nyc01, on 29 March 2013 - 03:30 PM, said:
There are game engines out there now that are written with the terrain and associated algorithms running completely on the GPU. They are also able to render unlimited visibility and detail ranging from thousands of kilometers down to centimeters while all along maintaining excellent performance.
Again it all comes down to how well the game engine is written to utilize system resources.
OR uses the XNA toolkit and therefore uses whatever routines come with it. There is little use talking about partucularly commercial tool kits as its VERY likely they would require the developers to sign a non disclousre agreement and therefore we would have an excellent chance of losing OR's "openness". Which would be a major tragedy.
Open source development is usually done by volunteers with lives to lead, that have limited funds to spend on the development and have particular programming knowledge. It may be worthwhile to stress here that a trainsim is one of the most difficult sims to work with as it requires a __GREAT__ deal of detailed knowledge of railways and physics. It appears from experience over the last 10 years or so that its very difficult to get someone with such knowledge AND have top up to the minute 3D programming experience.
Another point is I have yet to see any demos on the net that show that a particular "engine" is __FAR__ better than another. One point about doing as much as possible on the GPU, its not easy to get data back to the CPU. The 5th edition of the OpenGL superbible and also the OPenGL Programmers guide both say this MUST be taken into account. Its little point in handing the processing off to the GPU if one has to calculate a parrameter in parallel with it in the main processor. One has to chose carefully what one can hand off to the stream processors in the GPU.
In my own work I have tried 4 different 3D gamming toolkits and while they are relatively easy to use and some do terrain that looks nice. I have yet to use one that is faster than using "tiled" terrain done using the standard OpenGL library calls. It does take somewhat more effort but once the terrain and object display routines are done
one is free to work on the trainsim proper.
If OR ends up good eye candy with poor/limited train simulation and/or handling it WILL have failed.
THe open rail devs __ARE__ doing a great job.........
Lindsay