Product rendering in a Clear tub with a carton wrap too dark

[ldichiara]

Hi all - I have a rendering that I am trying to set up which is basically a carton with one side open that contains a clear tub with circular products inside. I need the product to be visible; because the carton is enclosing the product I am getting VERY dark shadows;
I turned off self shadows to see if this helps but that completely blows the product out with too much light. Any suggestions on what to try? I've played with the illumination settings and shadows to see if I can get a happy medium haven't found it yet.
I've tried the product setting which is my usual go to, as well as jewelry and caustics. Caustics give me better lighting visibility but I am getting a moire pattern that is not desirable.

Thank you

Lenny

[TGS808]

Try adding a plane to your scene, using it as an area light and turn off "visible to camera" and "visible in reflections". You can scale it, adjust the brightness of it and position it directly in front of your product (if necessary) to light up those spherical items. It's a bit of a "cheat" but also one of the big benefits of working in the virtual 3D world vs doing this with real lights and cameras.

[andy.engelkemier]

clear objects are tricky. They Do cast shadows, but the shadows are a bit extreme in most 3d software. But in the real life it's also focusing some light through it, with caustics which are Very expensive for rendertime.

So Cheat!
You can make the clear object cast no shadow. You have to switch keyshot into experimental mode, unfortunately. So edit the XML file in the keyshot Public Documents folder. It should be KS9Settings.xml or something like that. Search for experimental and turn that to true. Save.
Open keshot back up and you'll have access to a few more things. Avoid the generic material. That one is very experimental.
But you now have the Ray Mask utility. That's what you want.

Open the material graph and create a Ray Mask node. Drag that into the opacity of your transparent material. Double click the ray mask node to show the properties, and uncheck Visible Shadow.

Shadow rays will now pass right through it.

It's still going to be pretty dark without shooting light more directly in there, like someone else mentioned. Keyshot Mostly works on HDRI lighting which just shoots light toward the product from a sphere. That's pretty terrible for lighting the inside of things. Interior mode may help, but render times will be painful. Start with that cheat and see how far it gets you.

Consider rendering twice also. Once for the proper exposure for the outside, and once for the inside, and composite those two together.
Also, don't go very far with lighting without at Least changing the package material to the correct material. It looks like it's a diffuse material?
And make sure to never use the default environment for this kind of thing. It very evenly lights everything. So when you create materials there, they will never look how you would imagine, unless you imagine things floating in the middle of a well lit lighting tent. Double check with one of the real environments and bounce back to a studio. If it looks good, it is good, but if you're really far off from an accurate material then every small change becomes a fight to get it back to looking how you wanted it.

When I'm creating materials I bounce between studios I make and real world HDRI's so I can double check things like roughness. If all your lights are soft, you don't need to worry about roughness much. But then you put it in something with point lights and all your materials look wrong....because they are.

Good luck. Getting keyshot to light inside of boxes is a Very big challenge. Hopefully they will choose to add portals one day to help out.

[ldichiara]

Thanks Guys