I personally don’t know of any ways to do it in shotcut except for using a pre-made image as you said with the size and position filter on distort mode. it is a good idea though.
Is that necessary though? Importing a rectangle as a picture and using the Size and Position filter does not seem to be the most tedious task.
There are already so many suggestions that this seems like a luxury. Perhaps it is easy to implement but then many would ask why there are only x shapes present and that this particular one is used so often, it has to be implemented as well. I have the feeling the developers have enough on their roadmap.
I am not opposing this idea I am just questioning the necessity.
I know why I like this forum . In other ones questioning means an attack on a person .
By the way, you could also think about highlighting instead of using a rectangle.
The following video shows that - his explanation is a bit erratic though:
You can tweak the code to get the rectangle at a different size and/or position, and/or make the blue background transparent, and change the border width and/or colour…
You could then either:
add this code to a colour clip and chroma-key out the blue background - unless you made it transparent),
Use the size/position filter to position it where you want.
From v.19.06 onwards, apply to a transparent clip (text:HTMl filter).
Here’s the code - to convert to a HTML file, copy, paste into notepad, save as .txt file, replace .txt with .html
(sorry, you may know this detail, not sure of your experience level).
Here is the result with the above HTML code applied to a transparent clip on V2. I re-sized and positioned the red box with the size/position filter. I’ve added a fade-in and fade-out. Watch how the red box appears over bar 2 of the music.
It’s also possible and very easy to use a color clip with 2 or more mask simple shape filters to create boxes, rectangles, circles and other shapes. Rotate and scale, and size and position filters can be used to position, size and rotate the shapes.
Use text filter. Select wingdings or dingbats font find a square. I personally use the pointy fingers G or H . You may be able to stretch the square using size and position with distort enabled. The order of your filter layers will be important, dragging them around with trial and error. It might require a separate video track of green screen ,and a simple chroma key.
Wingding finger is much less fussing about.