Roma Surrectum's trees lag because they are unoptimized, I'm currently optimizing all RS vegetation models to 1/3 to 1/10 of the polycount without sacrificing too much detail. Also I made several new models and made new variations on existing models.
I already send some of my models to dvk.
These models reduce the prevalence of framerate drops (below 30) during to the point that they are almost non-existent when running the game on rather high (not highest) graphics on my main PC which has a 3.2Ghz processor as long as there aren't more then 8000-10000 men on the battlefield. at 8000 men I experience small framerate drops (down to 20 fps) in very dense forests. However the game keeps running very smooth till 10000 men at more open battlefields.
Also I have plans to render 1024x1024 sprites because rtw's automatically generated sprites are of very low quality. This would make far sprite distances obsolete.
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