Calculate the ratio of 1 unit to how many pixels?

[looeee]

You might find my functions from this post useful:

Functions to calculate the visible width / height at a given z-depth from a perspective camera

These two functions will give you the visible height and width in your scene at a given distance from a PerspectiveCamera. It’s useful if you want to create an object that is the full width / height of the scene, or want to place objects at screen edges etc. Here’s the code (ES6): const visibleHeightAtZDepth = ( depth, camera ) => { // compensate for cameras not positioned at z=0 const cameraOffset = camera.position.z; if ( depth < cameraOffset ) depth -= cameraOffset; else depth += c…

They’ll give you the full width of the screen in three.js units at a given z-depth. You can then use that to create objects that are a given percentage width, or do some more calculations to make them a particular amount of pixels wide. However, it’s probably best not to size things in pixels since on HDPI screens they will get very tiny.