Screen-Space blur for shadows.

[snowballvfx]

So this may sound a bit weird, but what I'm trying to achieve is blurred shadows and shading for a Toon style render. I'm not talking about soft shadows, rather shadows that are being blurred in a 2D way.

There are a couple of directions I'm looking at. The shader is a simple self-illuminated material with a falloff set to shadow/light. So one way will be to somehow blur the falloff and get a blurred shadow line. Another way that I thought about was using some kind of a post render effect to blur only the lighting information. Unfortunately I haven't found solutions for both of these options.

Mind you that I'm trying to get this effect straight from Max. This is obviously very easy to do in post by blurring a lighting pass and compositing it in. Which is exactly what I've done in the attached example.

If anyone has an idea on how to achieve this we would appreciate it a lot!

Thanks!

Untouched Render


Blurred shadows in Comp

[Morbid Angel]

You can place a falloff texture in light/shadow mode and setup the blurring in it the same exact way.

[snowballvfx]

You can place a falloff texture in light/shadow mode and setup the blurring in it the same exact way.

You mean by creating a curve that gives some limited gradiation?
Unfortunately this doesn't give the same effect as it can expose the volume of the 3D mesh. Basically making it look more 3D instead of flat 2D. This is why I'm looking for a 2D based solution. The Falloff by itself is not enough.

[Morbid Angel]

Well you can map it as stepped gradient like so...

[snowballvfx]

Yes, but let's say, for the sake of argument, that I want to blur it even more. Using the falloff I would create more diagonal lines between the "steps". This would indeed broaden the shadow line, but it will do it in such a way that will show that it is a 3D model. I will basically start getting standard 3D shading on the surface.
On the other hand, if I would do it in photoshop, for example, I would get soft shadows that don't conform the 3D model and it will still look flat. This is basically what I'm trying to achieve.

[Neilg]

How come you cant use post? fusion is free and could process this in no time at all.
You're trying to detach something from the 3d model, process in screen space and comp it back onto the image. max doesnt have that kind of control. Even 3d software that did would only have it by using a built in compositor.

[snowballvfx]

I can use post and do. It's just that I'm trying to cut down time spent on producing renders for the client. I wouldn't mind going through Fusion for a few renders here and there, but for the dozens of assets that will need to be rendered, I would rather find a solution that is more direct.

I was hoping that I could cut Fusion from the equation by using some post-effect that I was just not aware of, but I guess there's no way around it unfortunately.