Shadow Question
Posted: 10 July 2018 05:41 AM   [ Ignore ]  
Total Posts:  142
Joined  2012-01-06

Hello Sassi

I understand your concern with soft shadows, but I would like to ask about an example where I can’t get the result I want without them.
See the project below, a single spotlight set as shadow catcher, and a plant in front of a plane.  With area shadows the shadow is to blobby, impossible to read.  With hard shadows it is not even worth mentioning.  But with soft shadows it start looking like the shadow of a plant on a wall.
What am I doing wrong with the area shadow option?

https://www.dropbox.com/s/aq73hh164pzb0ip/PLantShadow_1.c4d?dl=0

Thank you!

Profile
 
 
Posted: 10 July 2018 06:45 AM   [ Ignore ]   [ # 1 ]  
Moderator
Avatar
Total Posts:  5850
Joined  2011-03-04

Hi Alex,

The fastest way to “demo” it is just by pointing to the manual:
https://help.maxon.net/us/#OLIGHT-LIGHT_GROUP_SHADOW
Pretty much the main problems are well documented. What is not documented is more or less a logical follow through of the documentation. So, not a critique on the manual, more a demo of its concerns.

To your scene: Well that is a still that you shared above. Not your typical work either, right? If the background would move away, just a simple plane. The shadow would be the absolute the same, if you place the camera at the light source. No change, absolute un-natural.
However the main artifacts will show if the object light distance or relation changes. As it is just based on raster points that will create a texture, then, it might be for a while between certain points and then between others for a while.
A more typical set up would be rotation, where the light is static and the object moves. The Soft-Shadow has a lot of trouble to keep things without blotchy flickering., or lets call it Lava lamp aesthetic.

Anyway, tight gaps between objects, the missing qualities of natural shadows and the inability to cope with motion set this option apart from any other light source in Cinema 4D. The biggest advance is given when nothing moves, and no small gaps are presents or the whole duration, then a single calculation can be used for an endless amount of images. I think there are better options then, baking the shadow for example.

I have put three rough examples based on my three points in this link:
https://www.amazon.com/clouddrive/share/qyJ7T3hZMIiKAlYppb1AbqpuVkoksBAn9HLnXJPHsgS

I find it, besides its shortcoming, that the aesthetic it often provides has that ‘90ish-CGish aesthetic. But that is just a question of taste perhaps. If you’re happy and nothing bites your project, use it. I always think that after a while no one really cares how long it took to render, but your are stuck with the results perhaps endlessly.

In the scene you had shared in a different thread, the main body is 100% reflective, hence it doesn’t take any soft shadows, and Hair (default) has no concept of soft shadows at all, it is a volume effect that doesn’t care about this. My concerns were more:if you switch to polygon hair.

Anyway, one of the most natural qualities, is the fact that with distance it gets more blurry. Perhaps set the parameters hight for the soft shadow. Check the area shadow as comparison
https://www.amazon.com/clouddrive/share/rzL3aRptPUxBg4eQtSvYg9M2JDNp10waiXRKx6Cje12

My best wishes

 Signature 

Dr. Sassi V. Sassmannshausen Ph.D.

Photography For C4D Artists: 200 Free Tutorials: Texture, Panorama, HDRI, Camera Projection, etc.
https://www.youtube.com/user/DrSassiLA/playlists

Profile
 
 
Posted: 10 July 2018 07:31 AM   [ Ignore ]   [ # 2 ]  
Total Posts:  142
Joined  2012-01-06

Hi Sassi

Totally understand your point.  Your examples are great.  One thing that is clear is that you need to add a lot of samples to the area shadow for it work nicely, but it is indeed a MUCH nicer result!

Thanks again!

Profile
 
 
Posted: 10 July 2018 07:39 AM   [ Ignore ]   [ # 3 ]  
Moderator
Avatar
Total Posts:  5850
Joined  2011-03-04

You’re very welcome, Alex, thanks for the question.

Yes, the area shadow from an area light source might be one of the more demanding lights in the toolbox. Perhaps a good management when it is really in a close up and when not might help to micro manage it. Besides, sometimes baking shadows might be advised as well, or just camera map things back on. Keep it creative.

My main intention is certainly that any work is future proof that we discuss here. The changes to Rec 2020 and its HDR version might be the largest shift in quality in a while. Thinking back to the HD times, where we were half the way to a new standard, and the image needed sharpness as default in many cameras. With 6K or even 8K the new standard as capture format, I guess it doesn’t take long that a “normal audience” get used to much more.
Hence why I throw in sometimes my concerns, like color management, or what will be a standard at one point.

Anyway, I digress. grin

ENJOY

 Signature 

Dr. Sassi V. Sassmannshausen Ph.D.

Photography For C4D Artists: 200 Free Tutorials: Texture, Panorama, HDRI, Camera Projection, etc.
https://www.youtube.com/user/DrSassiLA/playlists

Profile