** The Lab\
**Created:** [June 10, 2025, 6:23am UTC](https://discourse.cataclysmdda.org/t/overmap-special-mapgen-viewer/29718 "2025-06-10T06:23:04Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Kartoffelbauer1000](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.cataclysmdda.org/kartoffelbauer1000/32/13047_2.png) [@Kartoffelbauer1000](https://discourse.cataclysmdda.org/u/Kartoffelbauer1000)\
**Post date:** [June 10, 2025, 6:23am UTC](https://discourse.cataclysmdda.org/t/overmap-special-mapgen-viewer/29718/1 "2025-06-10T06:23:04Z")

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[In a post a while back](https://discourse.cataclysmdda.org/t/feature-suggestion-for-a-custom-map-editor/29600/9) i asked for some feature suggestions for a potential Map Editor. For the past few months i have been working on this program and am now ready to show what i have implemented so far.

As you probably know, the effort to implement a fully fledged map editor is huge. That is why i have implemented a what is call _Map Viewer_ inspired by [Mapgen Explorer - #21 by \_Fuji](https://discourse.cataclysmdda.org/t/mapgen-explorer/15347/21). This allows you to open up files with Mapgen entries and view the map in a graphical way. When you make changes to the file, the map that is displayed is automatically reloaded with the new changes. With this you can easily create a new map without having to reload the game and see what the map looks like.

_Example with house\_01_

![showcase](https://us1.discourse-cdn.com/flex016/uploads/cataclysmdda/original/2X/1/11655b1126fd3d1e02c4606510481c87fbdab6c3.gif)

This program can be downloaded on [GitHub](https://github.com/Karto1000/CDDA-Map-Editor-v2) under the releases tab.

If you have any suggestions, feedback or bugs you would like to report, feel free to comment on this post or create a new issue in the repository.

I have plans to turn this program into a Map Editor in the future (It is called a _Map Editor_ for a reason). But this felt like the quickest feature to implement to get some feedback and make something that is actually usable.

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**Author:** ![LilShiningMan](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.cataclysmdda.org/lilshiningman/32/8261_2.png) [@LilShiningMan](https://discourse.cataclysmdda.org/u/LilShiningMan)\
**Post date:** [June 10, 2025, 10:54am UTC](https://discourse.cataclysmdda.org/t/overmap-special-mapgen-viewer/29718/2 "2025-06-10T10:54:05Z")

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Looks interesting! Traveling currently, but looking forward to testing this out when I have comp access again

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**Author:** ![LilShiningMan](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.cataclysmdda.org/lilshiningman/32/8261_2.png) [@LilShiningMan](https://discourse.cataclysmdda.org/u/LilShiningMan)\
**Post date:** [June 23, 2025, 4:54am UTC](https://discourse.cataclysmdda.org/t/overmap-special-mapgen-viewer/29718/3 "2025-06-23T04:54:02Z")

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I might be a little dense here, but I’m not getting anything to populate. I’ve chosen the “Open an Existing Map” function and then in the Import Map popup window I choose “Select a mapgen file path” and select a json file and then click the “Import” button at the bottom, but nothing happens.

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**Author:** ![Kartoffelbauer1000](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.cataclysmdda.org/kartoffelbauer1000/32/13047_2.png) [@Kartoffelbauer1000](https://discourse.cataclysmdda.org/u/Kartoffelbauer1000)\
**Post date:** [June 23, 2025, 2:51pm UTC](https://discourse.cataclysmdda.org/t/overmap-special-mapgen-viewer/29718/4 "2025-06-23T14:51:49Z")

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Did you enter the overmap id that the program should look for in the selected file?

For example for the Map `house_01` you would select the file at `data/json/mapgen/house/house01.json` and then enter the overmap terrain id `house_01`

 ![image](https://us1.discourse-cdn.com/flex016/uploads/cataclysmdda/original/2X/1/1c15dd8886f634ca56bdf3e5fc0fb93ab94d7e1c.png)

Is there meaby some error message in the console window which opened when you started the program?

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**Author:** ![LilShiningMan](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.cataclysmdda.org/lilshiningman/32/8261_2.png) [@LilShiningMan](https://discourse.cataclysmdda.org/u/LilShiningMan)\
**Post date:** [June 24, 2025, 4:20am UTC](https://discourse.cataclysmdda.org/t/overmap-special-mapgen-viewer/29718/5 "2025-06-24T04:20:32Z")

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So, I didn’t do that last night but I just tried what you suggested and I’m getting this error

 ![image](https://us1.discourse-cdn.com/flex016/uploads/cataclysmdda/original/2X/6/67b74ba14633a339292c93b61760c5e0d5241e52.png)

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<div class="post-metadata">

**Author:** ![Kartoffelbauer1000](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.cataclysmdda.org/kartoffelbauer1000/32/13047_2.png) [@Kartoffelbauer1000](https://discourse.cataclysmdda.org/u/Kartoffelbauer1000)\
**Post date:** [June 24, 2025, 5:52am UTC](https://discourse.cataclysmdda.org/t/overmap-special-mapgen-viewer/29718/6 "2025-06-24T05:52:19Z")

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When you first launched the application, did you open up the `Welcome to the CDDA Map Editor` tab and select the game directory?

 ![image](https://us1.discourse-cdn.com/flex016/uploads/cataclysmdda/original/2X/1/10a0ea46099a337664d98e75eda02f6ca01727f7.jpeg)

The program has to read the different files to be able to process things like palettes and nested mapgens.