Sectional Perspective - controlled

[boyd.112779]

I have read most of the post in the forum on sectional perspectives using a camera, dynamic view, "orient to"...etc. I have not been able to find what I am REALLY looking for.

Here is what I'm after, appreciate any help.

A sectional perspective:

In a camera/perspective view I use the sectional box...what I would like to be able to do is have the sectional cut run parallel to my screen - the sectional box (by default) is oriented N,S,E and W. You can rotate the sectional box - but from what I can tell...without any precision. Ideally, if I could click on the section box and if I could orient IT to a specific view (better yet, a specific angle). All I can see that is available is orienting your VIEW.

I know I can create any type of section in plan (with precision) and then orient my view to that specific section, but I can't see how to get that section turned into a true perspective - going away from the section.
i.e. the section is to scale but the rest of the drawing present a realistic perspective image vanishing away from the section.

Please remember I am looking for a true perspective (vanishing points) AND to know that my section is cutting through my model at a controlled angle (not just by rotating the section box freely). If I rotate the section box "close" to the angle I want BUT if it does not cut through the wall perpendicular to the face...it is really not a useful section.

Thanks in advance...appreciate any help anyone can give.

PS
I have also tried to accomplish this in CAD - seems to be a lot more complicated...maybe I'm just stuck in how Revit works.

Boydj.

[Adam Mac]

Hi Boyd -

i've had a quick look at how to achieve this but can't help you mate!
There doesn't seem to be an accurate way to rotate the camera placement?

I'd be interested to know the answer myself!

Adam

[boyd.112779]

Adam,
Thanks for the response. If anything it was nice to know that someone else could not make this happen. I am thinking it just can't be done in Revit. You can come close, but not as precise as I really need it to be.

What I ended up doing was importing the model as a dwg into Sketchup Pro. Sketchup's section tool can be controlled similar to the section box in revit but with a lot more control and precision. I was able to rotate the section plane to the precise angle that I wanted and then turn on "perspective" and rotate the model to a view I want - while still having the section cut exactly how I wanted it. This only took about a minute - after I had spent about two hours trying to force Revit to the same thing.

If you have Sketchup - try it. If you don't, you may or may not know that you can download the free version compliments of Google. Although, I do not know all the limitations of the free version. You may not be able to import dwgs or even cut section.

I also think you might be able to do this in CAD but that seems a lot more complicated than I thought it should be.

good luck,
Boydj.

[Elmo]

Hi there, just wondering if this is anywhere near to what you are trying to achieve.

[dbaldacchino]

Well in plan, you're able to at least snap your section parallel or perpendicular to a line, wall etc., but we still cannot pick a point to start, so we still cannot place a section with precision, although MUCH better than pre 8.1.

I tried scope boxes, but once more you cannot align or snap the draggable sides. You can only approximate. Assuming you can approximate to an acceptable level, then you face the problem that you cannot take a 3d view, orient it to your section and turn it into a prespective, so I see your point. You then have to approximate once again the section box. If at least we could take that 3D axonometric view and turn it to a perspective view with the section box turned on, it would be much easier and quite acceptable for a 3D sectioned perspective.

[Steve_Stafford]

I must be missing something...

Create a section view, adjust the extents according to what you want to see.
Create a camera view
View > Orient > To Other View: choose your section view
Dynamically modify view to adjust the view so you can see what you want.

[Adam Mac]

Steve - i think this is the crux of the issue....


...AND to know that my section is cutting through my model at a controlled angle (not just by rotating the section box freely).

Boydj - thanks for the advice; yes, i already have SketchUp and am almost starting to think that maybe AutoDesk should think about aquiring that off
Google!!

Adam.

[dbaldacchino]

I tried what Steve suggested but I still cannot get that to work. Take a look at the attached. I have an axonometric sectional 3D view (that's easy...make a 3D view and orient to the section, then rotate around). But placing a camera in plan and trying to orient the view by Section 1 yields a wierd result. Something's not right.....when you select the crop region of the camera view, the camera icon in Level 1 stays set as where placed originally, and not to it's new location. Also, if you turn the section box on in this view, it won't be parallel to the section cut. Did I miss a step or did yours work because the section was not at an angle?

[Steve_Stafford]

It would help if the result achieved via sketchup were posted to see for comparison, otherwise we're just guessing back and forth.

[Tobie]

Steve, I think the problem is that the section box of the camera needs to be where the section line is for it to be a section perspective.
I would have to ask why you want a perspective section that is 100% correct to a section?

[Scott D Davis]

The problem arises because the section box always stays orthagonal to the plan view of the revit drawing window. So Steve's example works, because the walls are orthagonal to the drawing window. Imagine having a building that needed a section at a 45 degree angle. Drawing a section line at 45, and then using Orient to View to that section does not align the section box to the 45.

[boyd.112779]

You got it! I am trying to cut a section that is 45 degrees from the default orientation of the section box. If the section I needed to be cut was parallel to the the default orientation of the section box...there would be no problem.

You can rotate the section box to "approximately" 45 degrees, I could drag the box to where I wanted the section cut, I could then orient the camera to that plane (in a variety of ways) and I would be good.

PROBLEM:
The section box is not cutting through the wall at precisely 90 degrees (I would not know for sure). As you can imagine, it is nice to have the section cut to scale (to sketch out ideas by hand or for whatever reason) but then also get a realistic view of the rest of the space - this is something that has been done for years, by hand.

Without being able to control WITH PRECISION the rotation of the section box, I am unable to REALLY know that my section is to scale.
I don't think it can be done in Revit.

It works in Sketchup because you are able to specify any angle of rotation for the "section tool" - you can't do that with the section box in revit (unless I'm doing something wrong).

Thank you for all your suggestion. Has anyone done this in CAD?
Boyd j.

[captainbunsaver]

I'm still missing something here. I used a 3d perspective view (via the camera), then turned on the section box (which is very difficult to control when in a perspective!).
The vertical edges are skewed badly.

Elmo, how did you procude your image?

TC

[colin1182]

Sectional Perspectives:

1. Create a section through the building.
2. Go to View on the design bar and choose camera. Place a camera perpendicular to the section cut leaving plenty of space between the camera and the building. (This will be moved later so it isnt too important)
3. Go to "view > orient > to other view" and select your section from the list
4. At this point it should look like a regular 3D view. Now turn on a section box from your view properties.
5. You will not be able to see the drag handle behind you, so instead, click on the section box to highlight it and without clicking on anything else, double click on a floor plan from the project browser (any plan will work as long as it shows the information necessary for you to determine where the cut should be).
6. From this view, you will see the outline and extents of the section box in plan. Simply drag the edge of one side to where you want to cut the building(rotate the section box if necessary)
6. Without exiting the plan view, select the 3D view you created from the project browser, right click and select show camera. The camera will reveal itself on the screen.
7. You can grab the camera and drag it around to change its orientation to match whichever view you desire. (You may need to drag the camera focal point to control view range, just point it perpendicular to the section cut in plan)
8. Open back up the 3D view and you should have a 3D Sectional Perspective.
9. You may want to open up the View Properties (VP) and uncheck the box for crop region visible. Also, under the visibility/graphics settings (VG, VV) you can uncheck section box from the annotations tab.

[dbaldacchino]

Thanks Colin and welcome to the forums!

The method you described works well (although orienting to the section doesn't really do anything in most cases and is a step that can be skipped). For presentation reasons, the section box can be approximated to where you'd want to cut the section, although not with 100%precision (meaning, you cannot create a sectional perspective precisely where you've already placed a section, such as you can do with a non-perspective 3D view). But we can get pretty close. Now if only we could select a non-perspective 3D view and turn it into one :)