When I create a new file the horizon line is always coincident with the X axis when viewed from the front with Parallel Projection :
After some modeling the horizon appears above the X axis under the same viewing conditions:
This doesn’t happen for every model but it happens quite frequently.
I’ve messed with all the settings I could think of that might affect this but haven’t found a way to restore the coincidence. What am I missing?
It would help if you share the model file so we can see your exact setup. Looks to me as if maybe hitting Zoom Extents would sort of out. Create a scene for the desired view so you can return to it.
Best practice is to avoid modeling with the camera set to Parallel Projection. Doing so can result in the camera being set up and a huge distance from the model. Do your modeling with the camera set to Perspective and save Parallel Projection for scenes for different views in your model.
What version of SketchUp are you using? Please complete your forum profile.
Sure, here’s a current example.
Power Strip Sketch 3b - Schurter.skp (598.8 KB)
If I’m modeling objects for fun or for 3D printing (which is 99% of what I do) I almost always use PP. I only switch to Perspective when I want relax and admire the model as a whole. For the doodads I print I have little use for fixed views so I rarely use scenes. I also model in meters instead of millimeters (yes, 1000:1) because it lets me get tight radii without having to constantly resize geometry. Slicers always correctly translate to mm so there’s no friction on that end.
I filled out a little more in my profile.
SketchUp was designed for modeling in Perspective, though.
That’s good. I’ve taught that modeling method for 3D printing for years. Not germain to the issue though.
I’m nothing if not defiant.
If you turn off the sky the horizon will be irrelevant.
True. But are you not a little curious?
I’m curious.
I downloaded your file, which does show exactly what you described, but despite loading a dozen or so of my own models I’ve been unable to reproduce the effect.
Is this some kind of trick? 
Not even a jot.
Well, just a little bit. What you say doesn’t reflect what is logic.
Front view in ‘Parallel Projection’ means that the ground plane is just on the horizon.
With your (one’s) settings you can deceive that SketchUp isn’t doing its job right.
Here I used your file to show that I can easily reproduce what you see:
Sorry. I got dragged away from my computer for a while. @Wo3Dan clearly shows what happens and why.
Hmm. I can reproduce that, but you can see the green axis going to the vanishing point. The only way to hide the green axis (behind the blue one) is for the origin to be dead center of screen.
Sorry, Wo3Dan. I don’t understand what you’re getting at.
My screenshot clearly shows the camera set to Parallel Projection. Your screenshot clearly shows the camera set to Perspective with an FOV of 1. These are completely different viewing conditions.
Are you saying that my model—when viewed on your computer—shows the X-axis coincident with the horizon line? In Parallel Projection?
I’m not sure what’s happened in your model. When I make a standard front elevation with Parallel Projection in one of my models it works.
I suspect this is because your model is huge.
When I scale the model down to 1.1m it seems to work fine.
It also may have something to do with the transition from sky to ground transition, and at the original scale it is showing you a clear dividing line instead of the faded dividing line seen in the smaller scale model:
But!
When I copy your giant ass plug thing into a new template it works fine… so… maybe just do that and see if it works?
And for a few dollars more we’ll include:
When I change to different styles it seems to work as well:
That’s interesting. My steam engine model is huge.
Stay out of the air in Austria, Mike. Sounds kind of dangerous.
ok, I didn’t read this the “right” way at first, I’m still giggling 
I have seen the video, lucky, all around.
I have had a Swiss military helicopter fly under me, and moments later the Swiss acrobatic team flew past. Last fall I landed, heard the sound of jets, and not far from where I was 5 minutes prior 2 Swiss F18s went ripping up the valley.
What happens if you copy / paste your model into OPs model?
Intentional? Or not? The world may never know.
