UI Opacity

[togetherwithasteria]

What problem does this solve or what need does it fill?

This allows fade-in fade-out transitions for UI bundles, and setting the overall transparency of UI bundles, which I think is useful in many games to unclutter the window when it's not really important (but may be needed) or as a configuration in games for players who wish to unclutter their view and see more what's going on.

What solution would you like?

To be discussed.

What alternative(s) have you considered?

For my own game, I am considering trying to do pop-in pop-out animation with Transform. It allows a more cartoony transition, but for others this might not been what they prefer for their game theme.

It's possible to change the opacity of TextBundles and background colors but that's a major hack and can't be used with ImageBundle

Additional context

https://developer.mozilla.org/en-US/docs/Web/CSS/opacity

[viridia]

The way I would like to see this done is with buffered rendering. So for example, if you have an animated dialog that needs to transition (fade-in, scale, etc.) it would be rendered to an offscreen render target, and then the render target would be rendered to the main view. This allows you to control the opacity of the entire dialog, instead of making the children individually translucent (which would look bad).

I propose that there be some Component that you attach to a UI node that says "render all of the children of this node onto this offscreen rendertarget", at which point the node itself simply sets that same render target as its background image. You can then either introduce a new Opacity style property, or use the existing behavior where the alpha component of the background color is multiplied with the background image.

[togetherwithasteria]

This allows you to control the opacity of the entire dialog, instead of making the children individually translucent (which would look bad).

Yeah. I'm not exactly sure if this is accurate but generally in raster programs, opacity in folders works but occasionally normal mode makes it better?

[UkoeHB]

See #15256 for a proposed solution.