Blueprint based Procedural Foliage parameter changes not being reflected after resimulation

Frequency: 5/5

Procedural Foliage created via the Blueprint method only reflects parameter changes on resimulation if the parameter in the Blueprint has been modified then compiled. After that, you can modify the parameter at will and resimulate the foliage without having to recompile the Blueprint after each parameter change.

Blueprint always shows need for recompile after a parameter change, but resimulate reflects the changes without recompile provided the Blueprint has been compiled once since that parameter was modified.

1. Download, unpack, and open provided project
2. Editor will open with ProceduralFoliageTestMap loaded
3. Go to Edit->Editor Preferences->Experimental and enable Procedural Foliage
4. Open the "Foliage-Barrel" Blueprint from the Content Browser
5. Select "Foliage-BarrelSpawner" in the World Outliner
6. Make sure you can easily observe the "Foliage-BarrelSpawner" volume while changing parameters in the "Foliage-Barrel" Blueprint
7. Navigate to Procedural > Clustering > Num Steps inside of the "Foliage-Barrel" Blueprint and change it to 5
8. Navigate to the Details panel and click the Resimulate button under the Procedural Foliage rollout
9. Observe that nothing changes in the scene
10. Compile the "Foliage-Barrel" Blueprint
11. Click Resimulate once again
12. Observe that the crates are denser
13. Change Num Steps to 6, but do not compile the blueprint
14. Click Resimulate once again
15. Observe that the crates are even denser, in spite of not compiling the change
16. Navigate to Procedural > Clustering > Initial Seed Density inside of the "Foliage-Barrel" Blueprint and change it to 6
17. Click Resimulate without compiling
18. Observe that nothing changes in the scene
19. Compile the blueprint
20. Observe that the crates are even more densely packed