Tag Archives: raycasting

7dfps

7dfps 2013 : Writing a raycaster

When the first 7 day FPS challenge was launched in 2012, I remember wishing I could participate but knowing full well that I didn’t have the skill to make anything of it. I’d never done any serious 3d programming and had no experience with the asset pipeline required for a 3d project. I decided I’d learn how to use a simple 3D engine in my free time over the following year and participate next time.

Well, it’s one year later, 7DFPS is back in business, and I still have no experience in any of the above areas. I had already resigned myself to missing out again, but I happened to stumble across this article on writing a “pseudo-3d” engine such as is used in Id Software’s early games, including Doom. I decided to give it a shot. Here’s my progress for the first two days.

1

The first step is figuring out where the walls are. The above screenshot shows that not happening.

 

2

A bit of an improvement.

 

yays

Wall segments are being drawn, but in completely the wrong places.

 

omgyays

Segments are now positioned correctly. I changed the texture to a standard pink/black checkerboard for debugging, but it isn’t showing up right. In addition, the perspective is “fisheyed”, causing curved lines at the periphery of the field of view.

 

nofish

Better.

 

perfect

The elusive “perfectly textured wall” in its native environment.

 

sexyhotness

Some awesome modern art I created while trying to fix textures.

 

textures

The final result as of this writing. At this point the engine is basically done and I can get to work on some gameplay.