从远程图像编辑立方体贴图天空盒

Question

我需要从服务器下载一个图像，然后在立方体图中转换它，最后把这个立方体地图放在我的天空盒中。

我使用 C#。

我想出了这个代码：

public string url = "image/url.jpg";
void Update() {
// When trigger, we start the process
if (Input.GetKeyDown("f")) {
// start Coroutine to handle the WWW asynchronous process
StartCoroutine("setImage");
}
}
IEnumerator setImage () {
Texture2D tex;
tex = new Texture2D(2048, 2048, TextureFormat.RGBA32, false);
WWW www = new WWW(url);
//Texture myGUITexture = Resources.Load("23") as Texture;
Debug.Log (www.bytesDownloaded);
Debug.Log (www.progress);
Debug.Log (www.texture);
yield return www;
// we put the downloaded image into the new texture
www.LoadImageIntoTexture(tex);
// new cubemap 
Cubemap c = new Cubemap(2048, TextureFormat.RGBA32, false);
Color[] CubeMapColors;
CubeMapColors = tex.GetPixels();
c.SetPixels(CubeMapColors, CubemapFace.PositiveX);
// we set the cubemap from the texture pixel by pixel
c.Apply();
//NewTexture.isPowerOfTwo = true;
//Debug.Log (RenderSettings.skybox.GetTexture ("_Tex"));
// We change the Cubemap of the Skybox
RenderSettings.skybox.SetTexture("_Tex", c);
}

我注释了所有代码来解释我认为我在做什么。

我做了一个逐个像素创建立方体图的"技巧"，因为编辑器的方式(顺便说一下，这非常简单(似乎无法从我可以阅读的其他人的帖子中实现。

最终，结果只是一堆灰色像素。

我真的不知道在我的过程中搞砸了这么多，我看到的唯一"阴影"点是 TextureFormat。

我之所以选择 RGBA32，是因为当我查看我的 Unity 编辑器时，我看到 BC7 格式，该格式被错误记录为 SetTexture 不可能，并且他们从文档中解释说它可能在 RGBA32 中解压缩。

当然，控制台中没有剩余的错误。

我真的很惊讶没有一个简单的方法可以做到这一点。我的意思是不一定从http中获取图像并将其放入天空盒中，而只是更改天空盒的纹理。我错过了什么吗？

Answer 1

我想我为你找到了解决方案。

以下代码基本上是代码的扩展。

我修复了一些困扰我的东西，但代码基本上是一样的。

using System.Collections;
using UnityEngine;
public class ReplaceCubemap : MonoBehaviour
{
public string url = "your file name";
public int CubemapResolution = 256;
private Texture2D source;
/// <summary>
/// These are the faces of a cube
/// </summary>
private Vector3[][] faces =
{
new Vector3[] {
new Vector3(1.0f, 1.0f, -1.0f),
new Vector3(1.0f, 1.0f, 1.0f),
new Vector3(1.0f, -1.0f, -1.0f),
new Vector3(1.0f, -1.0f, 1.0f)
},
new Vector3[] {
new Vector3(-1.0f, 1.0f, 1.0f),
new Vector3(-1.0f, 1.0f, -1.0f),
new Vector3(-1.0f, -1.0f, 1.0f),
new Vector3(-1.0f, -1.0f, -1.0f)
},
new Vector3[] {
new Vector3(-1.0f, 1.0f, 1.0f),
new Vector3(1.0f, 1.0f, 1.0f),
new Vector3(-1.0f, 1.0f, -1.0f),
new Vector3(1.0f, 1.0f, -1.0f)
},
new Vector3[] {
new Vector3(-1.0f, -1.0f, -1.0f),
new Vector3(1.0f, -1.0f, -1.0f),
new Vector3(-1.0f, -1.0f, 1.0f),
new Vector3(1.0f, -1.0f, 1.0f)
},
new Vector3[] {
new Vector3(-1.0f, 1.0f, -1.0f),
new Vector3(1.0f, 1.0f, -1.0f),
new Vector3(-1.0f, -1.0f, -1.0f),
new Vector3(1.0f, -1.0f, -1.0f)
},
new Vector3[] {
new Vector3(1.0f, 1.0f, 1.0f),
new Vector3(-1.0f, 1.0f, 1.0f),
new Vector3(1.0f, -1.0f, 1.0f),
new Vector3(-1.0f, -1.0f, 1.0f)
}
};
void Update()
{
// When trigger, we start the process
if (Input.GetKeyDown(KeyCode.F))
{
// start Coroutine to handle the WWW asynchronous process
StartCoroutine(setImage());
}
}
IEnumerator setImage()
{
WWW www = new WWW(url);
//Texture myGUITexture = Resources.Load("23") as Texture;
Debug.Log(www.bytesDownloaded);
Debug.Log(www.progress);
Debug.Log(www.texture);
yield return www;
source = new Texture2D(www.texture.width, www.texture.height);
// we put the downloaded image into the new texture
www.LoadImageIntoTexture(source);
// new cubemap 
Cubemap c = new Cubemap(CubemapResolution, TextureFormat.RGBA32, false);
Color[] CubeMapColors;
for (int i = 0; i < 6; i++)
{
CubeMapColors = CreateCubemapTexture(CubemapResolution, (CubemapFace)i);
c.SetPixels(CubeMapColors, (CubemapFace)i);
}
// we set the cubemap from the texture pixel by pixel
c.Apply();
//Destroy all unused textures
DestroyImmediate(source);
DestroyImmediate(www.texture);
Texture2D[] texs = FindObjectsOfType<Texture2D>();
for (int i = 0; i < texs.Length; i++)
{
DestroyImmediate(texs[i]);
}
// We change the Cubemap of the Skybox
RenderSettings.skybox.SetTexture("_Tex", c);
}
/// <summary>
/// Generates a Texture that represents the given face for the cubemap.
/// </summary>
/// <param name="resolution">The targetresolution in pixels</param>
/// <param name="face">The target face</param>
/// <returns></returns>
private Color[] CreateCubemapTexture(int resolution, CubemapFace face)
{
Texture2D texture = new Texture2D(resolution, resolution, TextureFormat.RGB24, false);
Vector3 texelX_Step = (faces[(int)face][1] - faces[(int)face][0]) / resolution;
Vector3 texelY_Step = (faces[(int)face][3] - faces[(int)face][2]) / resolution;
float texelSize = 1.0f / resolution;
float texelIndex = 0.0f;
//Create textured face
Color[] cols = new Color[resolution];
for (int y = 0; y < resolution; y++)
{
Vector3 texelX = faces[(int)face][0];
Vector3 texelY = faces[(int)face][2];
for (int x = 0; x < resolution; x++)
{
cols[x] = Project(Vector3.Lerp(texelX, texelY, texelIndex).normalized);
texelX += texelX_Step;
texelY += texelY_Step;
}
texture.SetPixels(0, y, resolution, 1, cols);
texelIndex += texelSize;
}
texture.wrapMode = TextureWrapMode.Clamp;
texture.Apply();
Color[] colors = texture.GetPixels();
DestroyImmediate(texture);
return colors;
}
/// <summary>
/// Projects a directional vector to the texture using spherical mapping
/// </summary>
/// <param name="direction">The direction in which you view</param>
/// <returns></returns>
private Color Project(Vector3 direction)
{
float theta = Mathf.Atan2(direction.z, direction.x) + Mathf.PI / 180.0f;
float phi = Mathf.Acos(direction.y);
int texelX = (int)(((theta / Mathf.PI) * 0.5f + 0.5f) * source.width);
if (texelX < 0) texelX = 0;
if (texelX >= source.width) texelX = source.width - 1;
int texelY = (int)((phi / Mathf.PI) * source.height);
if (texelY < 0) texelY = 0;
if (texelY >= source.height) texelY = source.height - 1;
return source.GetPixel(texelX, source.height - texelY - 1);
}
}

代码的基本作用是：

• 从www获取全景纹理
• 对于每个面，计算纹理
• 将生成的纹理分配给立方体贴图
• 收集垃圾
• 将立方体贴图分配给着色器

Answer 2

我将解决方案与计算机上的图像一起使用。

我遇到了一个问题，图像的颜色失去了强度，我发现这是因为sRGB没有设置为真。 我通过替换来修复它：

Cubemap c = new Cubemap(CubemapResolution, TextureFormat.RGBA32, false);

在setImage函数中：

Cubemap c = new Cubemap(CubeMapResolution, DefaultFormat.LDR, TextureCreationFlags.None);