Yesterday, I worked on the next page of Rita. It includes a figure lying under a quilt. I decided that this was a perfect job for a distortion mesh; I grabbed some regular gridded details from an earlier page, turned them into a pattern fill, and started futzing about.
I started to notice some distinct quirks about how the mesh was behaving as I started to push it into overlapping itself. I did some crude patches to work around it, but I felt like I still had things to learn. So when I got up today, the first thing I did after showering was to open up a new document for the specific purpose of exploring how distortion meshes work.
THINGS I HAVE LEARNT:
– Illustrator does not guarantee that a self-overlapping mesh will be rendered the same way as it’s rotated. Look at the bottoms of the mirrored images. It seems to render the leftmost pixel of the undistorted imagery, and either completely drop, or merely hide, the rightmost. (I need to do a test with multiple vector shapes inside the mesh instead of the bitmap I used here – that’ll tell me exactly what’s happening here.) Presumably there is also some sort of painting order going on from top to bottom, as well.
– If you want to simulate drapery, you need to add more mesh lines, and push them around so that there’s no self-overlap where the drape goes behind itself.
– If you need to break a mesh point’s curve handles into a corner, you need to switch to the pen tool and break it with that.
– It is probably best to create a regular grid for purposes of draping stuff. Possibly both in terms of the mesh you create to do the distortion, and the imagery you’re distorting? I will have to explore this when I do my proposed exercise of drawing a figure with mesh-distorted patterns on all their clothes. Possibly as a standalone image, possibly as a costume change in Rita…
I wonder if it would be possible to automate the process of adding more mesh lines to hide self-overlap? I may have to see how much detail of a mesh is available to scripts. But later for that. I have a page to finish.