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Intersect and Divide Causing Wireframe Issue In OpenStudio Plugin

asked 2016-03-09 22:20:55 -0500

coastalconcepts's avatar

A lot of people will have come across the wireframe mode issue that comes from using the "Intersect and Divide" function of the surface matching tool - there is useful information on it here and here.

However, I can't seem to beat this one.

Basically the model gets stuck in wireframe mode if I try to use the Intersect and Divide function to allow me to complete surface matching. From this point on all subsequent models that I try to load get stuck in wireframe mode too (even if they were loading fine before). I can fix this by reinstalling OpenStudio 1.10 and reload an old model but as soon as I Intersect and Divide the same issue occurs. Here's what I have tried:

  • Extensions > OpenStudio User Scripts > Reports > OSM Diagnostic Script
  • Reinstalling OpenStudio
  • Full System Reboot
  • Running the "Surface Matching Measure" as described here
  • Have been over the model with a fine tooth comb to ensure all faces match nicely
  • Went through the instructions listed here to diagnose the problem via the ruby console but ended up with thousands of faces being listed as having errors - at which point I may as well just re-model the whole thing.
  • Began manually dividing surfaces within each zone before I thought "this is the 21st century, perhaps someone on the interwebs can help me"

I could re-model the whole thing but without understanding why this is happening I would be asking to face the same issue again right?

Here is the file:

Any suggestions/help much appreciated but please see what I have already tried (above).

Using Sketchup Pro 2016 Windows 7 OpenStudio 1.10 Energy Plus updated to latest version

Thanks in advance for any help

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FYI - I tried to run the surface matching measure, and saw that it crashed. I've linked this thread to the open issue about this.

David Goldwasser's avatar David Goldwasser  ( 2016-03-10 11:39:35 -0500 )edit

Do you have any hunches that I could try?

coastalconcepts's avatar coastalconcepts  ( 2016-03-10 13:21:07 -0500 )edit

Has anyone considered that this is caused by the intersect algorithm causing existing surfaces to turn into windows and doors? I just ran the intersect/divide tool and sections of internal walls (in between zones) got reformatted into windows and doors when they shouldn't have been...

coastalconcepts's avatar coastalconcepts  ( 2016-03-27 23:15:19 -0500 )edit

2 Answers

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answered 2016-03-10 17:40:58 -0500

coastalconcepts's avatar


I managed to get the model to intersect and divide after an extensive series of trial and error.

I have found in the past that zones within other zones (IE zones that are completely surrounded by another zone) can cause problems and don't really seem to be recognized by OpenStudio. Within the above model was a small stairwell zone which was essentially encapsulated by a larger zone.

When I extended the stairwell zone so that one face was outside of the surrounding zone the intersect/divide tool seemed to work seamlessly.

This may not be the only factor as I tried just about everything else up to this point but it was the first change I made that got Intersect/Divide to work properly.

Some other things that I've learned are important in this instance:

  • Ensure all faces on the same plane are perfectly aligned and not out by 1mm or so
  • Ensure all faces are appropriately assigned (floors are not represented as ceilings etc). You can fix this in SU by right clicking the face > OpenStudio > select the appropriate face type.

Thanks for everyone who contributed.

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@coastalconcepts ,Thank you very much for your useful info. I had some surrounded zones in my 1st floor and I wanted to draw an interior doors for them but when I wanted to intersect and match my model it changed to wireframe. after reading your answer I did not draw interior doors for those surrounded zones . And now my model works!

4Designer's avatar 4Designer  ( 2016-04-12 04:10:58 -0500 )edit

answered 2016-03-10 10:14:37 -0500

Adam Hilton's avatar

I may not be the most qualified to answer this, but I used to run in to this problem all the time.

I think it has to do with re-entrant corners where one surfaces intersecting to make the corner is co-planer with a surface of another thermal zone. I don't know, it's hard to see the exact correlation, someone else is better to speak to about that. What has helped me though, is to subdivide the problem surface by simply drawing lines so that the subdivided surfaces are four sided.

This is not a good example by any stretch since this geometry will intersect fine in some situations, but it should get the point across. This is a thermal zone on the ground floor that that spaces on all sides of it and an additional one above it.

image description

When I try to intersect the model drawn like this I get the 'wire frame problem'. And surfaces are created that can't be drawn by sketchup.

Now, I add two lines that that takes my ceiling from 1 surfaces to 3 surfaces resulting in the following. image description

Now I'm able to intersect and surface match the model with no problems. I'm not able to explain why this is, but I know that on any occasion where I've had problems intersecting the model, this has been a solution that has worked for me.

The problem surface(s) can be pretty easily identified by either running the diagnostic script or if you reload the model that just failed an intersection the ruby terminal will typically pop up with a list of the surfaces that were impossible to draw.

Hope that helps!

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This works for the non convex faces issue but, unless those lines correspond with adjacent zone faces I can't see how they make a difference. Can anyone else explain this?

Thanks for the feedback adhilton25

coastalconcepts's avatar coastalconcepts  ( 2016-03-10 13:10:14 -0500 )edit

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Asked: 2016-03-09 22:20:55 -0500

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Last updated: Mar 10 '16