Slow render of large number of top level objects

[lorenzncode]

I tested performance of a VTK.js based viewer, cadquery.fig, and CQ-editor with large number of shapes at top level. It looks like there may be room for CQ-editor performance improvement for this scenario. See video. Both the VTK.js viewer and CQ-editor run the script on the left. The second script calls cadquery.fig show.

from cadquery.func import *

num = 1
#num = 40
for i in range(1, num + 1, 1):
    for j in range(1, num + 1, 1):
        globals()[f"b_{i}_{j}"] = box(1, 1, 1).move(
            x=1.1 * i,
            y=1.1 * j,
            z=0,
        )

perf_compare.mp4

[jmwright]

Do you know what VTK.js is doing differently? I have a multi-threading branch which seemed to help performance, but the GUI thread still stalled, and fixing that was the goal of the branch.

[lorenzncode]

@jmwright The VTK.js viewer should have more overhead due to server sending data to browser so I expected CQ-editor to actually be faster. I've made a performance change in #589.

perf_fix.mp4

[jmwright]

Fixed in #589