Get position of vertices in Unity from 2D texture.

Hey guy,

I have 3D (.obj) file and texture file (.png).
.obj file have
v (vertices), vn (vertices normalize), vt (vertices texture), f (face/triangles)
.png is image texture of that 3D file.

I import both of them into Unity using Meshfilter for .obj and Mesh Renderer for texture file .png.

Then I create annotation on .png file, output look like {[(x,y), (x,y), (x,y), (x,y), (x,y),], text = "a"}
Is it possible to know the 3D position of annotations inside Unity?

What I'm trying so far.
1. I match the position of texture file to 3D file according to face, ex (x,y) = (0.3, 0.6) -> (-1.5, 0.8, -2.8).
I try using this 3D position inside Unity but the position do not connect to surface of mesh file, mean the 3D position isn't correct.
2. I try using only index and access the vertices index inside Unity, the position from vertices connect to surface of mesh file but do not close to character a on the mesh file. This mean my vertices index is incorrect.

To sum up,
I want to create function to translate vec2d position in texture file to vec3d position in unity.

If anyone have other idea please tell me.

 

I don't see you mentioning UV coordinates. You do know how textures work in 3D right?

 

This had been asked several times in the past. This one was about 10 years ago. So there's not necessarily a 1-to-1 mapping beween UV / texture coordinates and worldspace coordinates. It depends on the actual mesh and how it's mapped in texture space.