Grease pencil retopo button missing

I am practicing retopo from a sculp and following a tutorial whereby grease pencil strokes are drawn on the mesh, and then turned into vertices by clicking the retopo button from the tools panel. I can draw the lines, but the retopo button isn’t there. I have bsurfaces gpl enabled. Am I missing an add on? 2.68.

There’s something weird going on with the tutorial. I think the author has shortened it cutting out the grease pencil methods as they must have been changed/removed. There is the full 14 minute version with grease pencil 5-6 minutes in. The short version stops around minute 5. Sometimes I can watch the full 14 minute version, sometimes I can’t, I’ll embed it at the bottom.

What I want to do is draw lines with the grease pencil, have them projected onto the sculp, and then convert them into verts/edges/faces where they intersect.

I can do this in a more manual fashion by control left clicking with snap enabled. But I’m trying to speed up the workflow and make it more natural. When it try using the convert button it isn’t creating the edges I want, and in addition it is adding a whole bunch of keyframes, and I’m not sure what’s going on there.

The tutorial link:

The tutorial video:

Ah i see, in the beginning he shows the addon he is enabling, and one of them is “Grease Pencil Retopology”, never used this one before.
It’s a contrib addon, meaning it’s removed from the “stable” releases of Blender (every addon from the contrib_addon folder are always removed from the stable release), but can be found in buildbot by example.

Unfortunately it looks like the addon is broken in current version of Blender as clicking on the retopo button after grease pencilling something just lead into an error and no topology is generated.

For what you want to do, try to use the Bsurface, it is still working in current version.

As an exercise in python and if you really want Retopo button to work (which comes from Grese Pencil Retopology Addon :

in file \2.68\scripts\addons_contrib\gpencil_retopo\
change lines 511 to 515 to look like this

    # remove double faces
    faces = dict([(tuple(sorted(f)), f) for f in faces]).values()
    fc_lst = list(faces)
    mesh ="Retopo")
    mesh.from_pydata(verts, [], fc_lst)

Edit: It would work after this hack, but for simple things, like some quads. Even then, expect surprises.

Wow, thanks eppo. That is going the extra mile!

I got it working after banging at it long enough and changing the code per eppo’s hack. I haven’t seen any weirdness and it seems to work perfect (for my simple tests anyway)

I’m a little confused to the difference between this and bsurfaces. Is the control-left click style snap/extrusion bsurfaces at work?

And thank you @eppo, much appreciated.

You can combine any mesh building tool while doing parts of retopo using Bsurfaces/GPdraw. Ctrl-left click is Blender’s (proprietary ;)?) tool and it works if you have selected vertices too.

And thanks for ‘thanks’ of course!

With Grease Pencil Retopo i was getting difficult to remove extra faces and when i tried to extend that circular pattern with some more GP strokes blender would hang with 100% CPU load and could not be stopped anymore.

May I ask you, where did you got this addon? How can it be found?

Hi 1D it’s in the testing’ addons section which I guess is only in the builds not the official releases. I don’t think anyone’s touched it up for a long time, are you going to apply your magic skills to it?