L3DT documentation
Large 3D terrain generator

Image drape

If you are editing or designing a map, it may be useful to use the image drape function. This function will overlay an image, semi-transparently, over the main map display. To access this option, select the 'View→Image drape…' menu option. This will open the Image drape settings window, shown below:

Loading a drape image from a file Using a project map as a drape

If you would like to overlay a map in the project (e.g. heightfield, texture, etc.), then enable the Use project map check-box, and select the desired map. If instead you wish to overlay an image from a file, select the Load from file check-box and enter the image filename, or use the browse button ('…'). Allowed image formats include .bmp, .jpg/.jpeg and .png.

Transparency effects

Drape transparency

The drape transparency value determined how 'see through' the the drape overlay will be. The allowed values range from 0 (fully opaque) to 1 (fully transparent).

PNG transparency is not currently supported, but should be in future releases.

Drape transparent colour

You can nominate one RGB colour in the drape image to be transparent using the Drape transparent colour option. If this option is enabled, wherever the drape image has this colour it will be fully transparent, and show the map beneath it.

Map transparent colour

You can also nominate one RGB colour in the map to be transparent using the Map transparent colour option. If this option is enabled, wherever the map has this colour it will be fully obscured by the drape overlay.

Removing the overlay

To remove the overlay, click on the Clear overlay button in the Image drape settings window.


One application of the image drape feature is to help users design maps from topographical images or rough sketches, such as this:

(Note that the overlay image can be in colour, if you like.)

When loaded into L3DT using the default settings, and applied over a blank design map, the above image overlay looks like this:

Now you can start painting using the design map brush. For further discussion on painting design maps, please refer to the designing a fjord tutorial.

Notes and warnings

The image overlay is an application-level setting, so it will be persistent for all maps you have loaded, and any new ones you create.

Users are advised to avoid using image drapes that are larger than 1024×1024 pixels, as this will adversely affect the responsiveness of the user interface.

l3dt/userguide/view/overlay.txt · Last modified: 2017/08/31 06:17 (external edit)
Except where otherwise noted, content on this wiki is licensed under the following license:CC Attribution-Share Alike 3.0 Unported
Recent changes RSS feed Donate Powered by PHP Valid XHTML 1.0 Valid CSS Driven by DokuWiki