9 Dec 2020 16:12

Static lighting experiments

Last week, following some lighting issues with the Cozy Living Room, we built this basic room to better understand lighting fundamentals in Unreal Engine 4.25. In this example, the scene has 100% static lighting and mesh actors. Nothing moves. This means Unreal Engine can "bake" the lighting and shadows during the build process. If the lights and objects don't move, then the shadows don't move. Actors are not able to move or change conditions at runtime. This then allows UE4 to go further and render some incredible ambient occlusion, light bounces, and colour bleeds.

Notice the red and green tones on the white walls and floor? These colours are the result of the light bouncing off the coloured objects.


Adding motion

To test if these lighting qualities were available with moving elements, a Physical Material was added to the red sphere, turning it into a bouncing ball. This required switching its mode to Moveable instead of Static which in turn causes the light coming off the Directional Light source to no longer bounce colour from the red material. The shadow detailing is still quite high.

Notice the white walls and floor have a slight green tone (Colour Bleed) from light reflecting off the green cone -- whereas the Red Ball, now moving, no longer contributes a red colour bleed to the floor & walls.