After a long pause, I decided to give distance fields a try. Here's result:

This is a CSG-based shape. Sphere minus torus minus cube. Positions of the primitives are hardcoded.

Here's the code:

DistanceFields.shader:

Shader "Unlit/RaycastDistanceFields"{
    Properties  {
        _MainTex ("Texture", 2D) = "white" {}
        _Color ("Color", Color) = (1, 1, 1 …

This is a basic update of previous example.

It is largely the same thing as before:

However, I cleaned up the code.

Basically, I'm thinking about moving from mathematically defined primitives (meaning every figure is defined by a formula) to distant fields which have somewhat simpler definition..

Distant field, basically …

Alright. I expected this to take less time, but things happened.

Here's what I have right now.

Point liights,

spot lights,

and directional lights

are supported and cast shadows.

Getting there, however, was unexpectedly difficult.

Here's the code. It is in need of some refactoring, but it works.

RaycastObject.shader …

I originally planned to finish and post this on monday. But stuff happened. So here we go.

Here's what I got at the moment:

Good news: I got point and spot lights working. Raytraced sphere receives shadows from external sources. Oh, right, cookies and attenuation now works as well.
Bad …

So. Here's what I got at the moment:

It is the next iteration of shader from before. Here's the mesh geometry of this object:

So, good news:

I got lighting. Attenuation isn't suported (yet), but it interacts with unity's point and directional lights, reads their colors, and also grabs ambient …

Alright, quick question. How many triangles are in this sphere?:

The answer is 12.

The sphere is a raytraced primitive, which is actually a box (boundaries of the box are indicated by green wireframe). That's why it has 12 triangles.

Unity 3d shader system, despite having numerous flaws, allows easy …