改变材质的质感

Question

I'd first like to apologise beforehand if my question is very basic and dumb as I am very new to coding and unity/vuforia in general.

I'd like to track a custom image and display a quad under it (i've done this part). I've also managed to set the material/texture/look of the quad to a image located in my computer. However, when trying to do build into a android app, I am unable to set the file path correctly and it doesnt work.

I would like the material/texture/look of the quad to be constantly changing/updating, is this possible? I can constantly overwrite the image file on my computer/phone but will the photo update in the app itself?

Thank you so much for any help in advance!

A desperate student

   void Start()
    {

        string path = "file://storage/emulated/0/Android/data/com.kenny.argame/files/im2.jpg";
        StartCoroutine(DownloadImage(path));
    }


    IEnumerator DownloadImage(string MediaUrl)
    {
        GetComponent<Renderer>().material = FinalMaterialRef;

        UnityWebRequest request = UnityWebRequestTexture.GetTexture(MediaUrl);
        yield return request.SendWebRequest();
        if (request.isNetworkError || request.isHttpError)
            Debug.Log(request.error);
        else
            _material.mainTexture = ((DownloadHandlerTexture)request.downloadHandler).texture;
        FinalMaterialRef = _material;


    }

}

Answer 1

While it's not clear from your code where _material and FinalMaterialRef are originally declared -- they're not in the scope you showed -- you might have your references mixed up and overwrite them, but not the actual material. This works:

using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

public class ChangeTexture : MonoBehaviour
{
    Material material = null;

    void Start()
    {
        material = GetComponent<Renderer>().material;

        const string path = "file://E:/_temp/1.jpg";
        StartCoroutine(DownloadAndAssignImage(path));
    }

    IEnumerator DownloadAndAssignImage(string mediaUrl)
    {
        UnityWebRequest request = UnityWebRequestTexture.GetTexture(mediaUrl);
        yield return request.SendWebRequest();

        if (request.isNetworkError || request.isHttpError)
        {
            Debug.Log(request.error);
        }
        else
        {
            material.mainTexture =
                ((DownloadHandlerTexture)request.downloadHandler).texture;
        }
    }
}