A Wolfenstein 3D style raycasting engine, written entirely in LabVIEW FPGA.
Note that the LabVIEW FPGA module or FPGA hardware isn't a requirement - the same code will run on PC using LabVIEW, including LabVIEW Community edition.
Click the image below to see a short video of it in action.
- Runs entirely from cRIO-9041 FPGA (a Xilinx Kintex-7 7K70T), no RT required
- Also runs on PC without code changes
- 800x600@60Hz video
- 2-bit R-2R circuit provides VGA signal
- 400x300 internal render resolution, pixel doubled
- Double buffered video
- 64 color palette on FPGA, 256 colors on desktop (via intensity graph)
- Parallelized column renderer
- 30 fps on FPGA, 60 fps on PC
- 60 fps on FPGA with 4x parallelization and no sprites (frees up DSP space needed)
- Includes FizzleFade!
A simple circuit was created as a video adapter from the 5V TTL module.
There's two bits per color component, each converted to the required 0.7Vpp VGA levels using an R-2R circuit. Signals and schematic are below.
| Signal | NI-9401 Pin | Resistor | VGA Pin |
|---|---|---|---|
| DO0 (Red LSB) | 14 | 750 | 1 |
| COM | 3 | 100 | 1 |
| DO1 (Red MSB) | 16 | 390 | 1 |
| DO2 (Green LSB) | 17 | 750 | 2 |
| COM | 6 | 100 | 2 |
| DO3 (Green MSB) | 19 | 390 | 2 |
| DO4 (Blue LSB) | 20 | 750 | 3 |
| COM | 9 | 100 | 3 |
| DO5 (Blue MSB) | 22 | 390 | 3 |
| DO6 (H_Sync) | 23 | - | 13 |
| DO7 (V_Sync) | 25 | - | 14 |
| COM (GND) | 10 | - | 5 |
| COM (Sync GND) | 10 | - | 10 |
| COM (Red GND) | 1 | - | 6 |
| COM (Green GND) | 1 | - | 7 |
| COM (Blue GND) | 1 | - | 8 |
The two bits per color allow for up to 64 colors in total. The image below shows a side-by-side of a 64 color image, and the resulting output from the video adapter. The colors aren't great compared to the source image, but for a couple of dollars' worth of video adapter, they aren't bad.
This project includes modified graphics and maps from shareware version of Wolfenstein 3D. Copyright (c) id Software
Includes h_sync and v_sync functions from Tetris On FPGA, used under the MIT license. Copyright (c) 2019 VI Technologies
Portions of this code adapted from examples found in Game Engine Black Book: Wolfenstein 3D by Fabien Sanglard.
Portions of this code adapted from examples provided in the series of raycasting articles by Lode Vandevenne.