I am trying to create a custom property drawer for a type that should be displayed as a 2D image, but when I use EditorGUI.DrawPreviewTexture or GUI.DrawTexture to draw the image, it disappears after a short time, and reappears for a short time when the inspector is updated. How do I properly draw a texture in a PropertyDrawer?
Minimal code:
[CustomPropertyDrawer (typeof (testObj))]
public class testObjDrawer : PropertyDrawer {
int tSize = 128;
Texture2D texture;
public override void OnGUI(Rect pos, SerializedProperty prop, GUIContent label) {
if (texture == null)
InitializeTexture();
EditorGUI.BeginProperty (pos, label, prop);
pos = EditorGUI.PrefixLabel (pos, GUIUtility.GetControlID(FocusType.Passive), label);
EditorGUI.DrawPreviewTexture(pos, texture);
EditorGUI.EndProperty ();
}
private void InitializeTexture() {
texture = new Texture2D(tSize, tSize,TextureFormat.RGB24,false);
//tex = new Texture2D(tSize, tSize);
Color32[] clr = new Color32[tSize * tSize];
for (int i = 0; i < clr.Length; i++)
clr[i] = Color.black;
texture.SetPixels32(clr);
texture.Apply();
}
}
I’m starting to think this is a bug, because it did the same thing when I tried a conversion of the EditorWindow example for EditorGUI.DrawPreviewTexture.
I did find a workaround involving GUIStyle
I found out that the texture doesn’t flicker if the PropertyDrawer is drawn by a custom Editor. If you know where your PropertyDrawer is going to be used, simply make an empty stub deriving from the Editor for that object, like this:
[CustomEditor(typeof(ScriptableObject))]
public class ScriptableObjectInspector : Editor
{
// Empty stub so a custom PropertyDrawer with textures would work.
// (Workaround for Unity bug #514655.)
}
That’s the closest I got to drawing textures with custom texture coordinates (e.g. sprites).
However, remember to put your drawing calls behind:
if (Event.current.type == EventType.Repaint) {
EditorGUI.DrawPreviewTexture(rect, texture);
}
Or you’ll get garbage in the supplied position rectangle. The documentation only mentions it for Graphics.DrawTexture(), but it is also needed in this case.
Two alternatives to DrawPreviewTexture that don’t use GUIStyle and use the ScaleToFit scaling method: scale down the texture keeping the aspect ratio only when position is smaller than the texture rect.
// ScaleToFit method, left-aligned at the position of the prefix label
EditorGUI.LabelField(position, new GUIContent(texture));
// ScaleToFit method, horizontally centered, bottom-aligned, shadow effect
EditorGUI.DropShadowLabel(position, new GUIContent(texture));
I had similar issue but when using EditorGUI.DrawRect(). My workaround is to add this simple line somewhere in your script (like below your PropertyDrawer class):
[CanEditMultipleObjects][CustomEditor(typeof(MonoBehaviour),true)] public class MonoBehaviour_DummyCustomEditor : Editor {}//this line fixes EditorGUI flickering bug
ps: if your class doesn’t inherit from MonoBehaviour then just replace it with that class name (or it’s parent class if you are using inheritance)
This script copies the sprite to a new texture, not optimized but seems to work.
Caveat: The texture must be set as Read/Write Enabled in import settings.
public static class GUIHelper
{
private static GUIStyle s_TempStyle = new GUIStyle();
public static void DrawTexture(Rect position, Texture2D texture)
{
if (Event.current.type != EventType.Repaint)
return;
s_TempStyle.normal.background = texture;
s_TempStyle.Draw(position, GUIContent.none, false, false, false, false);
}
public static void DrawTexture(Rect position, Sprite sprite)
{
if (Event.current.type != EventType.Repaint)
return;
//The texture must be set as Read/Write Enabled in import settings.
Texture2D texture = new Texture2D((int)sprite.rect.width, (int)sprite.rect.height, sprite.texture.format, false);
Color[] pixels = sprite.texture.GetPixels((int)sprite.rect.x, (int)sprite.rect.y, (int)sprite.rect.width, (int)sprite.rect.height);
texture.SetPixels(pixels);
texture.Apply();
s_TempStyle.normal.background = texture;
s_TempStyle.Draw(position, GUIContent.none, false, false, false, false);
}
}
Couldn’t get scriptableobject sprites to draw consistently in a property drawer. The default EditorGUI.ObjectField when large enough to show the icon would randomly flicker the sprite and render it with a delay after clicking in the inspector panel.
Bunch of helpful tips in this thread. In the end I changed the height of the ObjectField so the default icon is not drawn and use a GUIStyle to render the sprite as a background. Using this method I can mash the arrow key down through my scriptableobjects and the sprites show instantly with now weirdness in the inspector.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
[CustomPropertyDrawer(typeof(Sprite))]
public class SpriteDrawer : PropertyDrawer {
private static GUIStyle s_TempStyle = new GUIStyle();
public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
{
var ident = EditorGUI.indentLevel;
EditorGUI.indentLevel = 0;
Rect spriteRect;
//create object field for the sprite
spriteRect = new Rect(position.x, position.y, position.width, EditorGUIUtility.singleLineHeight);
property.objectReferenceValue = EditorGUI.ObjectField(spriteRect, property.name, property.objectReferenceValue, typeof(Sprite), false);
//if this is not a repain or the property is null exit now
if (Event.current.type != EventType.Repaint || property.objectReferenceValue == null)
return;
//draw a sprite
Sprite sp = property.objectReferenceValue as Sprite;
spriteRect.y += EditorGUIUtility.singleLineHeight+4;
spriteRect.width = 64;
spriteRect.height = 64;
s_TempStyle.normal.background = sp.texture;
s_TempStyle.Draw(spriteRect, GUIContent.none, false, false, false, false);
EditorGUI.indentLevel = ident;
}
public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
{
return base.GetPropertyHeight(property, label) + 70f;
}
}