I'm testing constraints with an extrusion along a path to create a door frame. I want to constrain the height and width and have them as variables but when I attempt to 'flex' the variables the results are inconsistent and wrong. I've created the constraints by constraining the path before extruding as I can't see a way to do it afterwards. The height constraint seems to work but the width is giving odd results. Example attachedperforatorNamedViewtest.dgn
Hi Duncan, I am going to look at the file and get back to you. in general, once you used some geometry for a feature, you can hold-right click on its gliphh and select "Show input element". this will make the path or pofile visible on the screen for editing. You can then use display sets to isolate for easier editing.
Product Manager, MicroStation
Bentley Systems intl
i had a very quick look at the file and the unexpected behaviours you are seeing when changing variables' values is due to the profile not being well constrained. you should always try to draw your profiles as closed shapes and check their DOF (degrees of freedom) is 0/. This means that there is only one possible solution for any change of the parameters. This somethimes may be tricky when the profile is complex it is worth getting used to do so.
I have attached a quick edit of your file, let me know if you need more help with this!
Thanks for the prompt response Marco. i'm still having problems with this file (your amended version). I changed the width value to 2 metres and the frame does not respond properly. It just changes so some weird thing. I understand the need to set proper constraints but I would have thought that if I constrained the path for an extrusion and the modified the value the extruded geometry should follow?
mmm...I might have misunderstood then. There was something odd with the extrusion profile: I couldn't isolate or select it or check/show its constraints, so i have re-created it, constrained it and replaced it as an input element for the extrusion along (I have shifted the feature inadvertedly, please move it back where it is supposed to be )...let me know if it is any better now.
That seems to work as expected. I created the extrusion using the Extrude along tool in the solids tab using a simple smartline path so I don't know what I could have done to upset it. I'm a little concerned that this is a bit to easy to break at the moment.