I'm interested in creating a flight simulator, and I'm trying to decide what is the best terrain tool for it. There's a lot of impressive-looking ones out there, so I'm trying to research before buying. I feel like I will need very large terrains. Standing on a hill, you can see about 20 miles, from 10,000 feet up, you can see a lot farther. So terrains would necessarily be big. That means framerates would be a concern. Does WorldStreamer sound like a good option? Perhaps the TerrainSticher be handy as well? I feel like with many of these tools, I would need to make many terrains and glue them together, yes? I love seeing tree leaves fluttering and grass waving in the demos I've seen, but for my sim that's not a huge concern. Trees and grasses don't need to be animated, necessarily. I see a lot about "procedural" development, and that's fine, but I would like to place landmarks (rivers, mountains) for at least a minimum of historical accuracy. I already have WorldComposer. It's very cool, but obviously doesn't place any trees. I need to be able to add them, hopefully. Also the area I want to simulate ( North & South-Western China) has poor satellite pics. The terrains need a lot of touchup. A terrain editor would be nice if it played well with WorldComposer or at least use the heightmaps from it. I'm a newbie at this, but I don't mind putting in the time to learn tools. I just want avoid spinning my wheels with something unsuitable. So far, Gaia looks like the best option. I would just like to know if anyone has a better suggestion for a terrain tool. Thanks for any suggestions.