[Wish] Globally disable Perspective projection


It would be handy to have the ability to globally disable the perspective projection and force Rhino to only work in parallel projection.
Perspective projection is a nightmare for technical stuff and navigation in big models. When zooming in a lot, the camera gets always stuck at some point.

if your zoom gets stuck, simply select what you want to zoom to then use -zoom _selected this will reset the camera focus and allow you to zoom in “closer”

Hi @theoutside ,

Thanks for your support, but I’m already using ‘Zoom Selected’ a lot (assigned to my mouse mid button).
In my opinion, this is just a workaround to make the navigation in perspective projection a bit less painful… When you’re navigating in the model, you shouldn’t be forced to select an object (which also can be locked and therefore not selectable) and type some command just to be able continue to zoom in/out.

This is obviously not ergonomic at all, as you’ve to perform three extra actions (1. choose an object - 2. select it - 3. execute the command) that have absolutely nothing to do with the original intent of navigating the model. Although I got used to it over the years, it still feels unnatural and cumbersome.
Not to mention the non-linear zooming increments in perspective mode, which sometimes makes you overshoot the geometry you’re interested in…

The parallel view fixes all these issues, and also become my favorite projection mode. Unfortunately, I never found a way to switching between 2d/3d without landing on perspective mode at some point. I also defined an alias to quickly switch between perspective/parallel as follow:

!-_ViewportProperties _Projection _Toggle _Enter _Enter

But again, this implies an extra action, that occurs maybe hundreds of times each day.

It definitely should be possible to decide between Perspective and Parallel, and stick with it while switching between 3d and 2d.

If you are zooming using the scrollwheel, try holding ALT - this way you would not get stuck.
Just scrollwheel moves camera closer to target vs. ALT version moves them both, therefore you never end up too close and stuck.


Holding down Alt key does not influence zooming with the mouse wheel.
You can use TwoPointPerspective command and Perspective command to change the perspective projection.

It does. You’re mistaken

Try this:
While the Perspective view is active, run the Camera command and Show it.
You’ll see the parallel view frustum in the other viewports.
Zoom back in the Top viewport so you can see the pyramid.
Now in the Perspective view scroll the wheel back and forth.
The pointy end of the pyramid (camera point) will move the the rectangular base (target) will not.

Now hold Alt and wheel Zoom again.
You’ll see the camera and target locations both move together just like wheel zooming does in parallel projection viewports.

Holding ALT will never get you stuck since the camera and target move together, but you can get “past” the object you may be interested in, so it is best to be aware of the difference and use both, as needed.

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Zoom Target is also very useful in some cases.

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I was wrong on Friday the 13th after sleepless night. :sleeping:

Are we not missing the point of his request wish? I think he wants a global setting to set views to parallel so that when he opens new files he doesn’t have to constantly use his macro. He might be opening many files a day and then he will constantly have to use his macro thus his wish for a global setting. Imagine he first has to seek out the views that are perspective then run his macro and do this for every file he opens. I can see that his request would be a time and frustration saver for him

That could be done just with a template with parallel views only to use for any new file. I though the OP did not know the not easily discoverable methods of avoiding getting stuck. I work in Perspective mode only 99% of the time with no view navigation issues.