I am looking for a tool for 3d modeling in first person.  I don't have a VR set.  I find it difficult to model with no sense of scale and only a vague sense of depth.  That's when I had the idea of first person movement, such as walking flying, and jumping across models and environments.  Is there any such tool?

I only know of https://www.gravitysketch.com/

Check it out.

Great Idea! I think that with the popularity of VR the option of modeling in first person will become standard in the future.