UnityEditor - Drawing on a Texture

Questions & Answers
1

hello, do you know how I can draw with my mouse on textures? or other drawing tricks? I speak in from the side of the editor not in the gameScene. Below a sample code: 

using UnityEngine;
using UnityEditor;

public class MyWindow : EditorWindow
{
   string myString = "Bella zi";
   bool groupEnabled;
   bool myBool = true;
   float myFloat = 1.23f;
   Texture2D texty = new Texture2D(150,150);

   // Add menu named "My Window" to the Window menu
   [MenuItem ("Window/My Window")]
   static void Init ()
   {
      // Get existing open window or if none, make a new one:
      MyWindow window = (MyWindow)EditorWindow.GetWindow (typeof (MyWindow));
      window.Show ();
   }

   void OnGUI ()
   {
      GUILayout.Label ("Base Settings", EditorStyles.boldLabel);
      EditorGUILayout.TextArea(myString, GUILayout.Height(200));

      //little box with texture to draw <-------
      GUILayout.Box(texty,GUILayout.Width(150),GUILayout.Height(150));      

      groupEnabled = EditorGUILayout.BeginToggleGroup ("Optional Settings", groupEnabled);
      myBool = EditorGUILayout.Toggle ("Toggle", myBool);
      myFloat = EditorGUILayout.Slider ("Slider", myFloat, -3, 3);
      EditorGUILayout.EndToggleGroup ();
   }
}

thanks!!

2

You can use Texture2D.SetPixel(...) to set the color of an individual pixel on a texture. If your texture is on the GUI, it should be fairly easy to compute its position using its rectangle, which you can then offset from the Mouse position in order to get the pixel coordinates of the pixel that the mouse is over.

If this texture is in 3D space, however, you can check out my other answer here:

http://answers.unity3d.com/questions/10683/detecting-mouseclick-on-pixels-in-sprite-using-sm2-pixel-collisions

which details how you can Raycast to get which pixel the mouse is pointing at.