Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: romullus on 2015-03-09, 10:30:07

Title: Bitmap paging and texture filtering
Post by: romullus on 2015-03-09, 10:30:07

I've discovered that when bitmap paging is on, texture filtering has huge impact on performance. Rays/s varies drastically when filtering is on or off, when blur is set to 1,0 0,1 or 0,01, when distance from camera to object changes. It's just impossible to find optimal combination. Luckily, everything is back to normal once bitmap paging is turned off.

Not posting this as a bug, since it is strongly recomended to turn off paging anyway. Just want to remind to watch for it, as it can be pure evil.

p.s. is it possible to make Corona to check for bitmap paging and to show unobtrusive warning in VFB when paging is on?

Title: Re: Bitmap paging and texture filtering
Post by: racoonart on 2015-03-09, 10:45:32

It's not directly related to your question but I thought I'd post it anyways. I recently added a script in our shared network startup scripts folder that pops up a warning messagebox if you load max files with bitmap paging activated.
Maybe someone finds that useful. Just copy it to your "\3ds Max 20xx\scripts\Startup\" folder

Title: Re: Bitmap paging and texture filtering
Post by: romullus on 2015-03-09, 10:56:25

Thanks a bunch! I have a script which turns off paging in new scenes, but it don't help in old scenes. Now, combined with your script, i finally can feel safe :]

Edit: i think that such script must be bundled with Corona installation. Not everyone knows about bitmap paging and damage it causes.

Title: Re: Bitmap paging and texture filtering
Post by: juang3d on 2015-03-09, 13:17:26

It's not a Corona specific damage, I've suffered it with iRay and with mental Ray, it is insane, I still don't understand what is bitmap paging for (I mean in a practical way, not in a theoretically way)

Cheers.

Title: Re: Bitmap paging and texture filtering
Post by: romullus on 2015-03-09, 15:50:39

I know it's not Corona specific, but it suffers very badly from paging. I tried my old Mental Ray scene with bitmap paging on and off today and difference was very small. With Corona i can easily get to situations where difference is measured by orders of magnitude!

Title: Re: Bitmap paging and texture filtering
Post by: antanas on 2015-03-10, 17:57:40

Thanks Deadclown ! that little script is really useful (old, not my own scenes, etc.) and I more than agree with romullus - it should be included in Corona's installation by default.