Jump to content
  • Advertisement
Sign in to follow this  
Jarwulf

Maya and PhysX

This topic is 2559 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I need a way to convert maya files to work with physX specifically by turning them into nxs, what I'm told is physX's main format. The maya physX plugin does not convert to this format for some reason just intermediate formats I don't know how to use. There are tools to do roundabout conversions (curiously almost all using Ogre3d formats for some reason) but these are extremely buggy abandoned projects.

There is little to nothing I can find on the web to this. Its like twilight zone. If a way exists it must be one of the best kept secrets in the history of game design. Virtually every result I can find is simply a past question asked by me and never satisfactorily answered. There is virtually no mention of nxs itself, its as if the format doesn't exist. Given how widely used maya is and how popular physX is I find it hard to believe that nobody in the history of the world has ever gotten maya to work with physX.

Does anybody know of a way to do a conversion? What is the usual way to use maya files with physX? Or am I mistaken and maya cannot be used to design meshes for physX games like google results seem to indicate?

Share this post


Link to post
Share on other sites
Advertisement
I think the general consensus from me googling around is they suggest people using bounding boxes/circles for physics instead of doing a full mesh triangle export.

If this is not possible I think the only real solution was the one you were reading with the OGRE export to flower xml, then to nxs.

Share this post


Link to post
Share on other sites

I think the general consensus from me googling around is they suggest people using bounding boxes/circles for physics instead of doing a full mesh triangle export.

If this is not possible I think the only real solution was the one you were reading with the OGRE export to flower xml, then to nxs.


I see countless demos, simulations, and games where collisions are definitely not this simplistic. I don't see how simple boxes would still be feasible once you get past a certain complexity. Take a halfway realistic character or a reasonable organic platform or object. Are all these AAA titles using collision boxes without us knowing? Nobody's invented a way to directly cook a maya mesh for PhysX? I'm seeing nearly the same dearth of information for Max too. Nobody in the history of the products has ever used max or maya with physX enough to come up with an algorithm or tool for conversion ? really?

Share this post


Link to post
Share on other sites
Well, many times it will be many bounding spheres/boxes that approximate the geometry (or surface), rather than say the single volume that encapsulates the whole object. For example, I remember a few years back exploring the modding community for an RTS called "Empire at War", in the model viewer for the game's model assets, a star destroyer was approximated by a bunch of oriented bounding boxes (or something to that effect).

As far as physics is concerned, it may be those simpler primitive shapes. Or it may be something more complex. I do know Valve's source engine uses something called a collision mesh, which may not necessarily be a simple bounding primitive.

Share this post


Link to post
Share on other sites

Well, many times it will be many bounding spheres/boxes that approximate the geometry (or surface), rather than say the single volume that encapsulates the whole object. For example, I remember a few years back exploring the modding community for an RTS called "Empire at War", in the model viewer for the game's model assets, a star destroyer was approximated by a bunch of oriented bounding boxes (or something to that effect).

As far as physics is concerned, it may be those simpler primitive shapes. Or it may be something more complex. I do know Valve's source engine uses something called a collision mesh, which may not necessarily be a simple bounding primitive.


Yeah I know that is one way. Still that does not convince me that all the games, demos, and simulations I'm seeing are actually cleverly disguised bounding boxes and spheres.

I was under the impression that standard practice in high quality collisions/physics is to use a simplified collision meshes obviously not as detailed as the visible polygons but still a bit more than a primitive. And where would you design these meshes if not maya and max? Am I mistaken since this seems surprisingly exotic to so many people?

Share this post


Link to post
Share on other sites
A full mesh collider is very inefficient in practice, and is generally only used for terrain colliders. For other objects, the shape is approximated as mentioned previously using multiple primitive collision volumes. Furthermore, characters are often granted pill colliders, which are essentially a mix between two sphere colliders and a cylinder collider. these, when put together, form a pill shape. It's a good, efficient shape for a character.

Share this post


Link to post
Share on other sites

A full mesh collider is very inefficient in practice, and is generally only used for terrain colliders. For other objects, the shape is approximated as mentioned previously using multiple primitive collision volumes. Furthermore, characters are often granted pill colliders, which are essentially a mix between two sphere colliders and a cylinder collider. these, when put together, form a pill shape. It's a good, efficient shape for a character.


Okay, but that means there are collision meshes out there simplified but still approximating the shape of the visible mesh. And the meshs are designed in maya/max right? How are meshes being moved to physX then?

If nobody knows how to do it from .mb to nxs how about xml to nxs or nxb to nxs which are the formats the physX for maya plugin exports. Or am I just wrong and nxs is not used at all?

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

GameDev.net is your game development community. Create an account for your GameDev Portfolio and participate in the largest developer community in the games industry.

Sign me up!