The aim of this demo was to show how the Vector Units of the PS2 can be used to create various animated lighting effects, and to investigate methods for creating reflections. Working on top of a framework which was provided for this piece of coursework, I implemented a hierarchical system for managing entities in the scene, as well as producing a range of effects.
Effects
- Animated Point Lights – 4 animated point lights were featured in the scene, rapidly changing colour, size and position to give a flickering effect. The intensity of these faded over distance squared, acting only on a small area.
- Ambient and Directional Lights – ambient and directional lighting was also implemented on the Vector Unit, using the normal for exch vertex to calculate intensity.
- Reflection – a range of techniques were investigated for creating the reflected floor of the cathedral, including using the Scissor Buffer of the PS2, and creating a stencil by rendering the floor geometry to the alpha bits of the framebuffer.
- Texture and Alpha Blending – using multiple layers of geometry in close proximity allowed for textures to be blended, improving the flame effect from each lamp. Various alpha blending algorithms were also used to alter the values of colours seen through “transparent” shapes, such as the stained glass window.
Controls
The Cathedral demo can only be played using a Playstation 2 Linux kit. The camera can be moved using both analogue joysticks.
Files
- Read the VCL Code online.
- Download the source code.
- The executable for the Cathedral demo.
- The executable for an experiment with the scissor buffer (use ‘X’ to switch camera).