Unit 72: CGI Rendering and Lighting for Computer Games Animation

This unit tasked us with creating a high detail lighting scene for Unreal Engine with a theme that links into our umbrella project.

I wanted to have a kind of dark dungeon prison scene with a focal point of light shafts coming through a grate in the roof of the area.

Sunshaft Effects

A main part of the scene is the sunshafts coming into the room from the ceiling. I soon discovered that in the current version of Unreal, the built-in sunshaft effect was not as advanced as I'd hoped, and can only be seen from certain angles.

I had to create my own custom sunshaft effect, which simulates the effect I wished to have in my scene.

It is a kind of streaky, semi-transparent texture placed on flat polygon planes, which allows the effect to be seen from any angle.

Animated Lighting

Because I wanted the scene to seem more alive, and not just static, I created some lighting objects in blueprint with animated light sources.

To get these effects, I created both a torch and a candle with lighting components inside.

The lighting components were controlled by blueprint scripts with random numbers with in a certain range used to move the light around to make the shadows move, and also to control the brightness of the light to add to the flickering fire effect.

Lighting Material Function

Using an online tutorial video, I created an animated lighting material function to give the effect of bouncing light from water onto surfaces in the scene.

The lighting function uses mainly a sine wave generator converted to colours to make the wave effects with some noise textures animated in various directions to give a warped effect to the sine wave, representing dirt and other stuff breaking up the surface of the water, affecting the reflected light.

Wet Cobbles

Starting with some research on the Unreal Reflections demo, I was really drawn to the water effect on the floor, and wanted something the same in my scene, but over the cobble stones.

I first converted the original cobblestone material into a Material Function, so that it would be compatible with the water effect.

I then created the water effect material using the Reflections demo material as a guide, then fed the new cobbles Material Function into where the original floor material would have been used.

The way the material is set up, it uses the blue value of Vertex Painting on the object it is applied on to control how much water effect comes through and at what strength, as shown in the example below:

Blue removes the water effect entirely, and differing levels of blue control how wet the surface appears, from slightly damp all the way up to full puddle.

To vertex paint the whole floor, I hid most of the objects in the scene, leaving only the floor and the walls, to give me an idea where to paint and concentrate.

The vertex painter does NOT support tablet preassure, so I had to use a low flow setting on the vertex brush and gradually build up the effect using multiple passes with the mouse.

And here's a look at how it appears in engine.

Camera and Sequencer

To make an animated video sequence for this unit, I learned how to use the animation sequencer in Unreal.

The sequencer interface is very similar to the one used in Maya, which I have already used before.

It uses key-frames and animation graphs and curves in the exact same way as Maya does.

I used the key-framing to animate a CineCamera object around the scene.

The graph and curve editor came in useful when shots weren't to my liking so I could adjust how the movement smoothed.

The first time I rendered the sequence I found there were some graphical glitches and drop-out when objects moved quickly past the camera.

I did some research on the issue and found it to be caused by a setting meant to speed up performance when in-game by hiding objects which are out of view. By turning off Occlusion Culling I got rid of these issues.