【Unity】【エディタ拡張】RGBAの値をそれぞれ別のテクスチャから参照して一つのテクスチャにまとめる

f:id:halya_11:20180419193532p:plain

複数のテクスチャのチャンネルを取り出して一つのテクスチャに統合するエディタ拡張です。

ソースコード

いきなりですがソースコードです。

using System.Collections.Generic;
using UnityEngine;
using UnityEditor;

public class TextureCombinator : EditorWindow {

    public enum ColorChannel
    {
        Red = 0,
        Green = 1,
        Blue = 2,
        Alpha = 3
    }
    
    private const int TEXTURE_FIELD_SIZE = 64;
    
    private List<Texture2D> _textures;
    private List<ColorChannel> _channels;
    private int _width = 128;
    private int _height = 128;
    
    [MenuItem("Window/Texture Combinator")]
    public static void Open()
    {
        GetWindow<TextureCombinator>("Texture Combinator");
    }

    private void Awake()
    {
        _textures = new List<Texture2D>();
        _channels = new List<ColorChannel>();
        for (int i = 0; i < 4; i++) {
            _textures.Add(Texture2D.blackTexture);
            _channels.Add((ColorChannel)i);
        }
    }

    private void OnGUI()
    {
        // GUIを適当に描画する
        _width = EditorGUILayout.IntField("Width", _width);
        _height = EditorGUILayout.IntField("Height", _height);
        EditorGUILayout.LabelField("Textures");
        using (new EditorGUILayout.HorizontalScope("box")) {
            for (int i = 0; i < 4; i++) {
                using (new EditorGUILayout.VerticalScope()) {
                    EditorGUILayout.LabelField(((ColorChannel)i).ToString() + " is", GUILayout.Width(TEXTURE_FIELD_SIZE));
                    using (new EditorGUILayout.HorizontalScope()) {
                        _channels[i] = (ColorChannel)EditorGUILayout.EnumPopup(_channels[i], GUILayout.Width(TEXTURE_FIELD_SIZE * 0.7f));
                        EditorGUILayout.LabelField("of", GUILayout.Width(TEXTURE_FIELD_SIZE * 0.3f));
                    }
                    _textures[i] = EditorGUILayout.ObjectField(_textures[i], typeof(Texture2D), false, GUILayout.Width(TEXTURE_FIELD_SIZE), GUILayout.Height(TEXTURE_FIELD_SIZE)) as Texture2D;
                }
            }
        }

        if (GUILayout.Button("生成")) {
            // outputテクスチャを作って最終的な色を書き込んでいく
            var output = new Texture2D(_width, _height);
            var dest = output.GetPixels();
            var renderTexture = RenderTexture.GetTemporary(_width, _height);
            for (int i = 0; i < 4; i++) {
                // sourceテクスチャの情報をdestに移していく
                // サイズを合わせるために一度renderTextureへの書き込みを挟む
                var source = _textures[i];
                Graphics.Blit(_textures[i], renderTexture);
                var pixels = GetPixelsFromRT(renderTexture);
                for (int j = 0; j < pixels.Length; j++) {
                    dest[j][i] = pixels[j][(int)_channels[i]];
                }
            }
            RenderTexture.ReleaseTemporary(renderTexture);
            output.SetPixels(dest);
            output.Apply();

            // 出来たテクスチャを保存する
            var filePath = EditorUtility.SaveFilePanel("Save Texture", "Assets", "name", "png");
            if (!string.IsNullOrEmpty(filePath)) {
                SaveTexture(filePath, output);
            }
        }
    }

    /// <summary>
    /// テクスチャを保存する
    /// </summary>
    private void SaveTexture(string filePath, Texture2D texture)
    {
        var bytes = texture.EncodeToPNG();
        System.IO.File.WriteAllBytes(filePath, bytes);
        AssetDatabase.Refresh();
    }

    /// <summary>
    /// RenderTextureからピクセル情報を取得する
    /// </summary>
    private Color[] GetPixelsFromRT(RenderTexture target)
    {
        var preRT = RenderTexture.active;
        RenderTexture.active = target;
        
        // ReadPixels()でレンダーターゲットからテクスチャ情報を生成する
        var texture = new Texture2D(target.width, target.height);
        texture.ReadPixels(new Rect(0, 0, target.width, target.height), 0, 0);
        texture.Apply();
        
        RenderTexture.active = preRT;
        return texture.GetPixels();
    }
}