Casting No Shadows

kwannie

Is it possible to illuminate a single object in a scene without having it cast shadows on everythin g behind it? I have a scene of a TV Studio stage that I am using with spotlights on the characters which I don't mind casting shadows, but other objects are hanging down off to the side as decorations that I want to illuminate without shadows. What type of lighing can I use to light single objects without casting shadows or  without disrupting the other lighting in the scene? Thanks!

AlmightyQUEST

Without doing really tricky light effects like adding lights where those objects are casting shadows, your best option in Studio is to render in 3Delight where you can set objects to not cast shadows. It should be a property in parameters I believe. But anything in the scene that is visible will cast shadows in iRay.

kwannie

I'd have to change all the character and object textures if I switched to 3Delight. So I don't think that would work  for this scene.

AlmightyQUEST

Can you render it twice then, once with the objects lit, and once with the lighting the way you want for the rest of the scene, and then combine them in an image editing program and mask in just the extra objects?

kwannie

I'm not really sure how to go about masking and I don't own Photoshop, I only have gimp. Is the a product that can remove shadows or a script somewhere?

TheKD

Not in iray, no. It's a physics based rendering engine, you cannot light something in real life without a shadow.

ebergerly

A couple of thoughts...

• If you're trying to reproduce a TV studio, then why not just light it like a TV studio would? Which probably means adding more lights to light up the unwanted shadow areas.
• If you don't want any object to interact with the background (eg, casting shadows, etc.), then you might want to render it separately (as has been suggested already I think) with the existing studio lighting, but without any background objects to make shadows on, and then composite that rendered layer onto the remaining scene with the characters? You can do that using Iray canvases, and that will just render in a layer but include the ambient studio lighting.

BTW, just keep in mind that if you do stuff that wouldn't normally be done in real life you might get viewers saying subconciously "hey, wait a minute, that character is lit real bright but there are no shadows...that's weird". 

fictionalbookshelf

If you select the item in the view port and then go to the parameters tab, select display, and change the item to casting shadows to off.

AlmightyQUEST

That only works in 3delight though.

Silent Winter

kwannie said:

I'm not really sure how to go about masking and I don't own Photoshop, I only have gimp. Is the a product that can remove shadows or a script somewhere?

Gimp works fine for this.

Are the other objects in the foreground? - You could render them separately (once for main render with those objects invisible, then once with those objects visible and everything else invisible - beware the lighting won't be perfect as objects reflect light in iray - if using an HDRI, you'll be getting back lighting where your background props would otherwise block it), save as .png, then open your main render in GIMP, go to 'Open as Layers' and open the foreground png - it'll add it on top, then go to 'export as' and save it as yourfilename.jpg (or .png if you prefer lossless).

kwannie

I really would like to try some composite work but I am doing animations so, and it is on a stage with stage lighting that moves with the character so obviously some of the back lighting will be hitting the character too. I have attached a sample of my current scene. It is a recreation of a TV Series in Japan called Night Hit Studio. The diamond shaped objects on the side are what I was trying to get light on. This is just the beginning  of the creating process I will be adding much more such as an orchestra off to the left of the singer and a few people sitting behind her and more lights of course. If you like to see a real sample og this type Night Hit Studio into Youtube. The motion is an MMD conversion.  I am having issues with the high heels using the aniblocks high offset, since that actually gives her the sliding feet effect. But it is starting OK ...........I think.  Anyway I am not familiar with the masking, canvasing or compositing process, otherwise I would l love to add some atmosphere and lense flares and fog effects on the spotlights.

benniewoodell

Studio lighting is usually mainly overhead lights for a show like that, so do linear point lights above, or spotlights, and don't have it so far in front like you have in the girl in the photo. You could also throw another light up on the surface that would take the shadow away also.

Or if you want to keep the lights how you have it because you like the look, just turn off the background/floor, set the environment to scene only, turn draw ground off, and export it as an image sequence as a PNG. Then render just the background with everything else turned off. Then download Davinci Resolve, it's free, and put the background on V1 in the timeline and put the person and whatever else you don't want casting shadows on V2 and you'll have zero shadows! 

benniewoodell

Or another idea you could do is turn the spotlights the opposite way. Make a plane and turn the color white and position it like a bounce board in front of the light a couple of feet, but angle it so the light would be reflected onto the character or whatever else you're trying to light but not get a shadow from. You'll get a wonderful soft light on her and shouldn't get any shadows. 

fred9803

I think I agree with ebergerly above. Wouldn't it look weird if part of your scene that should be casting shadows, wasn't casting shadows?

kwannie

Great suggestions, I tried it but I am getting a lot more graininess with the bounce board is there a way to reduce the graininess without increasing the max samples. Like I said before I'm doing animation so increasing max samples would add way too much render time.

Kitsumo

Nevermind. Misread post.

benniewoodell

Try increasing the luminescence to get rid of the graininess, or add another light and bounce it. I do animation too so I get not wanting to add samples! There's a sweet spot to make this work perfectly, just gotta play a bit and you'll find it :) Can't wait to see it!