Topic: Bsurfaces and Line conversion in Blender 2.6.9

[Zachary1234]

There are 3 tasks that my exercises and viewing of tutorial videos havn't helped much on.  Could someone
just reply with practical answers, if possible?

-What do I actually do to get bsurfaces generating between two Grease Pencil lines?
I can put down a plane and get the bsurfaces menu to show in the <t> area, but it hangs whenever I get it to go and or does nothing. How do I get it to run and give me the resultant grid, with the new options thereafter?

-What is the keyboard shortcut for subdivisions on a path? How may I select all subdivisions on a path?

-How do I turn a straight, individual path into a bezier, as well as in place too? How may I turn an individual straight path, composite paths, and beziers into a grease pencil line, in reverse (would need to for bsurfaces and other options)? Otherwise what would you do with aid in drawing nicer grease pencil lines?

[kat]

If you want to do something to a collection of objects whilst a Grease Pencil line is in the scene you'll first need to properly convert it into something Blender can deal with - I don't use GP so can't say for sure but read the docs for that feature here "Converting Sketches to Objects"? You may need to do some fiddling depending on the complexity of your 'sketch'.

The ToolShelf is context-sensitive so if Blender isn't hanging completely then it likely means the feature you're trying to access is not currently available based on what you're trying to do. Are you wanting to sub-divide the plane after it's been converted to a B-Mesh?

Read through the doc to learn how to change the character (type) of Bezier points

[Zachary1234]

Converting Grease Pencil to a mesh or bezier curve is never a problem; I can click on <convert> in the <n> area for Grease Pencils after drawing, and I can Click the "disable joining" little text box. I can even use <<alt> + <c>>  to shuffle between curves and meshes.

- My problem is converting a path into a bezier, and a bezier back to a Grease Pencil again, since I need the handle assistance under edit mode <tab> for those to get my shapes just right, and free handing with Grease Pencil isn't accurate enough for curves to start.

- From there, my second problem is turning at least 2 Grease Pencil Lines into the opposite edges of a corelative surface, using BSurfaces. What state do 2 opposite beziers need to be in? Do you have to start from grease pencil only? How do I get Bsurfaces to show me the <add surface> button, to draw it's extrapolation for me?  I've found the buttons, keys and mouse click too confusing here.

[EDIT] cleaned up text alignment. kat.

[kat]

I could be incorrect on this as I don't use BSurfaces, but so far as I'm aware it's not possible to convert paths or Beziers back into Grease Pencil lines because the latter isn't an editable object until it's converted into something, especially so if you've done something to the Bezier after conversion (destructive editing) because you would have then changed the form of the original line from which the Bezier Curve was generated. Don't quote me on that though.

Again don't quote me on this as I don't use Beziers that much either, but you can't 'mesh' with Beziers themselves because they're 'lines' (points along a path), they either have to be converted into an 'editable object', or they can be edited based on tool selection, switching into 'Mesh' edit mode for example when in BSurfaces, from whence the normal mesh editing tools are available for you to 'fill' or 'bridge' gaps as it appears you need to do.

There's a surprising amount of information available online about how Grease Pencil can be used, it may just mean you wrangling it to do what you're trying to do.

- Review of BSurfaces
- Drawing with Grease Pencil I
- Drawing with grease Pencil II

[Zachary1234]

- Don't worry about my bsurfaces question, since I have got layers and bsurfaces all working as desired. My problem now pertains to lines. To help with my modelling, and to provide me with all desired options, I need 2 things now:

- If I have a path which is a series of straight line, in <tab> edit mode, how may I select a desired cross segment of multiple sub paths, all all paths at once?

- How may I convert an already drawn straight line path into a bezier curve, with its dual end handles to help with curvature?  Mainly, how do I convert an individual or multiple "path path", or a bezier curve, or a combination of the two latter curves, into a Grease Pencil curve? I would need to go from paths or beziers to bsurfaces, since I need the special handle assistance to give me better precision for curves that Grease Pencil gives me when drawing with it.

Can someone tell me what to do with these, please?

[kat]

As for the additional questions: I'm not entirely sure what you're trying to do but if you're simply wanting to select nodes from two separate line elements (both being part of the same Object), you're likely going to need to guess which points form a 'valid' cross-section (assuming they haven't been bridged with faces yet - without faces or other connecting element to indicate which nodes form a pair), guesstimation is pretty much the only option available, assuming both lines have the same node density.

Read the documentation linked above to find out how to convert 'line' types.

I don't know what a "path path" is. Are you talking about "Add > Curve > Path"? Or using one of the 'Curve' types as a path? But, as mentioned above, and as far as I'm aware, it's not possible to convert any type of Curve into a Grease Pencil line because the two (Grease Pencil and Curves) fundamentally don't work, and are not represented, the same way in Blender - once you've created a Grease Pencil line it's effectively non-editable, notwithstanding the basic "Draw" and "Erase" tools, unless converted into a Curve.

What might be better is to describe what you're trying to achieve (what you're using Grease Pencil and Curves for) along with screenshots... it's kind of tricky to figure out what you're trying to do and reading what you've asked it looks like you might be trying to do something that isn't designed to work the way you want it to.

Slight Off-Topic: with regards to your solving your initial BSurfaces question; when you find a solution to a problem it's always a good idea to post a summary with respect to what you did to solve it. Not only does that help other people, it also completes the support process so questions don't remain unanswered.

[Zachary1234]

I use bsurfaces to interpolate between two edges to create a curved surface. However, bsurfaces only runs between two Grease Pencil Lines. When it comes to non-straight lines, Grease Pencil is only freehand. I need to add bezier to get the dual manipulator handle points to get my desired curve precisely correct, minus any freehand jitters. However then, I can't start bsurfaces between my bezier and a second line.

-So, how do I convert backwards from a bezier to a Grease Pencil line, if that is the only way to execute bsurfaces add <surface>?

-How can I do similarly between a straight line <path> already in place, to a bezier and then Grease Pencil, or to Grease Pencil directly?

[kat]

OK I see what you're trying to do and to be honest you are completely misunderstanding the tools, their capabilities and how to use them. Grease Pencil, as outlined in the documentation allows for the 'freehand drawing' ('sketching') of three different types of line;

• totally freehand (like using a pencil) using "Draw"
• a "Line" (like drawing a line against a ruler)
• and "Poly" (similar to 'join-the-dots' drawing)

Knowing this, what you are trying to do is not possible because you are converting a Grease Pencil line into a Curve to manipulate it into position then expecting to be able to convert that back to continue drawing. It doesn't work like that, at all, because (for the third time) Grease Pencil lines are not the same kind of editable Objects as normal Objects (like Curves and Mesh primitives).

There are two approaches you can use to do what you want, based on what it appears you are trying to do.

• 1) you either draw the item you're after in it's entirety; converting the final 'sketch' - using "Grease Pencil" sub-properties ("N") - into a "Path", "Bezier Curve" or "Polygon Curve" for further finite editing and manipulation; finally using the mesh tool on the completed Curve.
• 2) or you draw the 'sketch' line by line, converting, editing and manipulating each drawn stroke as you go (one at a time). Once you have the final collection of Curves you can then "Join" them together to form a final, singular, Curve based Object that's able to be edited further.

In both instances, once you have your Curves finalised you use the mesh tools to generate, edit and manipulate surfaces based on the type of Curve you're created and the number of vertex points it contains.

And if you need to add more Grease Pencil details you add another Layer, draw, convert and "Join" where appropriate. It's actually pretty simple and flexible procedure.

[Zachary1234]

-Yeah, that is right.  You can't so much alter anything to anything in place; you have to use a process of composition involving the numerics, <n> panel. Using one and two dimensions in comparison to other things, perspective at a time.

-Though, is this business of altering one edge into any form, and back to any form, on the cards for the future of Blender?  It would be the major thing differentiating it from a commercial product, and if included, even as an addon, would drastically make things faster. Like:

{-Path to bezier edit handles, with co-connected final end points in place.

-A series of path points into a single or series of corelative bezier points,  with co-connected final end points in place.

-The ability to do this on either a plane/nurbs surface edge in face construction, and to use the bsurfaces stuff or similar to correlate a combination of smooth nurbs surfaces on a face to directly create ripples.}

-Though, is there anything to easily create ripples on planes?

Moving along, though..

-If I have a composite path, with a series of dots throughout that I can <shift> select, When it comes to a number dots in a row anywhere, how do I select two endpoints, and also select all the dots along in between?

[kat]

There are a number of different selection options available in Blender when working with curves (using "Ctrl+NumPad Plus (+)" or "Ctrl+NumPad Minus (-)", including changing the behavior of node handles, just as there different ways to edit Curve nodes depending on what you're doing. There are also different ways to edit "Surfaces" constructed from Curves, depending on what you're doing. And as highlighted in previous posts above, Blender is quite capable of converting Curves into many different types of 'Object' including Meshes, it all just depends on what you're trying to do, ones understanding of the tools and how to actually do it once that is known - right now it seems you're button mashing and trying to brute-force Blender into submitting to your will because you can't get it to work the way you want it to 

For ripples you can generally physically model them or use some form of displacement modifier; either node based (render-time), or physical (actually affects the mesh). Also research 'Cloth' of 'Sea' simulation scripts and tools available in Blender as well.

Please do take the time to read through the documents linked to directly above, and the information previously posted, in relation to what you're doing, it will better your understanding of the tools and their capabilities with the added bonus of helping you use the correct words and terminology when asking for help - right now your posts take a considerable amount of precious time and effort to decode before they can be answered.