• LockedOn

Catalyst Wake - Update 12




Hello again! This past week I modeled seven new characters and completed two backgrounds — which is definitely enough to create the next few scenes I need.


I figured this update needed a bit more substance, so I'm going to explain a little of what I know about lighting scenes. I'm no expert, but maybe someone will find this useful?


The software I use is Cheetah3D — you've probably seen me mention that before. But what I'm going to discuss will be true in basically every 3d program.


So, most unlit scenes look like this when rendered:


Technically, this is lit — the light is the default camera light. Obviously, if it was completely unlit it would be dark. But I call it "unlit" for simplicity's sake. It's very useful when you're creating the scene, to see all the textures and shapes of the objects clearly. I use it for renders where I need to trace the 3d models. But obviously, this would never do for a final rendered scene.


If you add a simple directional light, this happens:





This light does not have any soft shadows. It's fairly unrealistic, and I've moved away from using it over time. However, sometimes you do need it for outdoor scenes.


A simple light like this is a good way to illustrate what bounced lighting does to your scene:





As you can see, the light has bounced from the plane to the bottom of the ball, which mimics what light does in real life. In Cheetah3D, I use a Radiosity tag on the camera to achieve this. Sometimes, it can screw up the scene a bit with odd blotchy dots. This happens in very complicated areas or when there aren't enough samples:



Sometimes I've had to leave Radiosity out just to avoid this. But the good news is that sometimes you don't need Radiosity and the scene looks the same with or without it. That tends to be the case in scenes with low lighting or darker colors that wouldn't bounce.


As I mentioned, I don't use directional lights much anymore. Instead, I use point lights:

In order to achieve soft shadows with a point light, I increase its radius and the amount of samples.




You'll notice there's a bit of a problem here. A point light isn't a great substitute for a directional light because, well, everything's emanating from one point. If I had an outdoor scene, it wouldn't be lighting the entire environment, and everything would look darker as it got further away from the light — which doesn't happen with the sun. The solution is to increase the attenuation (I'm not quite sure other 3D programs do it this way, but this is how Cheetah3D does it).

This is basically like increasing the distance the light travels.


Now I want to stop for moment to talk about samples. If you reduce the number of samples, you get this really cool effect:

It reminds me of pointillism. Even though it's technically "wrong" and you normally would increase the samples so that you don't see this, I like the look of it a lot. I used it in Little Yaga to give the scenes a textured, storybook appearance. Look what happens when you combine it with a Toon shader:

It kind of looks like an illustration! Anyway, that's just a fun thing I like to do.


Once I increase the light intensity to match how bright the directional light was, it looks like this:

And that's pretty much my set-up for outdoor lighting! I guess that's what this little tutorial was about all along! Other than this, I try to include emissive properties in my props, if I'm using Radiosity. That's light information that comes from a texture, rather than a Light source. You can see the effect here:

What's great is that it can be in any shape and is a really organic way to light stuff. But like I said, it requires Radiosity, which isn't always the best option.


This was just a short overview of how I set up lights. Obviously, it's an extremely deep topic. But if you were wondering how I personally do it — well, there you go!


We're in the second half of the month now, and I want to make sure I end the month with as many CGs in the bag for Summit as possible. So I'll be trying to make 14 CGs every day until the end of the month. My next update will be on May 1st, letting you know how that went!


Until then!


— LockedOn.

128 views0 comments

Recent Posts

See All