Unfortunately Arcane Mapper was released with compatibility issues with some AMD drivers. I am happy to say that these issues have been fixed and lighting now works correctly on both AMD and NVidia GPUs. This was due to the cooperation of a few customers who were willing to report the issue, test new versions and report errors.
During the process the lighting was improved to fix a precision issue that could cause "stair step" artifacts on some walls. The result, though, is that the torches and example maps had to be tweaked. If you have a version prior to the fix - Version 1.0.2660 - then you will probably want to get the new assets, otherwise the torches may be harder to place and examples may look a little off. The new assets also include a few carpet objects to help decorate your maps.
Floor and wall decorations, like carpets, should be placed on the "Envronment Details" layer - in this layer they directly use the environment lighting - blending better with the environment. In addition, they do not get in the way when manipulating normal props (on the Props layer).
Note - if you purchased Arcane Mapper recently and have Version 1.0.2660 or later then you will have the improved assets and maps already. Otherwise to get the improved assets, go to the Steam Workshop tab on the Community Hub and Subscribe to the "Environment Example Update" item. That should download the item in your Steam client. Once you have downloaded the package, in Arcane Mapper you can select the Import From Steam in the Steam menu. Then click on the item in the list to import it. See the documentation for more information on importing and exporting packages and Steam Workshop.
The new Environments map should look like this:
Some people are still encountering stability issues, so that is still the top priority. Once that is done the missing features and other improvements will be continued in earnest. Thanks again to everyone who was willing to purchase this product in Early Access and to all those following the product and waiting for release.