search

vilemduha / blendercam

Automatically exported from code.google.com/p/blendercam
GNU General Public License v3.0
469 stars 118 forks source link

T-bone, Key, or other such inside corner strategy #51

Closed dynamodan closed 8 years ago

dynamodan commented 8 years ago

This feature may already exist, but I can't find it. When doing profile cutout, what is the chance of being able to cut into the inside corners to avoid leaving a radius such as described here:

http://blog.inventables.com/2014/06/learn-about-milling-inside-corner.html

ghost commented 8 years ago

I use one of the blendercam tools called overcut to modify the curve. I then use the new curve generated for the profile cutout.

There is a little blurb about it in the wiki: https://github.com/vilemnovak/blendercam/wiki/Blendercam-Tools#add-overcuts

see: https://github.com/vilemnovak/blendercam/wiki/Blendercam-Tools#view-tool-shelf too get to the Blender CAM tools in the Blender Tool shelf.

dynamodan commented 8 years ago

That is excellent! Thanks for pointing it out to me. I had a feeling it was in there someplace!

vilemduha commented 8 years ago

Well, at least I know the interface should be fixed :)so that users actually see the features .

dynamodan commented 8 years ago

The interface is good. I should have read the wiki before asking. ;) A few things to note: 1. Without "Outer polygons" checked, nothing seems to happen. I'm not sure what this is supposed to do, beyond the obvious. (The Invert checkbox works nice.) 2. The overcuts are always "dog-bone" and it would be nice for T-bone in cases of square tabbing, but maybe it's too difficult. (I'm not especially good with geometric calculations or I would fork this myself, and add some settings to do this.)

ghost commented 8 years ago

T-bone case can be added to the master branch. I have a version working on my machine that allows T-bone orientated either on x or y axis. I will generate a pull request for Vilem to review.

dynamodan commented 8 years ago

This is exciting. I'm going to reopen this issue for visibility as others may be interested in this too.

vilemduha commented 8 years ago

nfz - if you have it working just commit it ;) no need for pull requests.

ghost commented 8 years ago

I decided to make the modified version that I use as a separate new overcut operator. The main reason for this is it does work a little differently than the old one so didn't want to confuse people.

Here is what it looks like: overcut_db If there is only one curve then the operator will work even if "include outer curve" is disabled since there is only one curve to work with. "include outer curve" is only useful when there are curves inside. overcut_dbno

T-bone overcuts: overcut_tb

T-bone overcuts on the other edge with inverse: overcut_tbo

T-bone overcuts without inverse: overcut_tboi

T-bone overcuts on the other edge without inverse: overcut_tbon

There is also using overcuts on opposite edges: overcut_oe

Opposite edges with other edge: overcut_oeo

ghost commented 8 years ago

I pushed this to my overcutb branch: https://github.com/nfz/blendercam/tree/overcutb

vilemduha commented 8 years ago

Jeff, this looks very good to me, I don't have much time to go through the code now, but the results are just what this should look like ;) So feel free to commit also to master.

vilemduha commented 8 years ago

also, when you already had work with those images, they could go to wiki too?

ghost commented 8 years ago

The code didn't change much, I just re-organized it a bit. The capability for T-bone was already there in the original code, it just had to be exposed ;).

When I update master I will update the wiki.

dynamodan commented 8 years ago

Guys, this is fantastic. It works perfectly on a tabbed "plywood cube" outline that I made using Addam's paper model export addon, that I forked, and added plywood-tab output:

https://github.com/dynamodan/Export-Paper-Model-from-Blender

Screenshot of T-Bone working: blender_100

Now for some more complicated, more angular stuff. ;)

ghost commented 8 years ago

Cool, I am going to give your fork a try. I need that for a project coming up, good timing :).

There are some issues with some shapes that I am still figuring out how to solve which is one of the reasons why this has not gone into master yet. If you come across any strange results please post pics.

dynamodan commented 8 years ago

Actually yes, I did discover an issue, but it's in a mode that I wasn't going to use at least for this particular object. It could be a problem with shapes having odd angles besides 90. It seems like the function is simply alternating, because when it encounters a condition where it overcuts an "odd" corner, the remaining corners are cut opposite, as in this screenshot. blender_101 It seems like the logic for determining overcut direction for T-Bone should look at the lengths of the lines that are either side of a given point, and choose to cut into the longer one rather than simply alternating. Not sure if that makes sense.

ghost commented 8 years ago

You are correct in that the algorithm I used is simply alternating the edge when an inside corner is found and fails when there is an odd number. Length alone does not always work either. The two combined may cover most scenarios. I am looking at some other cam software that have this functionality and learning how they deal with it.

ghost commented 8 years ago

One method that I am trying right now counts turns instead of edges and seems to cover all the problem areas I have encountered.

ghost commented 8 years ago

Yep, the turn method works really well. I will update my github branch with this method.

ghost commented 8 years ago

Nope, found more fail cases with the turn method. Its better than the first two methods but there are some simple situations where it fails. Back to the drawing board.

ghost commented 8 years ago

Forgot about this branch until I needed it for a job. Its now pushed to master. There are still a few cases where T-bone is not correct and I need to put in some more rules to fix these when I figure them out :).

For most shapes and tabs, T-bone works but if you find a situation that does not work please post a screen shot.