The original "gospel" on forest regions was they were processed as a single object, and no matter how many trees/bushes/weeds were in the object, it would be easy on framerates. We've since found that to be false, extremely dense forest regions and/or extremely large forest regions seriously tank the framerates.
A forest region is divided into squares, the size of the squares depends on the width of the object defined in the forests.dat file. Example;Forest ( "Bush01" "Bush01.ace" 3.50f 2.5f 0.9f 1.1f )Those numbers, in meters: width, height, multiplier smallest, multiplier largest. If the width is 3.50f, each square is 3.85 meters wide (last number, 1.1, multiplier times 3.50 meters), and each alternate square has the potential to contain a tree. It might or might not contain a tree, that depends on the density setting, but in a checkerboard pattern every other square will be blank. Therefore only half the squares will be filled. With extremely wide objects, the spaces between will become more apparent, since the size of the blank squares are also defined by the object width. Very small objects:Forest ( "weedsml1" "weedsml1.ace" 1.50f 3.5f 0.9f 1.1f )Will pack in more densely, since the spaces between are smaller.
Typing 999,999,999 in the density won't give you a billion trees or bushes per square mile, what it does it automatically resets to the maximum possible density given the width of the object. With very small objects like weeds, you can create a carpet.
The obvious problem, shown in the lower right corner, is 12FPS on a P4 2.66ghz with a gig of RAM and a Radeon 9700.Big problem there, if you use sparsely populated weed forest regions you might as well not bother, if you pack them in densely it tanks the framerates. So I started experimenting with larger weeds. You can't really make them too much wider without also making them higher, since the cross shape of the forest region object becomes too obvious with low, wide objects. So I came up with:Forest ( "weeds3" "weeds3.ace" 16.0f 8.0f 0.9f 1.1f )And here's what that looks like with a density of 1111:
Not as good, but note the framerates; MUCH better at 29FPS even with AI traffic moving thru.I used some of Phil Voxland's backdrop tree objects in some areas, but the other thing I did was to restrict the density of each forest region to a max of 3333, with most regions being 1111 and an occasional 2222. I also stretched the forest region out along the track in one dimension only - I left the second dimension at the default width.
Here's PO&N6, most forest regions were given max density AND stretched out away from the tracks.
Same area in PO&N7 (probably ready in about two more weeks ), larger tree sizes, less densely populated, and the length stretched as needed, the width left at the default.After experimenting with that for a while, I found the billboard backdrop trees weren't even really essential. Sparsely populated narrow forest regions alongside the tracks leave a lot of bare terrain;
But I had completely forgotten the old model railroader's illusion:
The eye is naturally drawn to the closer objects. Even with the large gap in the trees, you can SEE the bare terrain beyond them, but from the normal viewing angle you don't really LOOK at bare terrain, since the eye is so strongly attracted to the trees.
Cover the bottom of the screen with your hand, then take your hand away. The barren hills stand out only when the foreground trees are hidden.IT'S OUT OF SCALE!!!I used some of the default tree sizes where I was looking for a scrub terrain look, and added some extremely oversized trees.Forest ( "spitpine1sml" "spitpine1.ace" 10.0f 18.0f 0.7f 1.1f )That's the small Judd Spittler fir tree, 18 meters high, minimum 0.7 (18x0.7=12.6meters), maximum 1.1 (18x1.1=19.8meters). Probably realistic proportions, but it looks too small, so;Forest ( "spitpine1" "spitpine1.ace" 12.0f 22.0f 0.4f 2.1f )22 meters isn't a lot larger, but the scaling factor is crazy - 22x2.1=46.2meters, a tree 140 feet high? Yeah, it's out of scale, but the important thing is it LOOKS right. Don't be afraid to experiment with wierder values, you never know what you might come up with.Bottom line, larger tree objects, even out of scale, maximum density of 1111 to 2222, and leave the width alongside the track at the default. Don't worry about filling in everything, the gaps really aren't noticeable.
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