Underlay behavior

[Anonymous]

Can you explain how underlays work?  We frequently find that if one is on level1 and underlays level 2, they actually see the level above.  

[Karambaki]

The behavior of Revit 2016 Underlay's tool is simply, mostly it looks from the bottom of the level whether up or down (As you specify in underlay orientation planview, or reflected ceiling plan)

Please note 2016 is not that clear of it's underlay behaviour as there's no way to specify the range of it.

When Am on level 1 , and my underlay is 2
Then i see 2 in gray scale

When am 5 and my underlay is 1
I see 1 in gray scale while the main one is 5

I believe that the Revit team is considering improvements to underlay behavior for release in a future version.

Edited by
Discussion_Admin

[Kimtaurus]

I'm having similar issues with the underlay function.

I'm on level 0, I've hidden the wall and winodw categories, so I can only see the walls. Problem here is I don't see the overhead lines.

So I figured I turn on the underlay and set it to level 0, orientation "look up".

Unfortunatly the top parts of the wall still don't show up. I should be seeing the edge of the openings.

I've attached 3 screenshots.

1: general plan; 2: plan without doors-windows, underlay selected; 3: underlay settings

The fact we can't change the Top Level of the underlay is definetly a limitation. Thinking about submitting this as a Wishlist item (in about 10 years Autodesk might add it )

[chrisplyler]

"I'm on level 0, I've hidden the wall and winodw categories, so I can only see the walls."

That doesn't make any sense. You've hidden the wall category so you can see the walls? No sense at all.

Anyway...perhaps you can make a new Level and Floor Plan view specifically just to show what you want and use it as an underlay. Raise this new Level up until your underlay captures what you want it to capture. Then go and hide it in all of your elevation views since you don't really need it to show up in your drawings.

[chrisplyler]

"When Am on level 1 , and my underlay is 2
Then i see 2 in gray scale

When am 5 and my underlay is 1
I see 1 in gray scale while the main one is 5"

Yes. The level you choose to underlay is the one that shows in grayscale. Are you expecting something else?

[Kimtaurus]

@chrisplyler I meant door and window categories.

[chrisplyler]

Okay. Forget my suggestion anyway. I tried it and cannot make the underlay show the dashed lines (or any lines) typically used to represent portions of walls above openings.

[Kimtaurus]

I've found an explanation on how underlay view depths work.

It's written for Revit 2012, but I've tried it in R2016, and I get similar results.

https://rvit.wordpress.com/2011/02/02/underlay-action-slice-slice-baby/

"The slice of the model between that level and the next level up, with an associated plan view, displays."

Also, you can only select levels as an underlay, if they have a floor plan associated to them.