[osg-users] Float vs double in BOUNDINGSPHERE and BOUNDINGBOX

[Robert Osfield]

Hi Maxim,

The default to BoundingBoxf and BoundingSphref is partly a historical reason.

Scene graphs traversals are memory bandwidth limited so you only want
to pay for the extra memory size if there is specific value in doing
so.

Robert.
On Fri, 29 Jun 2018 at 05:00, Maxim Stere <osgforum at tevs.eu> wrote:
>
> Hi,
>
> Is there a reason why OSG_USE_FLOAT_BOUNDINGBOX and OSG_USE_FLOAT_BOUNDINGSPHERE are set to YES in cmake by default?
>
> Since most CPUs now use doubles natively and emulate floats, making float calculations a little slower, would it not be better for OSG speed and performance to have these options be set to OFF by default?
>
> Doubles would take up more RAM but what is more important for intersection speeds in OSG, RAM use or CPU number crunching?
>
> ------------------------
> Thank you,
> --Maxim
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=74219#74219
>
>
>
>
>
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