I really don't understand how UI scale works in world space.

I'm trying to create a UI overlay for an entity in my game. Things in my test scene are on the scale of 1-10 Unity units.

I create a world-space canvas under the game object; it's 100 by 100. No problem, I just resize it. I create a button subordinate to the canvas. It's 160 by 30. Resize to 5 x 5. Now it's super pixelated, as though the button is intended to be viewed from a much wider scale. After some fiddling, I fix that problem by reducing "Reference Pixels Per Unit" on the Canvas Scaler component. Not sure how that works, but it works. I try to change the text on the button. No text shows. On a hunch, I restore the button to it's original size, and the text is there. When I shrink the button, the text stays the same size and the button contains only white-space. This is 14pt font, which means that it should be 14 pixels high. But on what monitor?

These 14pt letters would seem to be about ten unity units high. I can't set the text to 0.3pt size; that's ridiculous and Unity won't let me. Obviously, I'm failing to understand something very fundamental about scale in Unity. Would someone help me, please?

 

To make a world space canvas act the way you expect, you'll want settings similar to these:

Transform scale: <0.005, 0.005, 0.005>
Transform width: 400 height: 300
Canvas render mode: World Space
Canvas Scaler, Dynamic Pixels Per Unit: 1
Canvas Scaler, Reference Pixels Per Unit: 100

The key is probably the first one above. If you don't scale your canvas down quite a lot, you will have suffering and grief.

 

@JoeStrout

Looks like that does it. Thank you! But now I wonder: since this feels like a fairly extreme squeezing of the Unity standards, might it be better in the long term if I just scale everything up by a couple orders of magnitude?

 

No. The standard is for 1 unit of Unity space to be 1 meter of virtual space, and there's no reason to deviate from that. Canvases are designed with a different convention, 1 unit ~= 1 pixel, but that was because they were originally intended for screen-space work. When you're using them in world space, it is expected and perfectly normal to scale them down.

 

Thank you just answered today's question, so its best to make the UI a standard size and then use scalling to get it to fit where you want when in world space. Lucky I saw this I had went the other way had set my first batch up at .4 size