Help with creating a custom tree object.

[GrudenJ]

Hello everyone,

I'm creating a custom GDL tree object for a detailed Floor Plan view. The tree's 2D symbol uses a semi-transparent fill for a ground shadow effect.

I need the shadow fill to be transparent (e.g., 25% or 50% opacity) so that floor pattern lines, roads, etc., underneath the shadow remain visible. However, when I place two or more of these objects close enough for their shadows to overlap, the overlapping region accumulates the transparency, creating an undesirable, darker shade.

I want the shadow fill to display with a consistent transparency level, even when multiple instances overlap. The overlapping area should not become darker. The visual effect should be as if the shadows merge and display the same single shade of transparency, as shown in the "correct" image below.

Visual Examples:

Single Tree: Shows the desired shadow transparency over the floor (road and lines).

Wrong (Current Behavior): Shows the darker accumulation where the shadows overlap.

Correct (Desired Outcome): Shows the shadows merging with no accumulated darkness.

What GDL techniques or settings can I use to achieve this non-accumulating transparent shadow effect? Is there a way to define a "non-additive" transparent fill in the 2D script?

Thank you for your help!

[runxel]

No, there is no way I am aware of to magically have non-additive transparencies. Only thing you can do is use pen -1 to simulate transparency (as in the factor of foreground to background) without actually having transparency.

But this is rather something for the wishlist. Like a magic pen "-2" maybe? 😄

The only thing you can do is to actually script what you are doing. So, one object and it can have multiple trees and they merge when they are close together.

Sadly objects do not know about what happens around them, so that's why it must come from the same object.

[GrudenJ]

Hm. I expected to not be able to have non-additive transparancies, but i hoped there was a way to script the 2D view, so that they somehow merge automatically. If objects don't know what happenes around them, i guess this isn't really possible. I believe this type of graphical representation of not just trees could help a lot with preparing good looking floor plan presentations... Thank you!