Question by deprofundiis · Jan 26, 2015 at 12:39 PM · ui

How many canvas per scene? [UI 4.6+]

Couldn't find any direct answer to this so here goes:

I have many objects in my scene that use the new UI features/components/objects as per the image below:

alt text

Each object you can interact with will, at the present moment, have the same structure as the one you see above. Since I am just starting to learn how to use the new UI I have the following doubt: If I have 100 objects in the scene, will I need to have 100 canvas or is the current object hierarchy plain wrong?

Thanks a lot for your time.

screen-shot-2015-01-26-at-123526.png (20.4 kB)

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stevecus · Jan 26, 2015 at 04:24 PM 2

It all depends on how the UI is used. For example, if each unit/object has Ui elements that move independently with the object and not the other UI elements ( a good example is health bars) then yes I have found the best way to do it is to have a canvas on each object. I would however recommend anything like mouse cursors or build/action panels to be placed on one or two canvas'. You can also script to move the position of the elements if you wished to have everything on one canvas but I imagine that would get messy with 100 objects.

deprofundiis · Jan 26, 2015 at 04:40 PM 0

Thanks for taking the time to answer this @stevecus. Indeed the UI elements are related to each object (they are context action buttons like INFO, USE, GRAB). My question also goes a bit further to try and understand if my decision will have an actual impact on the overall performance.

stevecus · Jan 26, 2015 at 05:48 PM 2

As far as I am aware with what i've read and used, the canvas uses very little but I can't comment on certain devices, especially as I imagine all your UI will not be showing at once but rather enabling/disabling you should be ok. From some of the tests people have done and posted on the forums having seperate canvases is a better method as you can use culling where, but there are tests with a canvas with around 100-300 UI elements before they had framerate drop. I've been using it in a RTS with each unit/building having a canvas and not had any problems. As someone once told me, "Make it work then worry about making it better"

deprofundiis · Jan 26, 2015 at 05:52 PM 0

Awesome @stevecus! Thanks a lot for your time. Much appreciated!