Why am I getting a negative measurement using push pull


#1

Why is it that when I pull out a surface with the push/pull that the measurements are negative?


#2

It depends upon which side you’re pushing or pulling on. Faces have fronts and backs so there’s positive and negative directions. It’s really not a big deal and it’s nothing to worry about.


#3

I am on the inside of a wall (actually I am following along with the sketch up video # 3) on that wall I pull out a block. I then double click the other block on the same wall and it goes backwards. It seems to do that every time on other areas.


#4

Are you referring to creating the built in cabinet boxes? Double clicking on the blocks is not shown in the video–at least least in the #3 video I just watched. It is shown on the window but no distance was typed in for the Push/Pull distance.


#5

When you pull a face drawn on the ground plane or off by itself in space, SU assumes you’re creating the exterior of a positive volume, and extrusion values are positive.

When you pull out a face inscribed on another face, SU assumes you are creating a negative internal volume–a cavity–and extrusion values are negative. It uses the same kind of logic to determine whether faces are front (white) or back (light blue).

Observe:

-Gully


#6

DaveR, I use the double click short cut after the first pull or push. I know that function is not shown.


#7

Gully, thanks, that explains how sketchup operates but it is still a mystery why sometimes the double click short cut sends the push in the opposite direction.


#8

Typically the dbl click action repeats the most recent mouse command. For instance when you Push-Pull a face up along the blue axis for a distance of say 10 feet. the very next subsequent P-P action on a different face should result in the face being raised an equal distance along the blue axis; however, SketchUp is sensitive to other influences that may accidentally affect subsequent actions. Things such as hitting a key or touchpad may alter the dimension SU acts on and some actions may impact the positive or negative direction of the next P-P action also. An inadvertent mouse click will also redirect the next P-P action.


#9

Sounds like face orientation, which is essentially what @DaveR said. If you Push/Pull a white face and then repeat it on a blue face, it will extrude in the opposite direction.

-Gully


#10

OK, things are starting to make sense now. I am not using a mouse, since I am working on a MacBook Pro, hence no mouse but using the track pad, that may be the cause of some of my problems.


#11

You should get a simple three button mouse. You’ll find it a whole lot easier to work in SketchUp with it as compared to the pad. I use the least expensive Logitech wireless mouse I could get. Plug and play and it works beautifully.


#12

That sound like a good plan, I’ll give it a shot.


#13

Hi im having trouble working out why push pull isnt working the way i thought it does as well.

Im creating a pvc window frame with mullions. The window was initially just a flat representation of a window as in the mullions were just lines drawn on the surface.

The plugin solid inspector doesnt like this, so im push pulling the mullions by mm and well its not creating a box form as i assumed it would.

I push the surface from the front 2mm back and i pull from the back to where i want it to end. But i find out orbiting to the front of the window that as i have pulled from the back this has reflected in the front moving all the way back. So in fact all im doing is pushing and pulling one flat surface. What am I doing wrong?


#14

I can’t quite follow what you wrote. Could you upload your model or a picture?


#15

I’d suggest at a guess that you just need to tap ctrl when you start the push/pull to create a new face.


#16

Thanks for the replies guys… i’ll try and grab a picture the next time i encounter the problem…

Basically if im pulling a surface from the front to create a box, and adjust the depth from behind the box/ inside or underneath the box i end up creating “shelves” on the other side which i have to manually erase…

Um thanks guys I think i might have solved a few of the problems that i wasnt recognising and yes hitting the Ctrl button I think solves the problem i was illustrating with the above image. I just didnt understand what the plus sign meant and that i needed to create an extra surface, when pulling and pushing from the same surface.

This has also helped me understand by accident what internal face edges are in my windows using the solid inspector. Its just really hard to see what solid inspector is highlighting, even in xray mode. I just need to hunt down the rest of the internal face edges that are not in my windows which might be another problem.

Is there a way of having the styles buttons or more specifically the xray buttons as seperate buttons along my side bar, which i can just click without me having to go into the drop down menu? Ive seen it in a few videos where its just a solitary group of buttons and ive noticed how my button layouts are different


#17

Enable the Styles Toolbar
Click … View > Toolbars > tic Styles


#18

Thanks for that, very much appreciated