Number of Prepasses

[ultra]

Hullo Flipside

_I am kinda confused now, Gonzalo once explained that to increase the resolution, say from 800x600 @ -4-2 to 1200x1000 it was recommended to lower the irradiance map passes say to -3-1, but in our last post you say the opposite is better ??

thanx

mauarduz

[GoncaloP]

I never said that!? The Flipside explanation is correct

Gonçalo

[flipside]

I'm not sure about the math... -3,0 for 800*600 how this translates to resolution for -4,-1.

But i'm sure if you render at higher resolution you can decrease the irradiance settings. If you would render at 800*600 with -3,0, this means high quality and an irradiance map calculation time of X.
If you want the same irradiance map calculation time for a 1600*1200 image, you need to lower your settings (for example to -4,-1). This way you will also have the same irradiance quality (detail) as in the 800*600 image.

If you would increase it (to -2,1) for a higher resolution image, the calculation would be way longer and the irradiance map quality will be much better than you had in your smaller resolution image.

I think it goes as follows:
-4=1/16
-3=1/8
-2=1/4
-1=1/2
0=1/1

So, irradiance passes for 800*600 @ -3,-1:
-3: 100*75 [=(1/8*800)*(1/8*600)]
-2: 200*150
-1: 400*300

If you want the same for -4,-2:
image of 1600*1200
-4: 100*75 [=(1/16*1600)*(1/16*1200)]
etc...

[ultra]

Thank you for the answer Flipside,
I guess I WAS confused,
sorry for that Gonzalo, missunderstood