Hardware Heritage
Voxel Space is a rendering technique that simulates terrain by ray-casting through a 2D heightmap. Popularized by the game Comanche: Maximum Overkill, it bypassed the polygon-count limits of early 90s hardware to deliver massive, organic-looking landscapes that were truly revolutionary at the time.
PC Supremacy
Voxel Space was the PC's answer to the Amiga's custom hardware. It required pure CPU speed to iterate through heightmaps. On a 486, it allowed for huge organic landscapes that were impossible with polygons at the time.
Amiga Bottleneck
Amiga versions of voxel engines were rare and slow. The 68000 lacked the raw calculation speed for the many divisions required per-column, and the bitplane display made vertical line drawing very expensive.
Modern Logic
The engine uses ray-marching in the fragment shader to simulate the column-based approach, utilizing the GPU's texture sampling to fetch height data in parallel.
Voxel Space
Simulating infinite terrain through scanline raycasting.
Legacy C (Software)
for (z = 1; z < MAX_DIST; z += 1) {
// Height lookup and projection
h = heightMap[camX + dx*z][camY + dy*z];
screenY = (camHeight - h) / z * scale + horizon;
// Draw only visible vertical spans
if (screenY < yBuffer[x]) {
DrawVerticalLine(x, screenY, yBuffer[x], color);
yBuffer[x] = screenY;
}
}
Modern GLSL
for(float d=1.0; d < 20.0; d += 0.4) {
vec2 p = cameraPos + rayDir * d;
float h = get_height(p);
float projH = (camHeight - h) / d;
if(h > uv.y * d) {
color = terrain_color(p, d);
break;
}
}