Unity纹理投影与UV贴图

Question

I want to ask something about texturing in Unity.

I am new to Unity and I need your help. I have an idea to make a custom viewer for my 3D reconstructed mesh. So, for people that is not familiar with it, it is basically a method that convert 2D photo sequence to 3D mesh using a method called structure from motion. So, the output of the SfM is mesh and number of cameras. The idea is that I load the mesh and cameras (as projector) to Unity. Next, I want that if I click a button related to a certain camera, then the image that seen by that camera is projected to the mesh.

example of reconstructed 3D model

example image that seen by the camera:

example image that seen by the camera

So, the thing that I want to ask is, which method is better to put the image as texture to the mesh? Should I make UV map for each image and later switch it on and off or can I just use projector to project the image to the mesh from each projector? But I think, if I use projector, the texture resolution must be square. Since my images is not square, so it is impossible, isn't it? Or does any of you have different idea or suggestion about how to do it?

Thank you very much.

Answer 1

In your reconstructed model your mesh is a tessellation of the cameras tracking points cloud and not a single mesh.

You need the exact info of each point and this is what you get with the UVmap.

Proyection image not use this info, you can got good results but need to move, scale, rotate to a good position. But ever you got deformation in the images to adjust to the model shape in native proyections (spherical, box, cilindrical, etc) ,you never got exact shape with proyection, only an aproximation. On proyection you need to readjust texture setting if you move your model in the 3d space.

With the uvmap you have the "skin" of your model. If you make a nice Unfold you get the shape of your model with a very low deformation, near to the exact shape. You can move the model in the 3d space withouth modify any setting on the texture.

And another advantage is that you directly got your UVmap and their color info from the photo secuence. Not need another extra step, making proyection textures to not get better results.