Bullet and Character Controller

KungFooMasta · Post by **KungFooMasta** » Tue Nov 11, 2008 7:51 pm

Has anybody had any experiences using the recently added (August, Bullet 2.70) Kinematic Character Controller?

I'm currently using PhysX in my project, but I've found what I think is a bug in the code. More importantly, ever since Nvidia has taken over PhysX, I have not received any response in email from Nvidia PhysX team, and am unable to get my forum account activated.

If you've used the Kinematic Character Controller from Bullet 2.70 onward, please let me know how it performs. And just to clarify, the bug I see is not related to PhysX character controller, but not having access to the source, forcing me to use vs2k5, and having no support in any form is kind of discouraging me from using the lib.

beaugard · Post by **beaugard** » Tue Nov 11, 2008 8:34 pm

I haven't tried it, but gathered from posts on the Bullet forum that it's in a pretty early state, if not unusable.

See this recent thread, for example:
http://www.bulletphysics.com/Bullet/php ... f=9&t=2573

KungFooMasta · Post by **KungFooMasta** » Tue Nov 11, 2008 8:51 pm

Wow, it seems like its in the very early stages. Guess I'll have to wait longer and re-evaluate my situation when the Character Controller matures some.

reptor · Post by **reptor** » Tue Nov 11, 2008 10:11 pm

KungFooMasta wrote:forcing me to use vs2k5

So how exactly does it force you to use vs2k5 (Visual Studio 2005)?

I am using PhysX with Visual C++ 2008 Express Edition and have this far had zero problems. I didn't use every feature of PhysX yet but the things I have tried have worked.

I am interested to hear what forces you to use VS 2005 with PhysX.

KungFooMasta · Post by **KungFooMasta** » Tue Nov 11, 2008 10:26 pm

I try to minimize compatibility issues between libs, so I don't want to mix vc9 libs with vc8 libs because it may result in odd behavior. Just because you haven't encountered any issues doesn't mean there aren't any.

http://www.ogre3d.org/phpBB2/viewtopic.php?t=44832

If PhysX SDK was built with VS2008, or we had the source to build from, this would be a non-issue.

reptor · Post by **reptor** » Wed Nov 12, 2008 12:51 am

Well, in that thread, in which I also participated, I said that a person from nvidia says that VS2008 should be fine.

If they think it should be fine to use with VS2008, then it should be OK

And as far as I haven't seen any problems, then there are no problems

From that other thread I get the impression that you didn't actually have any problems, you just thought that there could be problems

playing it safe is fine of course, but when the nvidia sdk documentation speaks of "If you are using a compiler other than VC++ 7 or 8, or if you would like to create a new project using the SDK, set it up as follows:" and a person from nvidia says that "should be fine". And if you have not had any problems, then what more do you need to convince you that it works, I am wondering *me scratches head*

So, to sum up what I am thinking, that comment might have been a bit unfair towards ageia/nvidia physx as you have not provided anything to show that you actually have had problems with using PhysX with VS2008. How are they then forcing you to use VS2005 is something I don't understand

Sorry, I don't want to drag this off-topic. Just thought it's an unfair comment, given that we have zero evidence that you have had problems with PhysX+VS2008.

KungFooMasta · Post by **KungFooMasta** » Wed Nov 12, 2008 1:15 am

There is nothing unfair about it, it would take a negligable amount of time for them to download a free copy of vs2008 express and compile an SDK using vc9 compiler.

I did some searching for mixing vc8 and vc9 libs, not much comes up, thats why I posted in the back to basics thread. As another member pointed out, there are some potential issues, especially when creating memory in one library, using it and managing it in another library. I'd rather not add to my list of things that I can't do. From a quality stand point (I work as a Software Engineer in Test), your specific use combined with the unofficial words of an nvidia staff member are not enough to convince me I won't have any strange or bizarre bugs in my game that I can't debug. Sorry, but you can't speak for everybody when saying its an acceptable risk to mix vc8 and vc9 libs/dlls together. When nvidia officialy says it supports vc9 and/or hands us an sdk made with vc9, then users can switch knowing they can receive support if they have issues. Then again, nvidia phsyx team isn't doing much on the support side these days.

Akinz · Post by **Akinz** » Wed Nov 12, 2008 1:28 am

http://developer.nvidia.com/object/phys ... notes.html

Supported Platforms

...

Development

* Microsoft Windows XP
* Microsoft Visual Studio .NET 2005
* Microsoft XBox360 development tools:
o November 2007 XDK (v6534)
o Other versions of the XDK might be supported by request
* Sony Playstation 3 development tools

If somewhere on that page it said Microsoft Visual Studio .NET 2008, then I would say it's safe. Until then, for a professional quality product, I do not think it's safe to assume that just because an "Nvidia guy" said "should be fine" on the forums that you won't have any problems.

In terms of support, I filled out an application to become an Nvidia PhysX developer about a month ago and have not heard anything. I have also signed up for a couple forum accounts in the past few days (using a free e-mail account and a company e-mail account) and have not received the activation e-mail that "is sent within 10 minutes (usually instantly)".

They're not forcing the use of VS2005 but they are definitely not supporting the use of VS2008.

reptor · Post by **reptor** » Wed Nov 12, 2008 3:11 am

Well, part of my reasoning in my previous post, which I left out thinking it is "unimportant" to mention, was that I doubt that KungFooMasta is releasing a game anytime soon. I think there is plenty of time for nvidia to release a VS2008 SDK before KungFooMasta is anywhere near releasing anything resembling a finished game.

Of course I can't know what exactly you have done, I am just basing this opinion on what you have shown here of your work, and my estimate is that you are in a very early phase of development.

Please don't take my words as disrespectful, because that's not what I want to express here

the point is I think you have so much time ahead to develop your game, that nvidia will release a VS2008 SDK well in that time

and after that you will still have a lot of time to verify that there are no bugs. I think this because it is clear that developing a (non-trivial) 3D game is a huge job for small teams and even worse for single persons.

I can understand your argument "there is no official VS2008 support" but I think it is not so crucial especially when your project likely is in a very early phase.

I agree that they might have gone down with the support recently, their PhysX forum seems to be weirdly quiet. I hope it is just temporary and that they are just working hard, improving PhysX and its documentation... and that big changes (improvements hopefully) are coming. I don't think nvidia would first buy PhysX and then let it die so soon. Or not support "indie" game developers more than what they are doing currently. The more users PhysX has the better it is for them, commercial project or not.

KungFooMasta · Post by **KungFooMasta** » Wed Nov 12, 2008 4:38 am

Its true we don't have any releases planned anytime soon.

The versioning was a complaint, but pretty out of scope for the reason of this post. I do hope they fix their emailing system, this bug has been around for quite some time.

FYI: Filtering does not work with the NxScene::cullShapes function, which we use to perform box selection of units. Right now we grab all units and filter them out manually, but this is not ideal. Unfortunately we can't go in and fix it in their source code.. I wish we could but I don't have 50k.

reptor · Post by **reptor** » Wed Nov 12, 2008 8:22 am

Thanks for the info about the filtering. I'll keep that in mind.

Hmmm... just an idea. Could you use a trigger instead? All units which are in a trigger's zone would be the ones that should be selected. You would move the trigger as required.

If NX_TRIGGER_ON_ENTER has been triggered but not NX_TRIGGER_ON_LEAVE, then that shape would have to be inside the trigger shape. Or actually, I think NX_TRIGGER_ON_STAY could be used. Does this sound like less work compared to how you are doing it currently?

old_man_auz · Post by **old_man_auz** » Fri Nov 14, 2008 4:32 am

In case your not aware, the Kinematic Character Controller in bullet is being worked on and there are updates planned for it in the next release. I think the Bullet team tries to release once a month and its been more than a month since it last happened. I would check back frequently on their site and see what the next release contains.

Ogre Forums

Bullet and Character Controller

Bullet and Character Controller

Re: Bullet and Character Controller