Digital Art Zone

 
     
Shadow Softness for Sunlight?
Posted: 03 September 2012 03:57 PM   [ Ignore ]
Power Member
Avatar
RankRankRank
Total Posts:  1815
Joined  2005-06-08

If (aside from low-intensity fill lights) I’m making cloud-free sunlight from a Distant Light using raytraced shadows, what’s the most realistic Shadow Softness number?

In the two renders below, the one with the woman walking to her car has no shadow softness, and (of course) the shadows of the palm-fronds are too hard.  In the Hulk’n'TonyBear render the shadow cast in front of him is from the broken roofline of a tall building, and although I think the shadows are too soft, since I don’t have any tall buildings (or sunlight -  it’s cloudy here) to check against I can’t tell if 0.50% is too much.

Is there an official this-is-the-Shadow-Softness-for-sunlight number?  If not, what are you-all’s preffered settings?

Image Attachments
HulkHyde08b-g1.jpgPCI20120824-05c-g1-1600.jpg
 Signature 

~

Hat-wearing member of the Bald Wizards Club

Eyebrow-Free Face Textures — A List

Profile
 
 
Posted: 03 September 2012 04:27 PM   [ Ignore ]   [ # 1 ]
Administrator
Avatar
RankRankRankRank
Total Posts:  14064
Joined  2003-10-09

Bright sunlight is pretty sharp - vegetation usually casts softer shadows because it’s moving, not because the shadows are inherently soft. It think there’s also often some refraction (or is it diffraction) around the leaf edges. In DS4.5 you might try adding a touch of motion blur to the plants - I’m not sure if that would work or not. \You could also add some noise displacement to the driveway - and for that matter, does it have any displacement for the gaps between bricks?

 Signature 

DAZ Studio Frequently Asked Questions

Index of free DAZ Studio scripts and plugins list

Profile
 
 
Posted: 03 September 2012 07:32 PM   [ Ignore ]   [ # 2 ]
Member
Rank
Total Posts:  116
Joined  2012-09-03

The sun is 150 Million km away and has a diameter of 1.3 million km. So the diameter of the penumbra would follow the same ratio, i.e. the penumbra of an object 150 meter away would have a diameter of 1.3 meter. In other words the radius of the blur is 1.3/150 = 0.0086 = approx. 0.9%

Profile
 
 
Posted: 05 September 2012 04:50 AM   [ Ignore ]   [ # 3 ]
Active Member
Avatar
RankRank
Total Posts:  803
Joined  2007-01-08

Heh, good point! ‘Should be “diameter” in your last sentence, though. Going to experiment sometime if some Sun would deign to show itself…

Profile
 
 
Posted: 05 September 2012 07:54 AM   [ Ignore ]   [ # 4 ]
Administrator
Avatar
RankRankRankRank
Total Posts:  14064
Joined  2003-10-09

The atmosphere will also add some blurring, depending on thickness, humidity perhaps, and dust.

 Signature 

DAZ Studio Frequently Asked Questions

Index of free DAZ Studio scripts and plugins list

Profile