I’d like to know which parts of a blueprint are causing the greatest load and/or taking longest to execute, etc.
Is there a tool built into UE4 editor to record/monitor/report this?
We currently don’t have a tool for construction scripts. You can profile while the game is running (see Ben’s response and link).
That said, there is a very crude hack that you can use in some cases to estimate cost of construction scripts. This lies in the fact that blueprints have some code enabled that limits them from running over 1million instructions on the construction script. Some blueprints I have made for erosion algorithms actually hit that limit so I started figuring out how to optimize.
I found that you can estimate how many instructions a macro is etc, simply by seeing how many times you can do it in a forloop before you start getting compile errors. It should say somewhere in the log that your BP went over 1million instructions. Strangely, many BP’s still seem to compile in spite of the error, but they will just randomly be missing data beyond those 1million instuctions. In my erosion case, if I made the terrain 512x512, it would only erode half of the terrain before just stopping.
So you can see how many instructions just the ForLoop macro is. I think it was around 4, so I could do forloop just under 250k times before getting the warning. Knowing that you could start to get really crude data on other functions.
You can get some details by using the Stat Profiler, as described here: What are the in-engine tools for CPU and GPU profiling? - Debugging, Optimization, & Profiling - Epic Developer Community Forums
That should let you see which blueprints are slow, and you get some limited information on what kinds of events are slow.