Announcements
Welcome to the Revit Ideas Board! Before posting, please read the helpful tips here. Thank you for your Ideas!
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Two-Point Perspective Correction for 3D Views

Two-Point Perspective Correction for 3D Views

In 3D views, if you look up then you get parallax (walls are no longer straight up and down). But sometimes it is necessary to look up to communicate whats going on. It would be very helpful if 3D views could have an option to correct all walls to be straight up and down. Enscape has this feature built in, really nice.

9 Comments
gsucci
Collaborator

This is already possible to achieve out-of-the-box, since version... 1?

 

Just setup your perspective, then look at the property of your camera, and make the eye point Z the same as your target point Z.

 

Then you play with the bounding box of your view to enclose your building.

 

As long as the eye and target point have the same Z value, it will be a 2 point perspective.

_andyman
Contributor

Yeah i know that. Like i said in my post @gsucci  "sometimes it is necessary to look up to communicate what's going on"........... and by sometimes i mean a lot of times. In this scenario, the target Z value would be higher than the eye Z value and the entire view is warped and riddled with parallax. The feature idea i am describing would maintain the straightness of vertical lines even when you want to look up.

gsucci
Collaborator

Andy,

we are not being clear here.

 

I think you are talking about correcting perspectives so that the vertical lines are always parallel to each other and vertical.

 

This is called Shift-Tilt photography, and it ha been done for long time, first optically, then digitally.

 

You say that you want a feature that correct the vertical lines "when you look up".

 

This does not exist.

 

You cannot "look up" and correct the vertical lines at the same time.  Photoshop perspective stretch is a fake, it is not Shift-Tilt photography.

 

The way you correct the vertical lines is by using the Tilt-Shift photography technique, in this case, the Tilt part of it.

 

Please do an internet search of "Tilt-Shift Photography" and study it.

 

Then you can go back to Revit and apply the technique to your 3D view perspective, as per my original post.

 

Namely: keep your eye and target elevation EQUAL, and stretch your 3D view boundary up to show more of the building (this is the part that you erroneously call "looking up").

 

You can also rise or lower BOTH POINTS of your camera, effectively moving the camera up and down parallel to the ground, in order to tweak the composition of your perspective the way you like.

 

Let us know if this is any more clear.

 

regards

 

gio

_andyman
Contributor

I'm not suggesting any tilt-shift photography, just a two point perspective rather than 1 point perspective. Nobody should have to post production fix a one point perspective and learn about tilt-shift photography, just because they wanted to look up.

 

See this youtube (link below) for an enscape tutorial showing that this is possible. Start watching at 2:45.

 

https://youtu.be/xA6QRP6Ch6Q?t=165

 

 

gsucci
Collaborator

Yes, you ARE suggesting shift-photography: please educate yourself.

 

Enscape simply shifts the picture plane up and down to avoid having the vertical lines converge to a vanishing point.

 

It does NOT "look up" or down when the correction is activated, the eye and target elevations are simply kept equal, lock, if you wish, as I am repeating to you all along in this thread.

 

Again, you need to research this things so that you can understand how to do it, since obviously you still think that you cannot shift-correct your perspectives in Revit.

 

No developer will waste time on something that is already possible do achieve.

 

regards

 

gio

 

PS: your confusion about this subject matter is also obvious when you wrote: "just a two point perspective rather than 1 point perspective".  How does that apply to what you are asking?  Please research "2 points perspectives" and "1 point perspectives" and see what they are.  What you are talking about is correcting a 3 points perspective into a 2 point perspective (the third vanishing point, on the Z, becomes the vertical direction in the view, and no longer a precise point).

 

The branch of Geometry that studies this topics is called "Descriptive Geometry" and, believe me, is fascinating.


_andyman
Contributor

What I AM suggesting is adding/developing the feature from enscape (that they call) "Two Point" - previously referred to in older enscape versions as "Architectural Two Point Perspective".

 

Obviously some developers will spend time developing this feature given that they already did! and it works great! So great, that I came up with this idea where Revit could provide the same feature for their 3D views. 

 

FYI if you google "tilt shift photography in revit 3d view" the first thing that popped up for me was this: http://revitrandoms.blogspot.com/2011/08/aligning-verticals.html and the solution is exactly what you are describing "simply, don't look up".

 

Just to be clear i have provided enscape examples, in the pictures attached, where i am positioned low, and looking UP. If you still can't see the value in this feature after these photos then you obviously spend too much time thinking about how to respond to users on a forum rather than listening from a reflective point of view (pun intended).

 

PS: your lack of experience in producing renderings in an architectural work environment is obvious by the fact that you think that anyone would want to produce such works exclusively with level eyes and targets. Furthermore, what's really fascinating is that the developers over at enscape already made this happen and didn't title it "descriptive geometry", just "Two-Point". Probably because Two-Point perspective is a type of descriptive geometry.

 

Thanks.

 

 

 

1 point.png2 point.png

gsucci
Collaborator

Anyone else care to help andyman understand?

 

I am kind waste enough time here....

 

thanks

 

regards

 

gio

 

PS: have you look at this? : https://forums.autodesk.com/t5/revit-architecture-forum/how-to-make-2-point-perspective-view-in-revi...

_andyman
Contributor

That solution is by you and you say the exact same thing you keep saying over and over: To maintain the tilt correction you need to keep both eye and target elevations the same.

 

The whole feature i am proposing is where you could have, i.e., a eye elevation of 5'-6" and a target elevation of 25'-0" AND all walls remain straight up and down as though both eye and targets were the same.

 

Thanks.

Anonymous
Not applicable

Hi,

 

I think @gsucci is right. I believe that what you are asking is how to create what in photography is called an architectural perspective or a shifted shot; which in SketchUp and Enscape is called "2-point perspective", in 3Ds Max "vertical shift" and so on. With a real camera, you would need a shift (tilt-shift in most cases) lens and point the camera at the same height as your viewing (camera) height, and then use the shift feature of the lense to "shift" the framing vertically.

 

It is literally the same process in Revit: create the camera and make sure both Eye and Target Elevations have the same value, and then simply "Shift" or stretch the cropping frame upwards or downwards. I don't think Revit has the feature to correct the vertical distortion within the Camera parameters when the Eye and the Target Elevations have different values.

 

Hope this helps...

Can't find what you're looking for? Ask the community or share your knowledge.

Submit Idea  

Autodesk Customer Advisory Groups


Autodesk Design & Make Report