图集打包Atlas
制作
NGUI是必须先打出图集然后才能开始做界面。因为始终都要去考虑你的UI图集。比如图集会不会超1024 ,图集该如何来规划等等。
UGUI 让开发者彻底模糊图集的概念,让开发者不要去关心自己的图集。做界面的时候只用小图,而在最终打包的时候unity才会把你的小图和并在一张大的图集里面。然而这一切都是自动完成的,开发者不需要去care它。
NGUI在打包图集的时候图集的默认格式是RGBA32,也就是支持带透明通道的图片,这样一张1024的图集也就是4M内存。为了优化图集,我们可以选择把带透明通道图片 和 不带透明通道的图片分开打图集,这样可以减少内存的占用量。然而着一切的一切在NGUI上都需要手动操作,而SpritePacker则全自动完成。Sprite上的Packing Tag 同一标识的图片。
UGUI会把相同图片格式的图片打包成同一图集。MomoAtals和RUORUOAtlas就是Packing Tag的标识符,那么此时根据这两个标识符SpritePacker将打出两个图集出来。 因为MomoAtlas这些图片中,一部分是RGBA32格式,还有一部分是ETC 4bits格式,那么MomoAtlas将被在分成两个图集,就是尾缀带Group的。
打包Sprite Packer有两个打包模式
DefaultPackerPolicy:是默认的打包方式,也是矩形打包方式。他会把所有的小图按照矩形的方式来排列,如果宽高不一样的图片,它们会自动补起。
TightPackerPolicy:是紧密打包方式,也就是尽可能的把图片都打包在图集上,这种方式要比DefaultPackerPolicy打包的图片更多一些,也就是更省空间。
图中[TIGHT]开头的就表示单独这张图采用TightPackerPolicy打包模式。
自定义打包
假如我想自定义打包方式咋办?比如我想设置图片打包格式,或者图集大小等等怎么办?把如下代码放在Editor文件夹下, 在代码里面就可以设置图集的属性了。
using System;
using System.Linq;
using UnityEngine;
using UnityEditor;
using UnityEditor.Sprites;
using System.Collections.Generic;
// DefaultPackerPolicy will pack rectangles no matter what Sprite mesh type is unless their packing tag contains "[TIGHT]".
class DefaultPackerPolicySample : UnityEditor.Sprites.IPackerPolicy
{
protected class Entry
{
public Sprite sprite;
public AtlasSettings settings;
public string atlasName;
public SpritePackingMode packingMode;
}
public virtual int GetVersion() { return 1; }
protected virtual string TagPrefix { get { return "[TIGHT]"; } }
protected virtual bool AllowTightWhenTagged { get { return true; } }
public void OnGroupAtlases(BuildTarget target, PackerJob job, int[] textureImporterInstanceIDs)
{
List
foreach (int instanceID in textureImporterInstanceIDs)
{
TextureImporter ti = EditorUtility.InstanceIDToObject(instanceID) as TextureImporter;
TextureImportInstructions ins = new TextureImportInstructions();
ti.ReadTextureImportInstructions(ins, target);
TextureImporterSettings tis = new TextureImporterSettings();
ti.ReadTextureSettings(tis);
Sprite[] sprites = AssetDatabase.LoadAllAssetRepresentationsAtPath(ti.assetPath).Select(x => x as Sprite).Where(x => x != null).ToArray();
foreach (Sprite sprite in sprites)
{
//在这里设置每个图集的参数
Entry entry = new Entry();
entry.sprite = sprite;
entry.settings.format = ins.desiredFormat;
entry.settings.usageMode = ins.usageMode;
entry.settings.colorSpace = ins.colorSpace;
entry.settings.compressionQuality = ins.compressionQuality;
entry.settings.filterMode = Enum.IsDefined(typeof(FilterMode), ti.filterMode) ? ti.filterMode : FilterMode.Bilinear;
entry.settings.maxWidth = 1024;
entry.settings.maxHeight = 1024;
entry.atlasName = ParseAtlasName(ti.spritePackingTag);
entry.packingMode = GetPackingMode(ti.spritePackingTag, tis.spriteMeshType);
entries.Add(entry);
}
Resources.UnloadAsset(ti);
}
// First split sprites into groups based on atlas name
var atlasGroups =
from e in entries
group e by e.atlasName;
foreach (var atlasGroup in atlasGroups)
{
int page = 0;
// Then split those groups into smaller groups based on texture settings
var settingsGroups =
from t in atlasGroup
group t by t.settings;
foreach (var settingsGroup in settingsGroups)
{
string atlasName = atlasGroup.Key;
if (settingsGroups.Count() > 1)
atlasName += string.Format(" (Group {0})", page);
job.AddAtlas(atlasName, settingsGroup.Key);
foreach (Entry entry in settingsGroup)
{
job.AssignToAtlas(atlasName, entry.sprite, entry.packingMode, SpritePackingRotation.None);
}
++page;
}
}
}
protected bool IsTagPrefixed(string packingTag)
{
packingTag = packingTag.Trim();
if (packingTag.Length < TagPrefix.Length)
return false;
return (packingTag.Substring(0, TagPrefix.Length) == TagPrefix);
}
private string ParseAtlasName(string packingTag)
{
string name = packingTag.Trim();
if (IsTagPrefixed(name))
name = name.Substring(TagPrefix.Length).Trim();
return (name.Length == 0) ? "(unnamed)" : name;
}
private SpritePackingMode GetPackingMode(string packingTag, SpriteMeshType meshType)
{
if (meshType == SpriteMeshType.Tight)
if (IsTagPrefixed(packingTag) == AllowTightWhenTagged)
return SpritePackingMode.Tight;
return SpritePackingMode.Rectangle;
}
}
虽然可以全选在设置图片的pack tag,但是我觉得最好全自动完成,比如我们把图片放在不同的文件夹下,那么文件夹的名子就可以用做Atals的名子。最后在分享一条这样的脚本。
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using UnityEngine; using System.Collections; using UnityEditor; using System.IO;
public class Post : AssetPostprocessor {
void OnPostprocessTexture (Texture2D texture) { string AtlasName = new DirectoryInfo(Path.GetDirectoryName(assetPath)).Name; TextureImporter textureImporter = assetImporter as TextureImporter; textureImporter.textureType = TextureImporterType.Sprite; textureImporter.spritePackingTag = AtlasName; textureImporter.mipmapEnabled = false; }
} |