ID:1882791
 
(See the best response by Lummox JR.)
Code:
Not really applicable


Problem description:

When I place multiple turfs onto the same tile in the DM map editor, these turfs will kind of get smushed together, with the lower turfs deleted and their appearances added to the topmost turf's underlays.

However, when I set the blend_mode of the top most turf to something, like ICON_ADD... all of the underlays are also drawn in this same blend mode as if there were multiple objects on top of one another with this blend mode.

For my purposes, however, I need these turfs with the underlays to behave as if there is only one object with the blend_mode. As if the turf has no underlays but instead has all of the lower-turfs' icons blended together using ICON_UNDERLAY.

For example:

This image shows the undesired rendering of a weed turf on top of a grass turf. This was created by placing a weed turf on top of a grass turf in the DM map editor. The turf's blend_mode is set to BLEND_MULTIPLY.


This image shows the desired rendering of a weed turf on top of a grass turf. The turf here was created at runtime rather than world initialization, and does not have any underlays. The grass icon was blended with the weed icon using ICON_UNDERLAY. The turf's blend_mode is set to BLEND_MULTIPLY.

I am seeking the desired rendering behavior for maps that are included in the DME and loaded at world initialization, with turfs placed on top of one another in the DM map editor.

I have no idea where to begin to go about achieving this. Any advice?
Best response
You'll want the underlays' blend modes to be BLEND_OVERLAY. BLEND_DEFAULT will defer to the parent atom/overlay for its blend mode.

A quick fix for this is:

turf/blend_mode = BLEND_OVERLAY