Hi there! I am quite new to grasshopper and am having trouble figuring out why this triangular surface does not extrude to the same length of the blue box. I would like the extrusion to be the same length as the blue box so that upon changing the diameter they will both be the same length.
Thank you!
ParametricModel2_rot.gh (30.9 KB)
your uploaded GH definition doesn’t include the extruded triangle…
I’m sorry I don’t understand. The attached file has the extruded triangle as shown in the screenshot.
this is what i’m seeing when opening your gh file
maybe you forgot to save and you sent an old version of your GH file
@adel.albloushi when I open the file from @tuenip I see what his screenshot shows.
@tuenip you are feeding a line (edge from the rectangular brep, hi-lighted in yellow here) into the Direction input of the Extrude component. This input is expecting a Vector. If you hover your mouse over the Direction input, you will see that it is being converted to a unit vector (-1,0,0).
You can get the result you’re expecting by converting the line to a vector with the same amplitude as the length of this line.
-Kevin
oh, i think we found a new bug
left is Rh8.5, right is Rh7.36
@tuenip sorry about that, it didn’t occur to me to open the gh file in Rhino 7
in any case, for educational purposes, here’s another way doing the exact same thing as @kev.r
Hi Adel -
I’d say it’s a know limitation.
You can’t rely on the list order when deconstructing a Brep.
I reduced the OP’s file to check what was going on here.
In Rhino 8, the Cap Holes component throws an error, which it doesn’t in Rhino 7.
When you select the curves in the red group, these get selected in Rhino 7:
In Rhino 8, you get these:
To make sure that the required output is used downstream, you need to come up with rules to pick the correct items from the list.
ShapeDiver documented this when users went from Rhino 5 to Rhino 6. See “Case 2: Deconstruct Brep” → Optimizing Grasshopper Definitions Explained!
-wim
i’ve run into this problem as i was creating my own c# script. the particular case there was that i wanted to get a particular edge after a rail revolve… Long story short, i’m suspecting that the brep topology ordering isn’t reliant on a random number generator, and it would be nice to know the system behind the ordering - at least in some cases
