World Position: calculate in vertex or fragment

Hi all,

I am seeing 2 different ways of computing pixel world position in shader (for volumetric effects).

1. Calculate "camera to far plane" vector in vertex shader and pass it to fragment shader, then using depth and camera world position to calculate pixel position.

2. Calculate the whole thing in fragment shader using uv data (texcoord).

Are there any pros/cons for these 2 approaches?