I want to implement some kind of ‘hud’ on the ‘glass’ curved surface. Initialiy I was thinking about some decals but now it seems decals can’t be placed on curved glass surfaces?? at least I can’t get it to work.
For example something like this:
Ohw and important is that most is ‘dynamic’ / movable… for example target selection boxes.
Anybody have any tips / hints on how to implement this?
Thanks in advance!
Hmm normaly when there is no answer on this kind of posts it means it is very easy and i’m looking at the problem from a wrong direction…
Anybody any hints? like keyword of technics to use?
I think if noone answers the question is not too easy but too difficult. Easy questions get lots of answers. 
You cannot project a hud yet the way you like with engine standard tools. 4.6 will have a way to project your UI to meshes.
Decals don’t work on transparent objects afaik (well transparency is kind of lacking in ue4 in general if you ask me) but you don’t need a decal to render a texture on an object in the first place! 
you can use a translucent material on the curved mesh with masking etc. then you could pass parameters to move the “target boxes” around but that’s probably going to be a bit complex to implement.
But that approach won’t get you very far anyway, especially if you want dynamic text stuff on the screen (which cannot be done with a material).
You can wait for 4.6 or use one of the html ui plugins to render on the mesh (although I do not know if all of them have proper transparency support).
I think normally would be floating UI elements near the glass so TK-Master is right, with 4.6 you can use a UMG component or use them in 2D space using project to figure out the right place and then skew the 2D element to mostly match
If you just want text, my recommendation would be to use Text Component, and have them slightly offset from the curved surface. Might be imperceptible, might even look kinda cool, more 3D/sci-fi. It will be much cheaper than using the 3D UMG widget (Also the first version of the 3D widget has no support for custom meshes), or attempting to do with with canvases and a render target (depending on if you update it every frame).
Thanks for taking the time to reply! I’am currently making my hud a bit simpeler / static so I can make it with simple material / translucent / masking.
Will revisit my hud if further down the line updates to the UE engine give more possiblibities with decals / curved sufaces and glass.
Again thanks for reading / taking the time to reply.
