topic Re: Orthographicdisplay looks like a reverse perspective! in Inventor Forum

Orthographicdisplay looks like a reverse perspective!

m_m_heravi — Mon, 03 Apr 2023 00:19:25 GMT

This is driving me mad. Orthographic view looks like a perspective view, but in reverse. The edges in front of a cube looks smaller than the ones in the rear!

It has been there since V 2020. I am using V 2022 now. Some unknown setting has been very persistant in the past couple of upgrades.

The screen shot is taken in normal part editing environment. Even the ground is clearly showing reverse perspective.

Any ideas? Thanks.

Re: Orthographicdisplay looks like a reverse perspective!

Gabriel_Watson — Mon, 03 Apr 2023 04:29:27 GMT

Could be just an optical illusion to your eyes. Grab a ruler and measure on your display and you will see the distances seem ok and not smaller in front than the back.

Re: Orthographicdisplay looks like a reverse perspective!

pcrawley — Mon, 03 Apr 2023 04:34:11 GMT

Your screenshot looks Orthographic to me.

I copied your screenshot - painted a vector line over the rear upright edge, then moved the line around to measure the other two visible uprights. They are all identical. I repeated the process with the 'horizontal' edges and got the same result.

I then copy/pasted the line - moved each copy into place - then moved them together, and they are about as parallel as the calibrated eyeball can manage.

I recreated a 100x100x100 cube - but changed the visual style to show hidden lines so I could easily identify the back-left-bottom corner - and it still looks orthographic to me:

Re: Orthographicdisplay looks like a reverse perspective!

m_m_heravi — Mon, 03 Apr 2023 06:06:47 GMT

I really appreciate the time you spent on this, very grateful. After receiving your note, I measured the lines and they seem fine. But still the shape did look skewed, so I connected to my son's monitor and everything looks fine there! Can't imagine how a monitor can play tricks on your eyes, but it did!

Cheers buddy.

Re: Orthographicdisplay looks like a reverse perspective!

m_m_heravi — Mon, 03 Apr 2023 06:10:39 GMT

Thanks for the swift reply. I did check it (see my reply to @Anonymous ). Looks fine on another monitor, need to tweak around with my work monitor and see what causes this. Aspect ratio, color, ...?

Cheers.

Re: Orthographicdisplay looks like a reverse perspective!

EdvinTailwind — Mon, 03 Apr 2023 06:16:24 GMT

Make sure you're using the recommended resolution for the monitor you're using. If not, the width/height ratio might be incorrect and equally long objects may appear different.

https://support.microsoft.com/en-us/windows/view-display-settings-in-windows-37f0e05e-98a9-474c-317a-e85422daa8bb#WindowsVersion=Windows_10

Re: Orthographicdisplay looks like a reverse perspective!

m_m_heravi — Mon, 03 Apr 2023 07:37:05 GMT

I have been trying different settings. With a more square setting (like 4:3 or 5:4) it look better, but obviously I lose a lot of space here. Anyhow, I guess this is now a hardware problem and I would take it to the proper forum from this point forward. Thanks again for your and everyone's comments.

Re: Orthographicdisplay looks like a reverse perspective!

Gabriel_Watson — Mon, 03 Apr 2023 13:11:40 GMT

It's just the way the lighting hits the object, causing the left face to be darker, which adds a perceived sense of depth. No way to fix that with monitor settings.

I love watching optical illusion GIFs, so I am more aware of how lighting and color can cause perception of movement and/or stretch. We are also very used to Isometric views and Ortho takes a few days or weeks to fully adapt to.

At the end of the day, you gotta ask yourself why are you using Orthographic in 3D modelling. I would only use it for certain drawing views where someone needs to take a direct measurement on them. While modelling for yourself Ortho will just make your life harder.