Best way to push pull / extrude a non-coplanar surface? (e.g. hip roof)


#1

Please refer to the following screen shots in my question below:

Struggling to find the best way to give thickness to this flat surface hip roof - Figure A

So that it looks like Figure B (obviously I’ve achieved it in the end, but only by manually drawing every single edge with the line tool!)

The built in Push Pull tools works great, except it leaves these ridges - Figure C

Tried using the extension Joint Push Pull. This works well and gets rid of the ridge issues by extruding as a single surface. However, it is not extruded perpendicular to the exposed front edges, so I cannot extrude out to form the roof lip in the same plane as the roof (it sticks out a bit more horizontally as shown Figure D). The built-in Push Pull above didn’t have this issue.

Finally there is the gaps in the four corners of the roof after extracting the overhang (not too bothered about this, as fairly easy to heal manually).

Surely there must be simple way to extract a non-coplanar surface like this to give it thickness without having ridges to heal? Sorry if I’ve missed something, new to Sketchup and on a learning curve…


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#2

How about Vector Push/Pull in the Joint Push/Pull tool set?


#3

If I were trying to do that, I would draw half the roof in section (ie. in the vertical plane), then draw a suitable rectangle to create a path. Finally I would use Follow Me to get the section created to follow the rectangle edges.

If the rectangle is not part of the path itself, you might have to erase it afterwards.


#4

Many thanks. I had tried that, and got the same result in your animation. But the problem is that the resulting edges are not perpendicular to the roof plane - so then I cannot extrude them out.


#5

Thank you. I don’t quite understand that, would you mind elaborating? (not your fault, my lack of experience…)


#6

Like this:


#7

I thought you wanted the fascia to be vertical. Simon’s method would be the most expedient then.


#8

Thanks for your time, yes that certainly does it.


#9

@simoncbevans method is what I would do as a first choice. His VCB is cut off in the video, but when he’s making the roof angle, you can type in a slope like 6 in 12 (6:12) instead of some odd number of degrees, which is often how you want to think out a roof problem.


#10

Tig’s “ROOF” extension.


#11

There’s also the very basic, lift method.
RoofLift


#12

I think you’re missing the point. What the OP wanted was a more complex roof edge detail showing the tile overhang. I am not sure there is a quicker or better way than what I described, but I’d be glad to learn it if there is.


#13

Yes, I just used the 30 degree mark on the protractor as that is a common roof slope and suits most tiles but you can of course type in whatever angle you like.


#14

From the OP

And so I answered that question. And when done to the right size will form the overhang.


#15

OK, but are you sure you are not confusing eaves overhang with tile overhang? There are two. The eaves generally overhang the wall below and the tile edge overhangs the eaves fascia in order to drip into a gutter.


#16

The overhang was a secondary issue. How it is created could be a whole other thread. What about the rafters, the ceiling, the tile battons etc etc.
The main question was , how do I make a roof with thickness.


#17

Really? Figure A in the OP showed that @aquacruise already knew how to create an eaves overhang. Figure B and the shadowing suggests that what he/she meant by thickness was roof cladding thickness.

I agree that the model is “incomplete” without the various components that go to make up a roof but this might be a planning stage drawing. All you want is for it to look right in elevation or perspective. No need to spend time on minutiae.


#18

I repeat. and have nothing else to add.


#19

Well, if it’s a matter of modeling thickness to the roofing material itself, then the Joint Push Pull extension is just the tool with the expansion direction normal to the surface plane (not vertical). It adds the right amount of thickness, heals all the hips, valleys and ridges and makes the edge square to the roof plane, not plumb which is true to real world.


#20

I’d use Tig’s roof as a starting method for the basic roof, which auto draws soffit and facia thickness to spec. Then use Joint Push Pull in joint push pull mode and use “leave original face, reverse if necc” option. Also be sure to set the countours on in the extended options it offers. Many JPP users aren’t aware of these finishing options and they help get what you want. This thickens a surface perpendicular to planes of the hip, and you’d be doing so after you set the hip’s extents in Roof by TIG.

If you want a descending jetted soffit off a hip, such as craftsman style at times uses, select “sloping/sloping” under the facia/soffit settings in TIG’s Roof extension. It takes all the work out of it.

Now, in a case like fig D, to extrude out the roof tile or deck only, over a horizontal soffit and vertical facia, simply select ALL the perpendicular facia edges you generate with JPP and JPP them all together. Not one at a time. Doing them all simultaneously will cause the descending rafter tail effect you want. So take figure D, not one facia face at a time, but with all facia surfaces selected, then run JPP and voila, it’ll do just as you desire. For this one, be sure your finishing options don’t leave original face, but erase it out for you. Super easy, and I believe you’ll achieve your result. Run the order of operations as I described, and you have a cross sectionable roof with planes denoting rafter surface, deck surface etc, not an empty shell good for exterior views but not a detailed cross section.

These two extensions are invaluable for avoiding overmuch manual extrapolation of roof planes, but at times, the only method is a follow me profile method as others laid out. Multiple passes with multiple profiles can create the layers of roof for cross section, but honestly, it’s simpler just to draw one or two typical details in 2D and run with it rather than managing an overly complex model. Say it’s revisions time and you wish to lengthen a portion 2"? Now you have a plethora of things to mind, whereas a simple shell and detail approach makes revisions fly much faster, good for one’s sanity if you do this on a regular basis.

Happy sketching!