a 4k exe-gfx released at Revision 2021



I found yet another interesting way to render placeholder geometry :D

With this entry, I tried to recreate the look of a point cloud visualization, where there is one scanner in the middle of the scene that samples points outward and the camera is viewing the collected data from the outside.

To create a sense of depth, the points are colored according to how close to the scanner they are, and they are rendered with lots of depth of field.

The Renderer

The image is rendered by accumulating many samples per pixel over time, using the Blossom framework developed by yx. Each sample is computed in two steps.

In the first step, it initializes a ray marcher with a random t value and then marches forward to the surface of the SDF. This is done so we uniformly sample the space around the scanner and don't get stuck near the camera. The marching loop only does 6 iterations.

In the second step, we check if the "scanner" at the origin can see the computed intersection point by ray marching towards the origin. To make the geometry look like it is made out of particles rather than large solid shapes, the surfaces are colored according to a high-frequency dot texture.

The Scene

The scene itself is incredibly simple. For those who speak shader, this is the entire SDF.

float map(vec3 p) {
    vec3 q = abs(fract(p)-.5);
    q = max(q, q.zxy);
    return min(min(q.x, q.y), q.z) - 0.14;

If you position the camera at the origin, it looks like this.



The entry ended up in 17th place in the compo. To be fair, it was an incredibly strong year, the exe-gfx compo didn't even have 17 entries the year before.

I also think the entry works best on a large screen where you can see all the little details, which is normally perfect for demoparties, but this was released during the period when all parties were online only, so people most likely saw it on a small screen with stream compression.

I'm still very happy with the final result and a slightly altered version of it is still my desktop wallpaper two years later.