double precision

[neveu]

Quick newbie question: does OGRE have (or is it possible for OGRE to have) double precision position information in a scenegraph?

[Robomaniac]

yup, just change the typdef of Ogre::Real to double and it should work

[IoN_PuLse]

Although DirectX and OpenGL as far as I know only work in single precision, so I'm not sure if there is any point

[:wumpus:]

Yes, it's possible, and it's only a bit slower. And yeah, OpenGL and DX still only get the values in single precision but that shouldn't matter for rendering anyway. The scenegraph can be in double precision.

[Van]

We use double precision in our application. The frame hit was very minimal (like two tp five fps) - not even noticeable.

You have to change a #define flag in your OgreConfig.h file and recompile the Ogre library. Word of caution though, if you plan on using any other libraries make sure they support doubles and some of the ogreaddons require lots of modifications to support double. For some reason some of those authors used a float declaration instead of using Ogre::Real.

BTW, we also use the Newton Physics engine which also supports a double precision. Newton here: http://www.physicsengine.com

[sinbad]

yup, just change the typdef of Ogre::Real to double and it should work

No, don't do that. The correct way to do this is to change OGRE_DOUBLE_PRECISION in OgreConfig.h to 1.

[DFooz]

1) Is Ogre SDK builded in single precision?
2)If yes, how can I set double precision without recompiling?
Just set in OgreConfig.h, isn't it:

Code: Select all

#ifndef OGRE_DOUBLE_PRECISION
#define OGRE_DOUBLE_PRECISION 1
#endif

Thank you.

[bstone]

You have to recompile it.

[spacegaier]

And you can also set that pre-compilation macro via CMake I think.