Where is the documentation?

[xanhou]

Yes there is a button "API Reference" at the top of the page. I know that.
I can also find tutorials on how to implement specific pieces of functionality, no problem.
However, I am currently working with existing, undocumented, code that uses Bullet (JBullet actually, but that should not matter).
While looking at this code I find various methods of which I wonder what the details are.
So I go looking for the documentation of these methods.
Being used to java, it is logical to me that methods have some documentation describing their behaviour. Especially if their behaviour has minor details that are not described by the name of the method.
However, the API reference barely contains any of such descriptions.

Example which I encountered:
What is the difference between:
btCollisionObject::setInterpolationWorldTransform
and
btCollisionObject::setWorldTransform

The only way to find out that I know about, is to read random tutorials or chapters of a manual about Bullet, until I find parts that use and describe both methods.
This cannot possibly be the right way to find out how a library works, so how do I find out what the details of these methods are?

ps. Although I am also looking for the specific answer to the given example, I would much rather have a generic answer, that works for all methods that I may need to look up.

[Mako_energy02]

I have good news and bad news.

The bad news is that the documentation you are looking for does not exist. You get the manual, the demos, these forums, and the very, very limited doxygen documentation you've seen. That's it. Rest is trial and error, as well as source diving. For what it's worth, everyone agrees with you in that Bullets documentation is lacking.

The good news is I think I can take a stab at your specific question. I'll just add the disclaimer right now that I am not 100% certain about this, but I believe the interpolation world transform is more or less an internal member used to calculate the final transform when motion is interpolated between actual simulation steps. What I can confidently say is that the normal world transform is what you alter/query when you want to work with the objects position and orientation in almost all situations. At least that is how I am using it and it's worked out well so far.

[xanhou]

I have good news and bad news.

The bad news is that the documentation you are looking for does not exist. You get the manual, the demos, these forums, and the very, very limited doxygen documentation you've seen. That's it. Rest is trial and error, as well as source diving. For what it's worth, everyone agrees with you in that Bullets documentation is lacking.

The good news is I think I can take a stab at your specific question. I'll just add the disclaimer right now that I am not 100% certain about this, but I believe the interpolation world transform is more or less an internal member used to calculate the final transform when motion is interpolated between actual simulation steps. What I can confidently say is that the normal world transform is what you alter/query when you want to work with the objects position and orientation in almost all situations. At least that is how I am using it and it's worked out well so far.

Thank you for confirming my fear about the lack of documentation.

With regards to the InterpolationWorldTransform:
Strange, it is being used in a piece of code that seems to work... I will have to figure out what people intended to do there. Unfortunately they also thought it was an amazing idea to leave these kind of puzzles in their code...

[Epileftric]

[...] You get the manual, the demos, these forums, and the very, [...]

I still haven't found those! Everywhere I read "you can find that on Demos/WhatEver" but don't know where :/

[Mako_energy02]

They are available in the SDK downloads/SVN for bullet, in the folder "Demos". You can also view the demo's folder in the repo here:
https://code.google.com/p/bullet/source ... nk%2FDemos

[Epileftric]

They are available in the SDK downloads/SVN for bullet, in the folder "Demos". You can also view the demo's folder in the repo here:
https://code.google.com/p/bullet/source ... nk%2FDemos

What n00b my self... I've seen one of those demos, I didn't know they were all there. THANKS!