Haykel BEN JEMIA wrote: > Marcus, > > how did you do the choice? Did you compare OpenSG with other SG-APIs? > If yes, what features/functionalities were decisive for choosing > OpenSG? This could be a starting point for a feature list/comparison > chart. >
This won't be much of a feature-list comparision, I'm afraid. I based the whole thing more on gut feeling (since I was a rather fresh-out-of-college employee with grand ambitions on how to do proper programming, I had a lot of subjective feelings about how some ppl chose to write their APIs ;-). I did this summary in Jan/Feb last year, so things might have changed since hen. I was looking for something which had: - a good solid framework into which there's gone some serious thinking (Dirk's 'design goals for OpenSG'-paper which is actually available on opensg.org, if you dig a bit, convinced me that there was some serious brains behind this. I also liked how things were put together. It often did match how I would do it, or rather, how I would imagine I've done it if I had the same experience and knowledge.) - a just-enough abstraction of OpenGL (move out glXXX() calls but retained fine control & full feature set (I really like the viewport/window abstraction and the chunks.) - supported GLSL properly (this wasn't easy back then) - source code attached (need to see how things work and debug crashes due to me sending bad data) - good support (OpenSG's newsgroup is amazing, many commercial SG's are far worse, so why pay more for less?) - some kind of multithreading support (which we will eventually use, since the whole computer industry is heading that way. Currently, we do multithread our physics calculations, but not the rendering, and I am still wary on making almost every class we have a FieldContainer and collecting change-lists, so we have our own lightweight aspect-system and do things a bit more manually, for now.) - low price (it was intended for just one small project in the beginning) OpenSceneGraphs's website was too messy and I couldn't get my head around their design (the whole thing didn't look 'serious' enough, I think my impression was). I didn't make a thorough check of this, since I originally was recommended OSG but ended up looking at OpenSG and choosing that. After going back and looking at OSG, I still think I made the right choice at the time. Coin's (or other companies, such as TGS/Mercury) OpenInventor clones suffered from OpenInventor's way of handling GL state (nodes' state affect their siblings, not just their children. I don't agree with doing that and shuddered at the bugs it could give, given I'm not used to working with that model.) Performer had lousy support and had a rather arcane architecture (which I'm sure worked nicely on SGI-systems back in the 80's or early 90's). Also, most of their features do not work on Windows. Optimizer/Cosmo3D has just gone out of business. Their field-binding is a bit odd as well, and there are some remaining memory leaks which cannot be fixed. WildMagic is nice (I used that to teach games programming for a couple of years), but is failing on support and new development, since the author keeps quite strict control over it and his original book is not selling by heaps and bounds anymore. It is also more of a research system which demonstrates concepts nicely (and has an amazing math-library), but has been a bit slow in adopting performance-critical features needed for real-world apps. NVSG is pretty new, might have potential, but was not really mature and the support was lousy (no newgroup/form what I could see). But at least I got a response four weeks later apologizing that my e-mail got lost (I didn't get much of an answer either). Also, it is controlled by Nvidia, so I had no idea what kind of commitment there would be over long term (since they didn't advertise it much, nor could I find a proper license.) Cheers, /Marcus ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Opensg-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/opensg-users
