When to use a Walkable Area Mask?
Note that when using IndoorAtlas, the map paths aka “mapped area” automatically softly restricts the area where the blue dot may travel. Softly here refers to the fact that the blue dot can travel through small gaps (roughly 1-2m) in the map coverage, to ease mapping open areas. In some spaces and usage scenarios it may be preferred that the blue dot movement is further restricted, for example:
- To not dwell over shelves in a grocery store or logistics warehouse.
- To not cross through non-walkable area such as shelves or multi-floor openings at all.
When positioning is uncertain of the correct corridor, with using walkable area mask it may dwell on the wrong corridor, whereas without mask it would likely stay in between the corridors. The severity of this downside depends on the use case.
Creating a mask image
In the above situations you can improve performance by adding a mask image.
- Mask image is same size bitmap image as the
- You can create the mask with any image editing software. Use the floor plan image as a basis.
Creating mask with Gimp
- Draw walkable area as black.
- Draw non-walkable area as white.
- Don’t use other colors.
Pay attention to the following when creating a mask image:
- Spaces/area with narrow corridors and tight shelves
- Create large enough openings around doors. E.g. 2m, even if the door is 1m. Otherwise you may see behavior where the blue dot moves too slowly or not at all in to the room.
- Keep all walkable areas (black) at least 1.5m wide. Do this even if the corridor/area is less than 1.5m wide in reality.
- Spaces with wide corridors / lobbies (e.g. malls, airports)
- Mask can be extended slightly on the corridors and lobbies to prevent the blue dot from entering shops and other unmapped area or to dwell over the walls
- Draw area near escalators and stairs walkable on all mapped floors.
- Remember to draw entrances walkable (outdoor-indoor).
Figure 1. Good mask, shelves (white) are think enough. Note that your mapping paths must match with the black areas -- paths on white area are not used! You can check this in app.indooratlas.com.
Figure 2. Bad Mask : too thin walls (white).
Please see the images below on how to upload the image. Once you’ve uploaded the mask image, map generation is automatically started to ensure your next map revision contains the mask.