Charles MacDonald's WIP Update!

[Alpha]

News (6/14)

 

Racin' Force I've been running some tests on Racin' Force, a Konami System GX game that uses voxels to generate a 3D playfield. It's an interesting combination of new and old hardware, the PSAC2 chip from earlier games generates a 2D ROZ layer which selects data from a color map and height map. This is used by the PSAC4 chip to render voxels to a framebuffer. An additional list of per-scanline camera data is provided as the PSAC4 knows nothing about the rotation parameters the PSAC2 applied to the color map and height map. Priority is specified for each voxel drawn so sprites can move in front of and behind specific parts of the landscape.

 

A limitation of this setup is that dropped pixels in the PSAC2 output result in missing voxel columns which makes landscape structures look flickery. However at 60 frames per second the results are extremely impressive. Consider how few custom ICs were needed to do this compared to the 3D hardware some arcade games used in 1993. For games with simple terrain such as Racin' Force and Konami's Open Golf Championship, the decision to use voxel graphics was well suited to their graphical needs and a cost-effective choice.

 

I made a low-quality video of the game in action. No controls are wired up, so the car is out of control after the attract sequence.

• Racin' Force footage
  

Of particular interest are the sloped curves on the racetrack, and the tunnel which has both a floor and ceiling made out of voxels. The PSAC4 chip has a lot of different drawing settings which have to get figured out. I've documented the PSAC2 registers and will tackle the PSAC4 next.

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