Good morning, What is the optimal size for a custom texture for use in 3d max? Would i be ok just using 1024x1024 for my road textures?
Depends on how you set up the material. With a good mult and spec maps you can get away with much much smaller diffuse maps, which is especially great if you want to use multiple diffuse maps as it keeps vram usage down. My next track has 512x2048 diffuse "textures" and I've tried it with a quarter of that (256x1024) and it still looks fine. Point being: Size is not the primary factor for graphical quality.
True , especially when your average speed on track is very often over 100km/h on shorter tracks and close to 200 km/h on bigger tracks. It can make a difference only for screenshots after race.
