offsetting an edge?

Support Modeling
#1

I am still a beginner to blender.

I would like to increase my skill at creating sharp edges with the subsurf modifier on. It seems that the way to go is to create an extra edge loop that is very close to the edge you want sharp. I think I have heard it called beveling.

I also use Rhino which has an offset feature. You select a border or line and then you can create another border or line that is offset by an exact amount. So, if I want an extra edge loop, I can offset one that is exactly .010" all the way around from the original edge loop.

Is there a way to create an offset edge loop like that in blender?

Thanks,
Dave

#2

For sharped edges with subsurf go into edit mode, assuming you’re not in that mode already, press N to bring up the Transform Properties box, select the edges you want sharpened, and increase the Crease W value until you are satisfied.

#3

You can use edge sharpening, but for the exact tool you were asking about that is ctrl r and to enter an exact amount just start typing after you get your edge loop on screen and before committing.

The manual entry is here.

http://wiki.blender.org/index.php/Doc:Manual/Modeling/Meshes/Edge_Tools

#4

Thanks Krisnack. Using the crease function worked nicely at a crease value of 1.000. Using it to create a tight, rounded bevel required a lower crease value and a very high subsurf value. Otherwise it was too rounded.

Richard,
Your method sort of works like I want on simple objects. I only seem to be able to type in a percentage or drag to place the new edges. On more complex objects, I do not get complete edge loops with the ctrl+r function.

I was looking at a modo tutorial, which shows a bevel function that is pretty cool. After choosing the edges you want to bevel, you adjust it by percent, or by a measurement value, or by dragging and clicking. The program then inserts a set of edges that are offset from the chosen edge on both sides along the object. With subsurf (sub-d) on it creates a tight curved beveled edge. This could be a pretty neat feature in blender. It would allow crisp edges with very low polygon counts.

I think it is sort of like what the bevel modifier does in blender, except in modo you can choose the exact edges you want to modify and the original edges are not deleted after the operation.

Thanks,
Dave

#5

Well yeah, that is the thing with the sharp method. You have to use a high sub surf count which defeats the purpose and most modelers who use subsurf for more than just a simple object use polyflow rather than edge sharpness.

Sorry - I thought you wanted to add a loop.

Sounds like what you are looking for is a good bevel (offset) tool that does not exist in Blender and will not for some time it looks like. You can use e to extrude your selected edges/faces. But after that you’ll have to use scale (s) or (alt s) or drag the points by hand.

There are no real good interactive solutions for this and everything is a workaround in Blender. Your thoughts on the matter are not new. Depending on what you want to do you can use the Solidify Selection script as an alternative but it is a suck-ass alternative to a good offset tool in Blender which is a horrible oversight.

I work around it with other work flows I have developed as a result. But in many cases it adds a lot of time to my modeling tasks.

Good luck with your modeling. I suggest reading over the manual. It has many great features you’ll not know about unless you do. Combined, they almost make up for not having an offset tool. And in many cases surpass other work flows. So it is a trade off.

#6

Richard,

I will look into the Solidify Selection script. I am trying to learn the “extrude - esc - scale” trick for making inset loops. But, it only works on simple shapes, and I have to do all kinds of cleanup to make the subsurfed object look right.

I hope that the 2.5 rewrite makes it easier for developers to add some precision modeling features. I like to measure things. I do when I draw with a pencil or when I paint in oils.

I am interested in modeling hard surfaced subsurf models, like cars, planes, boats, architecture, etc. For now, I think my modeling toolset will have to include Rhino and Modo. I keep trying to use Blender, too. I am really excited about Luxrender integration with the new interface.

BTW, Modo has another cool tool where you choose some points and drag them onto a background object, at which point they conform to the shape of the background object. Sort of like what retopo did, I think. Is retopo working in 2.5?

Thanks,
Dave

#7

All it needs is someone who can write python scripts and the interest to do so.

BTW, Modo has another cool tool where you choose some points and drag them onto a background object, at which point they conform to the shape of the background object. Sort of like what retopo did, I think. Is retopo working in 2.5?

Blender snap set to surface snapping and with projection on. To see a demonstration of this retolpologising a mesh look at http://www.blendercookie.com/2010/08/30/retopology-and-normal/

#8

Very cool!

Thanks,
Dave

#9

i have built this into CADtools script, among other missing features :slight_smile: , but only 2.49 now :frowning:

#10

migius,

What you are doing with CADtools is huge!! I will study your webpage on this project. It looks very comprehensive.

Have you had any experience with Rhino? The interface is very easy to learn and use. I was making complex parts within minutes of first using it.

pg. 18, Rhino version 3, User’s Guide:
Rhino is a "command driven’ program. Actions are activated by commands. Commands are accessed by ‘typing’ the command at the prompt, through the ‘menus’, or the ‘toolbar’. The choice is yours and there is no preference for one method over another.

I really like this structure. Whichever way you choose a command, the command line responds, offers subcommands which relate to the main command, and allows you to enter data - like ‘.x’ for x constraint, or numerical data. There are several clear ways to find a command. And Rhino’s command line responds with comments on how the program is interpreting your inputs. I hope in your CADtools for Blender 2.5 you add a command line for clearly inputting values. Scaling, moving, mirroring, rotating commands all let you input precise data. The orient command is also very powerful.

For an inset function in Blender you could have a command box for inputting the distance by percent and one for inputting the distance by measured value. Or the user could click and drag the placement of the inset edges.

I am going to try Modo 401 to see how easy it is to model things precisely. I have seen some amazing work done with Modo. One of my favorite digital artists is Cristóbal Vila, and he is using Modo. His level of care and detail is fanatical!

http://www.etereaestudios.com/index.html

Picasso said, ‘good artists copy, great artist steal.’

Open source projects should be stealing what works from other programs.

Thanks,
Dave

#11

hi dfro, thanks for suggestions, i haven’t opportunity to work with Rhino, but it is on my try_out list. Actually I am still very busy with implementation of my own work-flow concepts, so maybe after that i will look for alternatives.

For an inset function in Blender you could have a command box for inputting the distance by percent and one for inputting the distance by measured value. Or the user could click and drag the placement of the inset edges.
this is already implemented in CADtools, though not so obvious (still no manual released):
iirc all numeric input fields in Blender accept math expressions (python syntax).
Additionally to this, CADtools input fields support mixed decimal/imperial units and evaluate any python expressions.
CADtools project is by far not finished, i would say there are about 20% of my ideas implemented now.

#12

migius,

I would like to humbly offer a few ideas on getting paid.

If you want to make money doing this, I think you should put an automated donate button on your site that makes it very easy for people to contribute. You might want to check out how the guys at Ardour (digital audio recording/editing software) are trying to get paid. They ask professionals that are using Ardour to contribute a monthly donation to keep development continuing. They also have a pledge area for functions that people want. As the pledge amount increases, the developers get more excited about adding the funtion. There is also a graph that shows whether the main developer is making a decent living this month. It really gets the point across to the professionals using the software.

I am sure there are some other standard ways that people are getting their FOSS projects funded. Google Summer of Code?

I think the “e-mail for the scripts” idea is a bottle neck. The world will love you for openly sharing these tools. You will be the Linus Torvalds of Blender CAD functionality. I think what you are doing is so important to Blender that you should be included on their team (that means you should get some money from the Blender Foundation).

Start a forum where we can all rant about the CAD functions we want added or improved. For example, trying to use Blender’s snap tool to accurately position an object drives me crazy. On the forum have a section about what human factors, ergonomics, functionality, etc should be copied from other programs - like Rhino and Modo.

Make the website look more interesting. Give us screen shots and videos. Draw us into the excitement of what you are doing next. Have a CADtools gallery.

Tell others what you are doing. Have you told Allan Brito at www.blender3darchitect.com about your project? I am sure he would love to do a write-up on your progress.

Put some advertising on your site. Create some members only tutorials on how to use the CADtools like at Blender Cookie.

It seems to me that getting paid as a developer in FOSS projects means doing a lot more that writing great code - you have to build a community of people that are excited about what you are doing. I know I am excited about what you are doing.

Thanks,
Dave

CADtools - alpha release (for 2.49)
#13

I was able to follow Jonathan’s tutorial and draw/extrude new vertices onto an object. But, I was not able to project a set of vertices onto an object so that they conform to the background object’s shape. This Modo tutorial shows what I am talking about, where one cylinder has its bottom row of vertices projected onto another surface:

http://www.luxology.com/tv/training/view.aspx?id=506

Can this be done in Blender?

Thanks,
Dave

#14

hi Dave,
here the answers to your post:
http://blenderartists.org/forum/showthread.php?p=1696741#post1696741