Set custom texture

Hi,
first of all, thank you for making such a great interface! It is really useful and easy to tweak.

In my work, I often need to visualize textured meshes using parametrization.
The textures provided are not enough, unfortunately.
The best solution would be is to use an image as texture. Example of a texture.

I am willing to code it myself, however, I am not sure where to start.
How can it be done? What files/functions should I look into?

Thank you!

该 issue 未指出任何文件、测试或函数。首先定位 polyscope 现有的网格纹理和参数化入口点，然后确定图像纹理应如何接入 viewer API。完成的标准是：带纹理的网格可以使用用户提供的图像，并与链接的示例一致。