Using Mesh Geometry (Edges) or Curves as Grease Pencil Guides?

[KevinMcKraken]

So, when I get free time at work, I like to work on Blender projects. Freestyle isn’t working out for me anymore, and I’d like to use the Grease Pencil tool to draw the lines by hand. However, I cannot use my tablet at work, and I’d like to have more precision on drawing the lines. Which leads back to the title of this question: Can I use mesh edges, or curves to act as guides for the Grease Pencil tool? Is there a better way?

Thank you!

[FlyingBanana]

You can draw on the surface of the 3d object by selecting surface and object but you will still have to maintain drawing in the 3d objects location. It will then follow the geometry of the object as you can still draw outside the 3d object space and it wont snap the grease pencil strokes to the object. That’s about all I know about the grease pencil. Not sure if that is what you were looking for.

[KevinMcKraken]

Not quite, I was more hoping that I could use the physical edges as a guide for precision drawing. I appreciate the reply!

[LoboTommy]

Hi. What’s wrong with Freestyle? You can Mark Freestyle Edge to have specific ones be drawn by it.

Anyway, if you’re intent on the GP way consider the various answers here:

Convert Curves to Grease Pencil?

Can also try drawing in GP line or poly mode with snap to vertices active, or you could edit drawn stokes / points after with said snapping.

Another line rendering option is being developed in / for 2.8:

Blender 2.8 LANPR [GSoC 2018]

[lanpr] Yiming Wu have just dropped his/her latest build. To witness such line-art NPR come alive (in a real-time environment), it’s an amazing feeling itself. The scene tested here is the Wanderer from Daniel Bystedt. From one of Yiming Wu’s tweets, “… Different line types can be adjusted. NPR artists, I need your thoughts on the legacy Freestyle, what is good and what is bad. I’ll plan the render structure based on your feedback!”

[KevinMcKraken]

Thanks! I love Freestyle, I’ve used it for years, but I’m hitting a wall, where I want the lines drawn in a specific way, but I’m not good enough at Python to see if it’s even possible to draw them how I want. I’ll check out what you’ve got here.

[LoboTommy]

Re:

@KevinMcKraken

want the lines drawn in a specific way

look up Freestyle line styles and modifiers. Can use tiling textures even.

[KevinMcKraken]

I know about them, I use them frequently, but the way they are drawn, the way the chaining breaks by default is really throwing off the appearance of my renders.

As you can see, the top of the arch breaks at every intersection, and I want it to follow the longest edge, say breaking only at angles under 160deg. I have tried many things to achieve this, with no success.

[LoboTommy]

Any of this discussion help?

Trying to close gaps in Freestyle lines

When I have a sphere-like object that becomes too narrow, I start seeing gaps in my Freestyle lines. Can anyone explain why this is happening? [image] My Freestyle settings: [image]

[KevinMcKraken]

I tried some of what was shown, but still having odd chaining. I found a solution, but it’s rather undesirable to me, which is layering the mesh by splitting chunks and moving them slightly apart, then using sketchy chaining to hide what area I don’t like too much. Which, I already do for certain objects, but if it works, it works I suppose.

Thanks for your help!

[LoboTommy]

No probs. If they’re just plain lines like that then GP could do the job. If you try it I’d recommend one of the scripts from stackexchange to draw GP strokes on your mesh edges.

That said it seems that Freestyle is capable of smoother results considering examples such as:

Could be that one object draws better than multiple.
Could be a subdivision surface modifier helps the look (applied or not).
Perhaps someone else knows some other setting(s) to tweak or tricks?

Anyway, good luck with it.