ModelIT Remains a Complete Disaster for Buildings not Composed of Perpendicular Lines

[R Tibenham]

I have recently been involved with modelling a cylindrical building and am currently modelling a building composed of several wings at acute angle from one another.

Anticipating the cyclical building to be geometrically challenging, I used the Sketchup plugin to model the geometry for import into ModelIT, eventually being able to create a complete model of 'clean' geometry.

Upon import into ModelIT however, the software ruined the previously clean geometry, adding corruptions such as missing elements, erroneous surfaces and so on. The process, which took over a week of modelling time, also incurred a painful repetitive strain injury.

On the much simpler scheme I am having similar, yet lesser problems.

ModelIT remains incapable of producing or importing geometry composed of non-perpendicular surfaces in many cases, yet is required in order to progress the modelling process further.

Is there any likelihood of a 'fit for purpose' modelling package in the future?

[farahghanem]

I am sure the importing feature needs a lot of work and the future releases will continue to improve on that. Personally I have never used SketchUp to build geometry and then import into IES, as I find it less "risky" to just use ModelIT from the start.

For cylindrical geometry and acute angled wings, you can try using the arc drawing tool or snapping to multiple nodes on the dxf. The later would probably give you a good approximation to the cylindrical shape, which would be somewhat acceptable in compliance modeling.

I personally think some practice using the arc drawing tool, or drawing circles/cylinders/spheres and then cutting out the portions you do not need would save you time and effort in dealing with import errors.

[R Tibenham]

>farahghanem

Hi there -thanks for the comments. I do hope that future releases do continue to improve the modelling element of the software, as has generally be the case for the past few years.

I have been modelling in IES for 6 years now on an almost daily basis, so I have a good understanding of the software. I am very procedural in my modelling approach in order to avoid problematic issues. I did actually start modelling in ModelIT to establish some of the basic geometry, but moved over to Sketchup when errors started to become a major problem.

One of the principal errors being encountered is the inability of ModelIT to construct error-free geometry involving non-perpendicular lines. Using the slice tool to partition an error-free, non-perpendicular, extruded shape with planer edges for instance will frequently lead to surfaces being deleted (something which is not always apparent when modelling in wire frame). The same issue is true when combining similar shapes. Even with very tight control over what the user is doing, moving 'off-grid' is sure to lead to problems.

I think the general frustration is that the geometries being dealt with are not complex -they fairly simple shapes with planar surfaces, not complex organic surfaces. In this regard, the geometry construction elements of the software seems well out of date, yet it is the conduit that must be used to enter geographical information for further simulation. Its a pity, because once beyond this stage, Apache and other powerful software modules can handle more complex geometries -the problem lies in the ability to assemble it -which seems a simple challenge compared to complex thermo-dynamic simulations.

[farahghanem]

I do not have nearly as much as your experience, so I would guess I have yet to encounter such geometric problems. Perhaps you can share some screen-shots to illustrate how and when an error would occur?

[Complex Potential]

I know what Tibenham is talking about and I'd agree that ModelIT is probably one of the least robust and least forgiving geometry building packages I've ever seen. In its defence, most of the time I manage to trace the cause of missing surfaces and other seemingly random errors to almost imperceptible mis-snaps, some of which are not even connected to the zone.

In my opinion, what ModelIT really needs is a more intelligent snap system that can dynamically correct for the human element. It is really quite frustrating to spend 5 hours searching for the cause of a missing surface only to eventually track it to a vertex that is sitting 0.0001m away from a model end point.

[R Tibenham]

I'm inclined to agree a fair degree that the precision of snaps has a good deal to do with the problems that occur. Compared to Autocad for instance, snaps do seem a lot less reliable. The software could help matters out by providing alerts that adjacencies are unmatched or surfaces are missing - its not obvious when using the wireframe model. Some issues only come to light when assigning materials.

That said, I'm not sure to what extent the software's ability (or inability) to deal with triangulated forms comes into play. Even when slicing up forms drawn using the cylinder tool, the software can easily run into issues where more than a handful of vertices are involved. As mentioned, I had a set of clean geometry when exporting from Sketchup, yet when imported it still managed to mess it up.

Either way, it can be seriously frustrating. Its a pity the modelling element of the software is so primitive compared to the rest.

farahghanem; I'm a bit too busy to be posting screen shots at the moment. If you look into assembling some 'off-grid' geometry, I'm sure you'll soon run into the sorts of problems we're talking about.