I have been creating some 3D spaceship models in the style of Star Trek The Animated Series (example below) and learning lots about cel shading effects and creating outlines with the line art modifier and grease pencil. It’s a lot of fun!
One issue I am having is with grease pencil lines floating above the surface of the model, or else being too close and clipping. One partial solution I am aware of us to create a special solidify mesh to better control the offset consistency, but the basic problem remains.
So I was wondering about ways to fix this? My first thought is to use a fresnel shader to make the surfaces become transparent at near-90 degree angles. But then I wondered if there was a way to use the rendered alpha channel of the ship to clip the grease pencil layer somehow? Ideally without having to render out in separate layers first. Would that be possible?
Something you might want to think about is to have two different Line Art modifiers, one for larger details (overall silhouette of the larger ship parts, nacelles, ball, etc) and one for smaller ones (gribble outlines, windows, etc). The two will probably tend toward having different needs, so you can tweak settings like distance from the mesh separately. For example, in the example of the window at the top of the ball you highlighted, nudging the overall shape outward a little bit or thickening its line could cover up where it’s billowing out a little bit.
In fact, you could have an entire Line Art modifier just for gribble/detail lines! You can designate them by giving them their own material and then assigning that material to polygons in the mesh you’d like to outline, then select “Material Borders” in the Edge Types.
One last tip is that you might find it useful to include an offset modifier, and then animate that offset to the needs of any given shot.
Thank you Matt, some useful thoughts there! I’ve been reading the documentation and see that there’s a lot more flexibility to line art styles than I had realised! The style I’m imitating is pretty simple, but I could still improve my results.
Animating the offset is a great suggestion! Can you use that to inflate the grease pencil lines? I will investigate!
If I understand what you mean by “inflate,” all you’d need to do is keyframe the “Line Thickness” in your Line Art modifier!
Incidentally, I love using Blender to emulate different mediums and old styles of animation. Star Trek: TAS is exactly the kind of thing that’s a fascinating choice to me because so much of the look of that series came from the technical limitations of the time, which means that getting it just right requires so much restraint and intentionality when using Blender. Really looking forward to seeing more, keep it up!
