Here are the UMG answers for your list:
- Curved / Dial shaped bars which fill and empty (Yes - Material)
- Curved / Radial shaped bars with fill indicators which light up rather than a filled shape (sprite sheet?) (Yes - Material / Blueprint brush swapping)
- Bars which have unique shapes and thus require unique fills (Yes - Progress Bar)
- Animation effects such as glow pulses (We don’t have arbitrary effects out of the box you can apply, no glow checkbox or slider, you’d need to bake it into a flipbook texture and use a material)
- Animation effects such as line movements (Yes Animation - but we animate widgets and widget properties and but don’t have primitives like lines you can animate)
- Projection of 3D models onto a 2D element (is it 2D, is it 3D, is it a sprite? (Yes - Render Targets)
- UI Elements will have transparency (Yes)
- Glow, Colourize/Tint and Alpha transitions (Yes - But not glow)
- Execute sound when ui element is clicked (Yes)
- Events for mouse over, mouse out, mouse down, mouse up, click (Yes - For user widgets yes, not every widget allows inspection/handling of those events, likely will in a future version)
- Low CPU/GPU consumption (I’ve noticed a lot of AAA games these days the menu screens can take more CPU/GPU than many parts of the actual games!) (Depends - Slate/UMG has efficient rendering but you can make it slow just like any other system)