x-plane graphics tweaks

Today I played a bit more with x-plane. I made two flights. One from Baltimore to Newark (with a King Air 350) and one from Philadelphia to Newark (Piper PA 180). Both planes were downloaded from xplane.org. More such goodies can be found there.

Additionally I played a bit with the graphics settings. What I found out was that the compress textures setting is really important. As noted in my previous post, the thing is mostly CPU bound. More objects require more CPU. However, with things like resolution and texture size, video ram is the bottle neck. Since I have a nice 7800 GT, there is 256 MB of memory. This may seem like a lot but there is quite a bit of textures in x-plane. Yesterday I found that it was impossible to set the texture size to extreme since that caused x-plane to reduce visibility to about a mile to keep up the framerate. Reason: I was running out of vram! The solution for that is compression, this is supported by the videocard and a common strategy for working with high resolution textures. Probably this should always be turned on unless the video card is really old.

With texture compression on (in the x-plane render settings), I can now have mega tons of objects, tons of roads (these are actual x-plane settings), extreme texture resolution and about ten AI planes in the air. That looks nice! Hundreds of textures have been included with the x-plane global scenery and they are quite good (compared to e.g. the shit that comes with ms flightsimulator).

With these settings, flying over New York is workable (though framerate suffers a bit). Outside of the cities, the number of objects is much less of a problem. Besides, most cities are quite a bit smaller than NY.

screenshot NY
Another thing I noticed is that the scenery in europe does not appear to include objects. So flying outside of the US is a lot less fun. The Alps though are very detailed. Here the lack of winter textures makes them look unrealistic though. This time of year they should all be snow covered and even in the summer some of them remain snow covered. Not in x-plane. I suppose that is the limitation of the approach taken by the global scenery people (no custom modelling, only take in data from sources like satellite images). However, europe is still 4.7GB of data. Most of this data concerns data coming from various satellite images (high detail). Things like rivers, coastlines, terrain types and elevation are all accurate. So even though Amsterdam does not have objects, it still has the right textures in the right place so you can see where the city ends.

x-plane 8.32

The previous time I posted about x-plane, it was to comment on the then newly released world scenery, which at the time I could only admire via the provided screenshots. Also I was waiting to order a new PC. Well the new PC is in use for a couple of months now and today that 6 dvds I ordered last weekend arrived today. The six dvds cover the world until a little south of Helsinki (too bad) and north of Antartica. When I say cover, I really mean cover. Cover, as in 60 GB of goodness.

It shows. The x-plane world is very detailed. I only tried out a few areas. I took off from Newark to land (well sort off, didn’t make much of an effort to make it a proper landing) at la Guardia a few miles distance. This is a nice route that crosses manhattan and really shows off the flightsimulator and scenery. Basically the upper limit of what you get to see is cpu and memory bound. I have a dual core amd X4400 with 2GB. Plenty of horse power, but not nearly enough for the maximum settings. Clearly this architecture is built for the future (i.e. next decade). Luckily, it all scales down very well. Basically the scenery consists of very detailed terrain and generated objects. The generated objects take into account terrain type; area and expected building height. The settings for the amount you can display range from none, few, default, lots, tons to extreme. It’s tempting to go to extreme.

After all I have a dual core machine with a nice nvidia 7800 GT card. Plenty of horse power for running doom 3 or half life 2 at maximum settings at 1600×1200. However, extreme really is extreme. When flying over new york in real life there are buildings in every direction as far as the eye can see. With the settings set to extreme and visibility to 20 Miles, you literally have tens of thousands of objects in visual range. I doubt PCs exist that can draw that at a reasonable framerate today. And flight simulators require a reasonable framerate of course.

Adding to the problem is the roads setting, which, when set to extreme, draws every road it knows about in visual range. That too is quite a bit of road when flying over NY since it uses actual map data to render roads. So in short, reasonable framerates on my machine mean trading off between viewing distance, number of objects, number of roads, texture resolution (when set to extreme it eats video ram like crazy). Forget about using the maximum setting for any of those except maybe texture resolution. Luckily everything still looks great with the settings moderated a bit.

It’s just really frustrating to be constantly aware of the fact that you are not seeing close to 25% of the data available to you because your bad ass gaming machine just hasn’t got the super computer capability required to do so. It still looks very realistic of course, no complaints about that.

Besides, NY is just a place to take off or land. The beauty of this scenery is that you can fly to say Chicago and have plenty to see on the way. All terrain features are there, mountains, hills, canyons, highways, towns, small villages, rivers, lakes and other things you normally see from the air, all in the right place. Coastlines are extremely detailed (all the NY piers are there). Setting roads and objects to their default settings sort of removes the suggestion of flying over a real city but the rest of the terrain stays as detailed as it is.

When you leave new york in MS flight simulator (which fits easily on a single layer DVD) there’s not much to see. Grey and blue lines suggest where by approximation main roads and rivers should be. The terrain is dull with autogen scenery roughly corresponding to what it thinks the terrain should look like based on the limited data it has. It’s a desert of dullness out there.