This has been irking me for a while, but trees just seem to put off too much of a load on maps. I mostly blame the animation they have and when stacked it puts too much of a strain on the map, but I feel this could be corrected by enabling the option to make them still. What im doing now is making the time old dark forest for myself and a few friends to play on so im honestly not too worried about making the map play good , just look good as a dense forest and to be able to move around without staring into the 20 fps horror show. Do any of you know what it is that causes the most lag in forge or how to prevent it? Does Distance fog have any detrimental effects?
I could be wrong on this, but I believe that having lots of overlapping geometry that has masked or translucent materials such as particle FX, glass, shields, and vegetation generally has a pretty high impact on performance. You could try toggling off the procedural ground vegetation and see if that helps.
It does help a little. I found that you can have up to 28 trees in direct sight before Frame Rates drop with or without Decorations toggled. If you have fog enabled it impacts it even more down to about 24 trees in sight. Found a healthy work around by mixing dead trees and rocks, but there is still the issue that so few trees can be used at once and overall performance needs to be addressed I feel.