Page 1 of 1
Help! Effective setting when using hdri
Posted: Tue Jun 28, 2011 4:32 pm
by tuts3d
Hi
I'm trying to use hdri to light my architectural exterior scene but my problem is that it looks grainy even after 16000 pass. I'm happy with the lighting effect per se, it's just those grain that I cannot remove. Is there a technique on setting it right to avoid this? Could it be cause by the building having aluminum cladding all around? Time is of the essence so a quick reply would be greatly appreciated.
I used one of the images from openfootage if that info is of any help. Unfortunately I cannot post any screen shots as it is an ongoing project.
Thanks in advance.
Re: Help! Effective setting when using hdri
Posted: Tue Jun 28, 2011 4:41 pm
by Mugga
Hey,
you could try to render your scene in a higher resolution, maybe twice the size you have now.
And when finished scale it down in Photoshop or whatever program you are using. Maybe this will help.
Re: Help! Effective setting when using hdri
Posted: Tue Jun 28, 2011 4:45 pm
by tuts3d
Thanks for the tip but what would you suggest in terms of dimension if it needs to be printed on 24in x 36in?
Re: Help! Effective setting when using hdri
Posted: Tue Jun 28, 2011 11:09 pm
by tuts3d
No other suggestions?

Re: Help! Effective setting when using hdri
Posted: Tue Jun 28, 2011 11:16 pm
by abstrax
tuts3d wrote:Hi
I'm trying to use hdri to light my architectural exterior scene but my problem is that it looks grainy even after 16000 pass. I'm happy with the lighting effect per se, it's just those grain that I cannot remove. Is there a technique on setting it right to avoid this? Could it be cause by the building having aluminum cladding all around? Time is of the essence so a quick reply would be greatly appreciated.
I used one of the images from openfootage if that info is of any help. Unfortunately I cannot post any screen shots as it is an ongoing project.
Thanks in advance.
The problem is very likely that your light source in the HDR image is too small. Maybe try to blur the area around the actual light source (usually the sun) to make it a bit more wider. Also please try the PMC test build and let us know if it works better with that one.
Cheers,
Marcus
Re: Help! Effective setting when using hdri
Posted: Wed Jun 29, 2011 12:10 am
by tuts3d
ok thanks, will let you know how it works.

Re: Help! Effective setting when using hdri
Posted: Wed Jun 29, 2011 11:30 am
by Jaberwocky
tuts3d wrote:Thanks for the tip but what would you suggest in terms of dimension if it needs to be printed on 24in x 36in?
in answer to that question
10800 x 7200 pixels at 300 pixels per inch should get you to a 36" x 24" picture for printing.
300 PPI being optimum. I sometimes go down to around 240 PPI if the render is taking to long.
Re: Help! Effective setting when using hdri
Posted: Wed Jun 29, 2011 4:36 pm
by tuts3d
I guess the math is straight forward but will my ram and card memory take the load? Hehe... do you think 12gb Ram is good enough or do I need to add more?
Re: Help! Effective setting when using hdri
Posted: Wed Jun 29, 2011 4:38 pm
by tuts3d
BTW, thanks for the tip Aabstrax! Blurred the sun in the HDRI map a little and the noise is all gone!