Use Davinci Resolve shape transitions to create custom effects between video clips. This video tutorial shows to to change the duration of the video transitions, add a custom curve to the transition, add a border to the transition. Once all of the changes to the transition are made, the custom transition can be saved so it can be used again in any project. Shape transitions are easy to set up in Davinci Resolve 15 learn the basics and drill down into the details of some of the more advanced features for your project. There is a lot of flexibility using davinci resolve transitions.
This video shows the basics of heart shape transitions in Davinci Resolve
Box transitions - both vertical and horizontal box transitions
triangle transitions in resolve
star transitions in resolve
The tutorial also shows how to create a border or blur on the custom Resolve 15 transitions.