Using functions from the c# script inside the shader

Question

I'm trying to write a fragment shader that will give a different color depending on the position. For this purpose, I wrote a script that returns the color from given vector3 and I want to call this function inside a shader. Is it possible at all?

My code:

    using System.Collections.Generic;
    using UnityEngine;

    public class CustomLight : MonoBehaviour
    {
      public static List<CustomLight> lights = new List<CustomLight>();

     [Min(0)]
     public float intensity = 1;
        public Color color = Color.white;
        [Min(0)]
        public float radius = 4;
        [Range(0, 1)]
        public float innerRadius = 0;

        public Color GetLight(Vector3 point)
        {
            if (intensity <= 0 || radius <= 0) return Color.clear;

            float value = 0;
            float distanceSqr = (point - transform.position).sqrMagnitude;
            if (distanceSqr >= radius * radius) return Color.clear;

            if (innerRadius == 1) value = 1;
            else
            {
                if (distanceSqr <= radius * radius * innerRadius * innerRadius) value = 1;
                else value = Mathf.InverseLerp(radius, radius * innerRadius, Mathf.Sqrt(distanceSqr));
            }

          return color * intensity * value;
       }

       private void OnEnable()
       {
           if (!lights.Contains(this)) lights.Add(this);
       }
        private void OnDisable()
       {
           lights.Remove(this);
       }
    }

I haven't written any shader yet, because I don't even know where to start. I need the sum of results from all scripts on the scene, then multiply it by the color of the shader.

I apologize for poor English

Yes, it is possible. Could you share some of your code?

KBaker
– KBaker

2020-05-16 23:31:34 +00:00
Commented May 16, 2020 at 23:31 — KBaker
– KBaker, Commented May 16, 2020 at 23:31
@KBaker I edited the post adding code to it.

Max Shein
– Max Shein

2020-05-17 08:17:13 +00:00
Commented May 17, 2020 at 8:17 — Max Shein
– Max Shein, Commented May 17, 2020 at 8:17

Zami · Accepted Answer · 2020-05-17 09:04:42Z

2

C# functions run on the CPU while shaders run on the GPU, as such you can't call c# functions from a shader.

You can however access variables passed to the shaders through the materials via Material.SetX methods, which is likely the closest to what your trying to achieve.

answered May 17, 2020 at 9:04

Zami

1135 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Using functions from the c# script inside the shader

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related