Unity 3D Compact GUI Attribute for Vectors and Quaternions.

CompactGuiAttribute.cs

using UnityEngine;

public class CompactGuiAttribute : PropertyAttribute {}

CompactGuiDrawer.cs

using UnityEngine;
using UnityEditor;

[CustomPropertyDrawer (typeof(CompactGuiAttribute))]
public class CompactGuiDrawer : PropertyDrawer
{
  const float ShrinkLabelAmount = 20f;

  public override void OnGUI (Rect position, SerializedProperty property, GUIContent label)
  {
    float labelWidthCache = EditorGUIUtility.labelWidth;
    bool wideModeCache = EditorGUIUtility.wideMode;

    EditorGUIUtility.labelWidth -= ShrinkLabelAmount;
    EditorGUIUtility.wideMode = true;

    EditorGUI.PropertyField (position, property, label);

    EditorGUIUtility.wideMode = wideModeCache;
    EditorGUIUtility.labelWidth = labelWidthCache;
  }
}

USAGE:

• CompactGuiAttribute.cs: Save to any non-editor folder or subfolder (e.g. Scripts/)

• CompactGuiDrawer.cs: Save to editor folder or subfolder (e.g. Scripts/Editor/)

• For any Unity Vector* or Quaternion property, precede with the attribute [CompactGui] as such:

public class MyObject : MonoBehavior {
  [CompactGui]
   public Vector3 positionVector;
}

COMPATIBILITY

• Should work with any Unity 5.x
• Tested and built with Unity 5.5.1