It seems Most of the keyshot users are rendering for final output in Photoshop. So this might seem a little off, but it's definitely what I'm after, so lets see how close we can get.
disclaimer: render layers are great, but if you look Really close, you get a halo of half missing pixels. So, not great for final production in this case.
I need 3 layers:
-Final render
-Ground reflection
-Ground shadow
The final render, of course, may consist of several different composite layers. But when I hand off the final files for people to add to graphics, they need the final render, the reflection, and shadow as separate files. Illustrator won't read that you've used the shadow layer as multiply, and won't read what you might have done for your reflection layer either.
So then there's the problem. It's already a lot of work for shadows, because your shadows aren't black unless you render on black background, but it doesn't get sampled properly if it's rendered on black. So you pretty much Have to render your shadows on white. I've got a workflow for that, and although it's annoying and I wish Keyshot just had a tool for saying, "give me a ground shadow all by itself" that's fine.
And when I say Just the ground shadow, I mean not just clipping the edge of the shadow. It needs to go clear under the product.
"What's this halo thing your talking about Andy?"
I'm glad you asked. There's an easy way to check that out, completely outside of Keyshot!
Create yourself a photoshop file, 1200 square. Make the background white. Create a new layer, and make that red. Now make a big selection at an angle and select about half of it. Hit Ctrl+J to duplicate that to a new layer. Make that same selection again by holding Ctrl (option on mac?) and clicking on the thumbnail. Invert the selection (Ctrl+Shift+i), and create a layer mask, or hit ctl+J again and just delete the solid layer.
Looks fine? Maybe, zoom in to 200% just to be sure.
OH NO!
This is what happens with Render Layers in Keyshot. So the best practice is to always keep your full render underneath the render layers to keep those half transparent pixels hidden.
So shadows? Well, that's a problem. Because your shadow IS transparent. So you'll get this nice little halo between your product, and the shadow. This is why I don't use render layers for shadows or reflections.
OK - back to the issue: You can render the product, and you can render the shadows by themselves by applying an emissive material to everything and making it invisible to camera. This trick has been around for some time now. You just have to jack up your refraction rays quite a bit first. No problem.
But the reflection? This is more tricky.
There are a few options, but I've not been thrilled with any of them.
You can get a reflection without a shadow, if you render with the environment reflection. But the limitation there is you can only get a crisp reflection.
If you add a ground plane you can get a reflection with blurry reflections, but you can't render without a shadow. You can change the color of the shadow to white, but that just literally changes the shadow color to white, it's not shadow intensity.
So the best I've found, if you need blurry reflections, is to render on black background, with black shadow as a separate pass. Now, you still have the "halo" issue because you can't get reflections under the product, but it's not a Huge issue for reflections. I have a way to fix that in post for reflections.
The problem? Transparency. If you want that, and blurry reflections, you'll have to render a second pass. You can render your entire object as flat white, with the reflection plane and a black environment with no lights. This way you get a selection of just your object, and the blurry reflection. This is the same method use for creating selections when you render with DOF active. It's also the reason I do my best to Not render with DOF active.
I do the same thing to get transparency through objects. Just do a second render with something like a flat green plane in the background (use a color that isn't likely to be in your product) and use color selection to create a mask. It isn't entirely accurate, but if it looks believable, then no one will know.
If it looks good, it is good. But I'd sure like to keep my time down. I'm a consultant. Realstically everyone works hourly, but people see costs and think of how much it is per image. That also means, if I can be twice as fast as "the next guy" then I'm either making more money, or delivering better quality.
If you folks have some advice on how to achieve the ground reflections, blurred, in a more efficient way, I'm all ears.
And if the Luxion folks see this, and are able to disable ground shadows on the ground plane? Well, that would be super.
