Change Texture Shape of a texture through script

Questions & Answers
1

Hey, is there any way to change the texture shape of a texture through a script?

I know how to do it using the Import settings (see image) but I was wondering how to do this inside of a script, at runtime.

154416-ashampoo-snap-20200317-17h24m45s-001.png

Thanks a lot!

2

Update: After digging through endless forum posts, I’ve solved my original question of getting a URL to a skybox.

I hope this helps someone with the same problem!

using System.Collections;
using UnityEngine;

public class LoadImageToSkybox : MonoBehaviour
{
    public string url = "Your URL Here";
    public int CubemapResolution = 512;
    Cubemap c;

    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)
        }
    };


    private void Start() { // When the game starts, apply the skybox texture
        StartCoroutine(setImage());
    }

    IEnumerator setImage()
    {
        WWW www = new WWW(url);

        yield return www;
        Debug.Log(www.bytesDownloaded);
        Debug.Log(www.progress);
        Debug.Log(www.texture);


        source = new Texture2D(www.texture.width, www.texture.height);
        // we put the downloaded image into the new texture
        www.LoadImageIntoTexture(source);

        // new 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*);*

}

// We change the Cubemap of the Skybox
Material cubeMapMaterial = new Material(Shader.Find(“Skybox/Cubemap”));
cubeMapMaterial.SetTexture(“_Tex”, c);
RenderSettings.skybox = cubeMapMaterial;
}

///


/// Generates a Texture that represents the given face for the cubemap.
///
/// The targetresolution in pixels
/// The target face
///
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;
}

///


/// Projects a directional vector to the texture using spherical mapping
///
/// The direction in which you view
///
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);
}
}

3

This worked! I needed to change my sky dynamically for a computer vision perception project.
Here is a quick and dirty snippet applying this code to my use case. Note, I modified the CreateCubeMapTexture and Project methods to take the texture as parameter instead of using a class variable.

volumeObject.GetComponent<Volume>().profile.TryGet(out sky);
var c = new Cubemap(CubemapResolution, TextureFormat.RGBA32, false);
Color[] CubeMapColors;
for (int i = 0; i < 6; i++)
{
     CubeMapColors = CreateCubemapTexture(CubemapResolution, (CubemapFace)i, _texture);
     c.SetPixels(CubeMapColors, (CubemapFace)i);
}
c.Apply();
sky.hdriSky.Override(c);