I had subdivided a plan by 100 times and when I tried to apply the “Skin” modifier, Blender locked up. That is, it is showing “Not Responding” and I cannot do anything with the UI including saving the file. If I see the task manager, Blender has been taking one CPU thread 100%.
It is not the only time I have seen things like this. It happened when there are many vertices or edges and I try to apply something.
Why is this so? Why is the UI not responding? Why does it do a lengthy task on the UI thread? And why doesn’t it use all the CPU cores?