Question by sjQrs · Sep 14, 2020 at 11:16 AM · raycast texture2d setpixel

drawing on texture during runtime

i am working on script that is supposed to draw on object with the use of raycasting it has to work kinda like a marker would. But i have serveral issues. 1st issue : it does not draw smoothly(like demonstrated in the picture below) 2nd issue: when i draw on one object the other object with the same texture get drawn on as well.

my code:

 private int Size = 10;
 public GameObject marker;

 void Update()
 {
    
     Vector3 markerRange = transform.TransformDirection(Vector3.forward) ;
     RaycastHit hit;

     //draws pixels on texture with mesh collider

     if (Physics.Raycast(transform.position, markerRange ,out hit, 0.1f))
     {
         Renderer rend = hit.transform.GetComponent<Renderer>();
         MeshCollider meshCollider = hit.collider as MeshCollider;

         Texture2D tex = rend.material.mainTexture as Texture2D;
         Vector2 pixelUV = hit.textureCoord;
         pixelUV.x *= tex.width;
         pixelUV.y *= tex.height;

         //multiplies pixelsize by 10

         for (int i = 0; i < Size; i++)
         {
             int x = (int)pixelUV.x;
             int y = (int)pixelUV.y;

             
              y += i;
              x += i;

             //Apply
             tex.SetPixel(x, y, Color.red);

         }
         tex.Apply();
     }
     //shows range for marker
     Debug.DrawRay(transform.position, markerRange, Color.blue);
 }

picture of result of current code alt text