User:Yiming/LineArt As GPencil Modifier

Line Art As GPencil Modifier FAQ

Updated 2021/03/17

This document discusses the current limitations and workarounds based on the evaluation process of Line Art under the management of Grease Pencil Modifier.

Problems

Nothing shows up when I add a line art object!

There needs to be an active camera in scene. Line results are generated from the view of that camera.

It's too slow compared to past experiences!

Due to lack of global cache at the moment, each line art modifier will run the entire occlusion calculation for itself, so if you have multiple line art modifiers to select different parts of the scene (to apply different styles etc.), the process is going to cost you multiple evaluation time.

Solution is being considered and developed at the moment, at the mean time you can choose to use lanpr-under-gp branch, which is the cached line art branch, the UI won't lock up when you adjust things, but the cache not done in a "standard" way. You can use this branch to speed up your process, but there are slight differences between this and master code. This branch will become obsolete after we incorporated a proper caching mechanism in master.

Also, a multithread loading and intersection calculation is under development and will be available shortly.

Intersection lines will appear outside source collection!

Due to the way line art calculates intersection lines, they can not be distinguished on a object/collection basis. There will be a temporary solution coming real soon, which is to eliminate intersection calculation outside selected geometry source. We are also developing a new intersection selection method that can be efficiently integrated in line art that doesn't slow down the calculation yet provide enough flexibility.

There are phantom connections across geometries!

You have set the chaining threshold too big. Lower that value so lines that are too far apart from each other won't connect.

The line does not select when a edge mark is on a contour line.

This is currently a limitation of line art and will be addressed in the future.