No, REALLY complex geometry modeling

[Anonymous]

I think I'm pushing the boundaries of what FormIt can do in terms of complex modeling. I am working on a bar which some crazy blends and transitions. From the documentation it is a seemingly simple for until you start finding the transitions from concave to convex faces. I had a first attempt in Revit and got it fairly close. After some changes were requested from the client we found that making these changes were not only inefficient in the mass family editor in revit but that Revit refused to recreate the geometry, even when trying to loft.

I've been struggling with this in FormIT for quite some time now. I'm trying to recreate the profiles to perform a loft, which I'm finding FormIt will do and Revit will not. I wanted to start this post for 2 reasons:

1) Begin a discussion on complex geometry modeling in FormIT and ping the community for ideas on how to handle this geometry.

2) To report some of my experiences when working on this.

I'm posting both the RFA after I tried to make modifications to my original family as well as the changes I am trying to perform and the axm file. Below I will describe what I've done so far and what my plan is going forward.

Currently the model is in a stripped down version. I began with an export from the RFA. I did this because I found drawing splines on a single workplane very difficult in FormIt. I may just not know the proper workflow (this is literally my first week working in FormIT). It seemed that I was always having to delete and redo profiles because a vertes would bounce way out to some point somewhere else. After getting the export from Revit I began stripping out the vertical profiles so that I could work with only the horizontal profiles. I still have some stripping to do but the model is at a point where I can begin making the modifications requested by the client. I am using a combination of both redrawing lines and dragging vertices. Dragging vertices seems to be very cumbersome at this scale. Some of these points are being move less than 1/2" and FormIt doesn't seem to like small movements like that; the vertex stays snapped to the original location. I also seem to have difficulty with keeping vertices locked to the horizontal plane so they don't snap to locations above or below their original plane.

I am very interested in using FormIt in future projects like this. Currently it seems to work better than Revit (where I run into the same issues with creating the profiles AND the loft won't form) so I'm willing to run with it as a complex modeling tool. However, I also get the feeling that FormIt maybe wasn't built for modeling like this. 

Any thoughts or insights from the community on their experiences with complex geometry modeling? 

Thanks for your time and I look forward to reading your thoughts. Have a great day!

pS: Please note that the redlines are clearly done by someone who has never taken a drafting course in their life and do not understand how elevation and plans affect each other.

pPS: The forum wouldn't let me upload the AXM file. You can find it here: https://delineations.sharefile.com/d-s7444c07055d4c398

[Anonymous]

So my first question while reconstructing and modifying these loft profiles is what we think the preferred method for drawing the profiles should be. Lines, Arcs or splines? You can't edit Splines [yet] nor can you edit arcs. Will line segments give you a tine of profile lines in the surfaces when brought back into Revit? Thoughts?

[josh.goldstein]

Hi rkitecsure,

Thanks for writing in and starting the conversation! Thanks also for sharing the models and PDF.

I think FormIt is up to the task (more below), but have you considered using Dynamo for this? You could hook up the horizontal lines in Revit to cross-section inputs in a Dynamo Loft component. Or, you could parametrically draw the section and rail curves in Dynamo and use a Sweep component to generate the form parametrically. Dynamo Studio also has direct manipulation of points, so you could construct the curves using a few points in space, then select them and move them in real time, and the form will respond accordingly - this way, if the client has more changes, it's much easier to adjust the form without rebuilding it. See the Direct Manipulation part in the Dynamo Primer here if you want more info: http://dynamoprimer.com/en/02_Hello-Dynamo/2-6_the_quick_start_guide.html

Ok, back to FormIt. Based on your comments, I have a few suggestions. This first set assumes you want to use the horizontal curves and Loft between them:

1. Eliminate all the vertical and angled lines, leaving just the horizontal curves as you suggested

2. When editing the Group, you can right-click into space to bring up the context menu, and hit the icon that looks like a 3D axis on the far right, this is the Set Axes tool. This allows you to set the origin and workplane for the Group. Put the axes origin on the horizontal line you want to adjust. This will move the horizontal plane to that curve and will ensure that when you have a vertex or segment that you want to move, it won't go below the Group plane. You'll need to have the Grid turned on (shortcut DG) to avoid snapping to geometry below the plane.

3. When moving vertices or segments a tiny amount, you can hit Tab to bring up the dimension box and specify a more accurate dimension than you'd be able to get by moving your cursor. Using trick #2, you can also set the axes temporarily to be perpendicular or parallel with a particular segment, so you know you're moving it in the right direction, as well as the right distance.

4. Once you've cleaned up the vertical lines (#1), if you hover over a segment of one of the remaining horizontal lines, and hit Tab, FormIt will pre-select the rest of the segments attached. At this point, you can click on the curve to add the entire curve to the selection. Use this trick once you've started the Loft tool, so you can select each complete curve much easier, without clicking every segment individually. So: enter the Loft tool, hover over the first segment, hit Tab, click the curve to get everything attached, and click next on Loft, which will continue asking you to feed it curves (repeat this method) until you've selected all horizontal curves.

Another idea is to use Sweep, but this will require a lot more deleting and rebuilding of the model you sent:

1. You'll have to draw the vertical "profile" curves - probably a profile for each end of the bar, and one for the front portion, since the sections are different. You may also need to sweep other parts separately, like the area above the counter. You can use a mix of Splines and Arcs, and you can set the Workplane per #2 above to control on which plane you're drawing the curves.

2. You'll want to eliminate all horizontal curves, except for one clean curve that can act as a "path" to drive the sweep for each section. Note that our tool sweeps only using 1 "path"... it looks like the bar has the same path on top and bottom, so this might be fine.

3. You should be able to sweep each section individually given a clean profile and path curve. There might be some cleanup where the sweep surfaces meet.

Thanks for the comments about editing Splines (and other curves) after the fact. We agree this would be great and are working on it.

FormIt automatically facets Splines and Arcs to the same degree, so it's really your choice which you want to use - neither should impact performance much more than the other. By sheer functionality, I think the Spline tool might be your best friend here.

By the way, I noticed this file is quite slow to navigate in the current FormIt app (sorry), but the good news is, our next release will have significant performance improvements that make this file much easier to work with!

Hope this helps. Let me know if I can clarify anything!

[Anonymous]

Josh, thanks for the reply. I did try and use the dynamo concept but upon testing the profiles which would be used to create the loft to begin with Revit failed to create the geometry every time. At least with FormIt the geometry is forming. Also with the horizontal profiles, the number of curves and transitions from one profile to another are so minute and so complex that I wasn't able to put logistics to how many profiles I would end up needing to drive the form that I was just ready to redraw and create geometry!

I can't really use Tab because I don't know the exact dimension. This is purely eyeballing which the snap features makes fairly prohibitive (even when snapping is off xD)

I figured out the use of the axes to help aid locking vertices to a horizontal plane. I'll have to work that in with turning the grid on as well. 

The original geometry was created using sweeps. The forms didn't want to join very well in Revit. I may need to try sweeping in FormIt to see what happens. I think I was going to try that but my attempt to import the DWG that I had of the profile failed. Can't remember what the error was, I just moved on. My fear though is that after creating the sweep, I wouldn't be able to modify the geometry enough to create the carved portions. and blends to different profiles. I may give it another shot though.

Thanks for your feedback. I look forward to sharing the final product. 

.Carl

[Anonymous]

Also, not that you want to spend your evening watching a stranger work, but I'm live streaming my modeling tonight in case you want to come in and school me: https://www.facebook.com/cre8iveThings/videos/1450953048250582/?pnref=story

I also wanted to mention that the Tab key; sometimes it selects a segment, most of the time it selects the entire imported geometry. Sometimes it works for me though! Also, the grid tip will be a time saver. Thanks!

[josh.goldstein]

Hi Carl,

Thanks for the invite to the livestream! I probably can't come in and school you tonight, but I'll offer you a few more thoughts in response to your new comments:

- My trick with the Tab key for dimensions is, as long as the temporary dimension is on screen, you can continue to hit Tab repeatedly to your heart's content. So, you can try 1/8", then 1/4", then 3/8", etc. until it looks right. I've found it's a nice way to have accuracy AND get the eyeball feel too.

- DWG import is coming! In the meantime, if the DWG linework is coming from Revit, you can export to SAT from Revit, and import the SAT into FormIt.

- As for Tab selecting the entire geometry, this is where you'll need to make sure none of the vertical lines are connecting the horizontal lines together. That's why I listed it first in my recommendations - you really need to separate things out to make sure the Tab trick works as expected.

[Anonymous]

Thanks again Josh. I'm getting there in terms of workflow. Is there a trick to making sure that with the Grid visible, when drawing a line, I can snap to the intersection of the grid plane and an intersecting line? I'm having issues and it seems to be inconsistent. I feel like I'm missing something. See video below for example:

http://gibsonhh.info:8081/revit/video/2017-01-24_21-41-59.mp4

[josh.goldstein]

Yeah, I see what you're trying to do there. Unfortunately, I don't think you can snap to the actual grid plane (feature enhancement you'd like to see?), but you can try this:

- When inferencing to one of the vertical lines, you can hold shift, and you should be able to lock to that line, and then inference back to the elevation point you've started from to ensure the second point is along the same plane as the first, using the line as a guide.

Let me know if that works?

[Anonymous]

It is possible, it just seems very difficult to replicate it doing it: http://gibsonhh.info:8081/revit/video/FormIt_2017-01-25_00-31-41.png

[Anonymous]

Well, after too much time spent the only consolation I have for this project is that I did tell them it would take too long for the amount of budget we had in the project. After cleaning up much of the geometry and doing a dry run with the lofts, mirroring and bringing it into revit I was unfortunately left with this:

I believe the messiness of the imported geometry is a result of the same issue which was causing the creation of the geometry to fail inside of Revit which is extremely poor manipulation of the loft profiles on my part. Thanks for the help. I'll let you know if I end up finishing this later on.