Roof by Extrusion grows down?

[dbaldacchino]

I didn't realize, but roofs by extrusion grown downwards (like a floor) instead of up, like a roof by extrusion. This seems inconsistent to me and I think it whould grow upwards. What's your take?

[luigi]

There is a reason why the footprint grows upwards...and it took a while, and now I agree with it growing upward (I can now use the Top of Steel level for a roof)...and yes, I was a bit frustrated when I noticed the extrusion behaves opposite...also a bit ashamed when I was showing somebody how to do it by extrusion and told him that it would grow upward....but it didn't it grew downward :s

Got my vote...it's too inconsistent

I didn't realize, but roofs by extrusion grown downwards (like a floor) instead of up, like a roof by extrusion. This seems inconsistent to me and I think it whould grow upwards. What's your take?

[chodosh]

Jinkies! Good catch. I'm with you on this needing to be fixed and behave consistently one way or the other for roofs in general, but gravity usually wins, I'd like my structure to stay put and the assembly thickness to change as it would in the field more likely than not, beams and rafters below the roof, not within the assembly.

-LC

[dbaldacchino]

haha Luigi, that's when I find stuff out too, just when I'm trying to show something to someone and then look like a goober. This time I was working on modeling our house in my spare time (found some under the cushions on the couch) and was doing a round dormer with roof by extrusion and was expecting it to grow out and then figured I'll just offset the sketch. I kinda remembered that this is how it acts but at work, we seldom use the roof tool and we mainly default to the floor tool. Sometimes inconsistencies just jump out at ya

[sbrown]

The reason it grows down is because you are drawing the top edge of your roof, you can't draw the bottom because then how would you change the roof end conditions. And typically with roof by extrusion you are drawing in elevations so you would be sketching the ridge to align with another ridge or something like that.

[dbaldacchino]

Well true, but as long as you know the roof thickness, you can always offset the sketched line. I guess this is a topic that can be argued both ways. In my case, I knew what the inside dimension is (measured the dormer on the interior) so I wanted the roof to behave like the roof by footprint and grow up. It just seems inconsistent to me although I understand your argument.

[sfaust]

I don't see how drawing the top or bottom has an effect on the end conditions...

[patricks]

I rarely use roof by extrusion, but sure enough, EVERY time I have used it, I ALWAYS end up sketching the bottom surface (because I know where I want that to be), and then I have to offset by the roof thickness. It always happens for barrel roofs, as I know what the bottom of the roof is sitting on and its radius. Then I always have to offset upwards, and its annoying as heck if anything changes.

[sbrown]

Sounds like we would like the option to choose a location line for roofs, just like we'd like a location line for ceilings and floors. ie core boundary that doesn't move when we swap types.

[dbaldacchino]

I concur, that would be nice. Basically anything built with layers could benefit from this. In the case of a roof or a ceiling, having flip arrows or something similar would just change the offset rather than mirror the object.