My apologies on coming up a bit slow on this but up until now I couldn’t really add in these type of trusses with a polygon floor because I didn’t have a viable algorithm for placing and sizing them.
With lumber and I-joists the algorithm is very simple, you essentially draw in the joists to reach the full extent of the floor in both X and Y and then boolean subtract away the stuff that doesn’t fit. A brute force approach to be sure but it works well enough for the purpose.
With individual trusses or open web joists the same technique doesn’t work, or at least not if you want realistic trusses, that are not all chopped up looking.
This new algorithm (only devised two days ago and further perfected last night) first finds all of the locations and sizes and then creates a new truss/joist for each new size encountered, reusing the sizes that have already been drawn as necessary (so as to eliminate extra calculations and processing). So no trimming or subtracting required but a slightly more complex system for determining what actually needs to be drawn. There may be a few flaws with it, only time will tell, it is too new to know if it is as fully robust as it needs to be, but I will continue to test it and try and break it.
Sometimes it takes a while to come upon the right solution to a difficult puzzle, but once I do development is usually rapid.
P.S.
This will now also allow me to add in regular MPC wood trusses into this plugin and effectively draw polygon floors with them, lots to be excited about.
P.P.S.
This wasn’t a new problem. I already ran into this brick wall with the floor trusses in the Truss plugin back in 2016. So technically I have been wrestling with this problem for almost eight years, but for most of those years I simply shelved the problem and moved on to something more pressing.
Currently these are defined by 13 parameters but I may need an additional four in order to specify a top chord extension and the bottom chord extension on both ends.
Spent some quality time cleaning up my code for the open web (Redbuilt) trusses/joists.
I’ve been thinking about the other three major steel joist types (KCS, LH, and DLH) however I can’t seem to find many detailed illustrations on how these are fabricated. If anyone can send me any schematics or diagrams on these standard SJI steel joists that would be very much appreciated.
I also need to finish adding in the 14" and 16" TriForce open joists.
Not the top two, I’ve been going to scores of different commercial jobs on a daily basis for 2 years now, and have never noticed them. But Clark Deitrick, them plain ol’ heavy gauge studs, for sure.
I can ask some of my colleagues though, they will probably know more about them.
Of those, only Clark Dietrich because it’s available in our region and is an approved product by governing agencies. Years ago we did an entire residential development using light-gauge steel framing (along with non-combustible roofing and wall envelope/cladding materials) because it was in a high fire hazard zone.
One specific limitation I wanted to bring to everyone’s attention with regards to TriForce Open Joists. They are currently only manufactured up to a maximum of 30 feet in length so that is the max. size I have included in the built-in component library.
So if your floor assembly is too large you will currently get something like this.
However, I may add in a non-standard size so that you can deal with floors that are 40+ feet or more, however please be aware that those are not realistic from the manufacturers standpoint.
Of course the other solution is to simply break a large floor like this into two separate floor assemblies (remove rim and sill plates as necessary).
P.S. I will add in a “custom” size that can be upwards of 60 feet but I like the idea given below of also providing a pop-up notification or warning. Let me see what I can do.
Could you have a pop-up notification or some other way to note that the joists exceed the manufacturer’s product standard specifications? This would be nice not only for the Triforce joists but all other manufacturers’ products with known limitations. Nothing worse than specifying something that doesn’t exist.
Hi Nathan, love your plugin. is there a plan to add top chord bearing to the OJ floor truss option in the floor plugin? I did like the option, especially as it allowed you to vary the depth, in the truss plugin
The open joist floor trusses that are currently provided are manufactured by TriForce (Barrette) and to my knowledge do not include an option for top chord bearing.
I have been giving MPC floor trusses some more thought since this is the last big floor system type that is not part of the plugin yet. The example I’ve shown below was created with the existing floor truss module of the Truss plugin. I created three separate assemblies to give me the geometry needed to end up with this final model (some manual editing required, but doable in about 1-2 minutes). The common trusses themselves are not too much trouble the algorithm already exists for their geometry and placement. However I will need to come up with some new logic for the gable (ladder) trusses shown:
Rather than insert a fictitious joist size that does not actually exist I decided to insert two short joist products back to back. This seems to be the typical way to handle large span floors with this product (similar examples are given in the product literature). This update was also by customer request.
The update to the SUBTRACT_JOIST feature is a critical update and I highly recommend updating to this latest version if you are using that functionality. Since the boolean subtraction of the joists happens before the final floor assembly is created I had to account for the pre-transformation of the joist geometry and include this within the subtraction method.
Currently the split will be even so that the joists are the same product length, however in some situations as shown in the second image one may want to line up the split line, I am thinking about how best to handle that.
