KeyShot Forum

Technical discussions => Lighting => Topic started by: imprincevince on May 15, 2020, 11:29:40 pm

Title: Workflows For Ground Shadow Control — Explanation of Ground Settings?
Post by: imprincevince on May 15, 2020, 11:29:40 pm
Hi KS Forum!

Curious what people's workflows are with shadows.

Currently I'm doing Edit < Add Geometry < Add Ground Plane < Occlusion texture into the Shadow box and controlling from there + rendering out the shadow and object on their own layers [Will Gibbons posted a tutorial pretty recently on his workflow]. This has been my preferred way to get realistic, clean, editable shadows.

I am a bit confused on the "Ground" settings under "Environment". I've noticed I get different results depending on if the "Ground Shadows" box is checked or not under Environment < Settings. If I make "Ground Size" 1mm [as small as possible] and then turn on "Ground Shadows", the scene will actually be brighter than if "Ground Shadows" was unchecked.

To me, that seems a bit counterintuitive to turn on "Ground Shadows" but then your scene gets brighter.
+ attached a PNG of a MacBook from Apple's website with a clean, controlled shadow. The shadow darkens the bottom of the MacBook but is not necessarily darkening the entire scene. The shadow also ends before the edge of the page so that you can put the rendering on different colors, scale the size, move it around, etc [this is solved by Occlusion texture].

_V
Title: Re: Workflows For Ground Shadow Control — Explanation of Ground Settings?
Post by: richardfunnell on May 18, 2020, 05:22:53 pm
+1 - would love to hear some feedback from the dev team on this one :)

I've run into the same issue with Ground Shadows on/off and making the "Ground" super tiny, but would love to know *why* it behaves this way!

Title: Re: Workflows For Ground Shadow Control — Explanation of Ground Settings?
Post by: INNEO_MWo on May 18, 2020, 10:51:50 pm
Hello.


If you use the occulsion node into the opacity channel (ground material), then you should get no effect if ground shadow is on or off.
Title: Re: Workflows For Ground Shadow Control — Explanation of Ground Settings?
Post by: imprincevince on July 11, 2020, 10:14:27 am
Bumping this thread again for new thoughts!

Hello.

If you use the occulsion node into the opacity channel (ground material), then you should get no effect if ground shadow is on or off.

Thanks for the comment, looking for a bit more detail into the calculations of ground shadows and best practices. There're a lot of options for ground shadows but I don't think I've seen a consistent / best practices approach.

1. Under your lighting environment check the "Ground Shadows" box
2. Check "Ground Shadows" box + add ground plane
3. "Ground Shadows" unchecked + add ground plane
4. "Ground Shadows" unchecked + add ground plane with Occlusion Shadow

+ additional question of how do you use "Image Style" when you have a ground plane in the scene? The adjustments you make also adjust the ground plane so you can't keep it pure white / transparent [even when you check the box for "Background Color"]

+1 - would love to hear some feedback from the dev team on this one :)

I've run into the same issue with Ground Shadows on/off and making the "Ground" super tiny, but would love to know *why* it behaves this way!

Hey Richard!
Title: Re: Workflows For Ground Shadow Control — Explanation of Ground Settings?
Post by: imprincevince on August 18, 2020, 04:25:30 pm
Bumping this, would still love to hear from some people :)