通过添加透明像素调整精灵的大小

Question

我希望这样做的原因是 Unity 有一个很好的 DTX5 格式，可以大大减少文件大小。但要做到这一点，我需要一个精灵的大小——高度和宽度——都是 4 的倍数。所以我想我创建一个具有所需大小的新纹理，用原始像素加载它的像素并从中制作一个精灵，我将其保存为 asset。问题是，虽然保存 texture 有效，但我得到了具有适当尺寸的相同纹理，保存 sprite 不起作用。它会吐出一些东西，但这还远不符合我的需要。

代码如下：

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

public class ResizeSprites
{
    public void Resize(Sprite sprite)
    {
        int _hei, _wid;
        //getting the closest higher values that are a multiple of 4. 
        for (_hei = sprite.texture.height; _hei % 4 != 0; _hei++) ;
        for (_wid = sprite.texture.width; _wid % 4 != 0; _wid++) ;
        //creating the new texture. 
        Texture2D tex = new Texture2D(_wid, _hei,TextureFormat.RGBA32,false);
        //tex.alphaIsTransparency = true;
        //tex.EncodeToPNG();

       //giving the new texture the "improper" ratio sprite texture's pixel info
        //pixel by pixel.
        for (int wid = 0; wid < sprite.texture.width; wid++)
        {
            for (int hei = 0; hei < sprite.texture.height; hei++)
            {
                tex.SetPixel(wid, hei, sprite.texture.GetPixel(wid, hei));
            }
        }
        //saving the asset. the save works, was used for both meshes as well as textures. 
        Sprite n_spr = Sprite.Create(tex,
            new Rect(0, 0, tex.width, tex.height),
            new Vector2(0.5f, 0.5f), 100.0f);
        AssetSaver.CreateAsset(n_spr, sprite.name + "_dtx5");
    }

}

这是我的结果：

第一个是原图，第二个是给我的。

编辑： 即使我不保存我的创作，只是将它实例化为一个GameObject，结果还是一样丑。

Answer 1

你真的不需要所有这些代码。Texture2D 有一个调整大小的函数，所以只需从 Sprite 中拉出 Texture2D 然后调用 re-szie 函数来调整它的大小。就是这样。

像这样：

public void Resize(Sprite sprite)
{
    Texture2D tex = sprite.texture;

    tex.Resize(100, 100, TextureFormat.RGBA32, false);

    Sprite n_spr = Sprite.Create(tex,
        new Rect(0, 0, tex.width, tex.height),
        new Vector2(0.5f, 0.5f), 100.0f);

    AssetSaver.CreateAsset(n_spr, sprite.name + "_dtx5");
}

至于你原来的问题，那是因为你没有调用Apply function. Each time you modify the pixels, you are supposed to call the Apply函数。最后，始终使用 GetPixels32 而不是 GetPixel 或 GetPixels。原因是因为 GetPixels32 比函数的其余部分快得多。

public void Resize(Sprite sprite)
{
    int _hei, _wid;
    //getting the closest higher values that are a multiple of 4. 
    for (_hei = sprite.texture.height; _hei % 4 != 0; _hei++) ;
    for (_wid = sprite.texture.width; _wid % 4 != 0; _wid++) ;
    //creating the new texture. 
    Texture2D tex = new Texture2D(_wid, _hei, TextureFormat.RGBA32, false);
    //tex.alphaIsTransparency = true;
    //tex.EncodeToPNG();

    //giving the new texture the "improper" ratio sprite texture's pixel info
    //pixel by pixel.

    Color32[] color = sprite.texture.GetPixels32();

    tex.SetPixels32(color);

    tex.Apply();

    //saving the asset. the save works, was used for both meshes as well as textures. 
    Sprite n_spr = Sprite.Create(tex,
        new Rect(0, 0, tex.width, tex.height),
        new Vector2(0.5f, 0.5f), 100.0f);
    AssetSaver.CreateAsset(n_spr, sprite.name + "_dtx5");
}

通过添加透明像素调整精灵的大小

Resizing a sprite by adding transparent pixels

c#

textures

sprite

unity3d