Flex Duct Visibility

[mwaespy]

Hi All,

I'm still pretty new to Revit and am working on my demoltion plan. I drew in everything as existing and am now in the process of demolishing what's necessary. However, I've run into a graphics/visibility issue. When I set the portions of ductwork to demolition and they're disconnected from their trunk line, they no longer show up on plan. See the attached pictures (before and after) please. The pieces will still show up when I zoom in, but immediately disappear after the zoom in/out is completed. 

Object details:

 - Phase Created: Existing

 - Phase Demolished: Demolition 

View/Plan Details:

- Ceiling Plan (yes, the ductwork is above the ceiling)

- Phase Filter: Show Previous + Demo

- Phase: Demolition 

Thank you

[HVAC-Novice]

You can use phases any way you want.... But in most cases I create existing items in "Existing" and demo it in the "New Construction" phase (same phase as the new stuff gets build). 

So unless you have actual phasing in the project (i.e. you bid out one part today, and the other part next year), everything that "happens" happens in the same phase.

Envision what happens in the real world. A contractor shows up and demolishes and builds new stuff in the same "phase". Modeling in Revit attempts to emulate how a building actually gets build. 

[RobDraw]

What is the order of your phases?

Can you share a model that exhibits the behavior?

You are going to get people saying that you shouldn't create a demolition phase. This usually isn't necessary unless it doesn't work for you. Since you are new to Revit, it's probably best to follow established best practices and do your demolition in a new work phase.

[RobDraw]

Many large projects have a demolition phase, a new work phase, and even a temporary phase in between. The nature of the project should determine how phases are setup in the model.

[mwaespy]

Hi Rob,

The order of my phases is as follows:

1) Existing

2) Demolition

3) New Construction

4) Project Completion 

Unfortunately, I can't share my model and I don't have time to create one from scratch. I'm sorry.

I've been working in MEP for 6 months now (and by no means am I an expert at all) and every single architect I've worked with has separate plans for demolition and new construction, even when the project is done in Revit, so that's what I'm sticking with. I understand that they technically take place at the same time, but to have both demolition and new construction on the same plan would make it look like a mess. The phasing has been set up by the architect as well. I'm still failing to see why the phasing is an issue when the plan's phase + phase filter match what the objects' phase is. The ductwork still shows up on plan, just not permanently. 

[RobDraw]

Hopefully the discussion about how to do phasing ends here. You are doing it correctly and you're right. It might not have anything to do with your issue.

We need more information about what is going on in your model. There are a lot of variables that can affect visibility and it's a lot easier to narrow it down with an example. 

Let's start with your phase graphics override settings. Post a screen shot. 

[mwaespy]

Thanks Rob,

I hope this is what you're looking for.

- Mike

[RobDraw]

Sorry, I meant the filters.

[mwaespy]

Rob,

Here are my phase filters.

[RobDraw]

Okay.

View settings are next. Share them all but I'm interested in filters first.

Get ready to share the settings for your flex duct, too.

Are you sure you can't create an example in less time than answering all these questions?

[mwaespy]

Rob,

For view settings, I'm not too sure what you mean. In the visibility/graphic overrides settings, only mass and parts are turned off for model categories. No filters are applied in the filters tab of visibility/graphic overrides. 

Edit: If it helps, this problem is occurring elsewhere on plan too. For example, I have  VAV box that I just placed and connected to my ductwork. A single line on the VAV has decided to completely vanish and only show up when zooming in/on. 

[mwaespy]

It seems like Revit does an absolutely terrible job at displaying overlapping objects. Much easier to handle in AutoCAD...

[RobDraw · Accepted solution]

Actually, it's just the default settings. You can control how things display.. That sounds like you may have to adjust your hidden line gap settings.

[mwaespy]

I'll try, but it seems to be a problem on Revit's side. It thinks something is hidden when it's not. A duct 1 foot above the ceiling unobstructed by anything should not be hidden. 

[RobDraw]

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@mwaespy wrote:

I'll try, but it seems to be a problem on Revit's side.  

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Doubt it but, since I don't have the model, I can't say for sure. 

Wondering why you marked a solution if you think it's a Revit issue. As soon as you start thinking that, you've given up.

[mwaespy]

It turns out the problem is that reflected ceiling plans in REVIT look up so the software sees diffusers and grilles before ductwork. In AutoCAD the opposite is true. No one on my team has been able to successfully show the RCP and ductwork the way it should look (diffusers and grilles hidden below ductwork). 

It's pretty easy to give up when you're provided no training and on a deadline to finish a project. There's not a lot of time to go into deep dives on every facet of Revit's complex features and continuous errors. 

[RobDraw]

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@mwaespy wrote:

It turns out the problem is that reflected ceiling plans in REVIT look up so the software sees diffusers and grilles before ductwork.

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That is how RCPs work by definition, sort of. The viewpoint of an RCP is looking down at the floor and seeing a reflection, just like a mirror thus the reflected part. Revit has this right, no problem there.

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@mwaespy wrote:

No one on my team has been able to successfully show the RCP and ductwork the way it should look (diffusers and grilles hidden below ductwork). 

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Because that would be wrong in an RCP. You should be using floor plans.

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@mwaespy wrote:

It's pretty easy to give up when you're provided no training and on a deadline to finish a project. There's not a lot of time to go into deep dives on every facet of Revit's complex features and continuous errors. 

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[mwaespy]

> Because that would be wrong in an RCP. You should be using floor plans.

Really? Because every single plan that shows ductwork that I've ever worked with, whether it was made by the company I work for or received from many other companies is shown on a RCP. 

You're the one who brought "giving up" up. No need to get snarky with the memes.

[RobDraw]

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@mwaespy wrote:

> Because that would be wrong in an RCP. You should be using floor plans.

Really?

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That is how it's done in Revit. Why don't you try it? After that we can talk about getting the ceiling grid to show on your floor plans.

[iainsavage]

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@mwaespy wrote:

No one on my team has been able to successfully show the RCP and ductwork the way it should look (diffusers and grilles hidden below ductwork). 

---

You have to realise that Revit creates a 3D model, not drawings, and views are just slices of the 3D model, so elements closer to the viewer will hide elements behind them - like in the real world. In a RCP the grilles and diffusers will always hide the ducts behind them, except in wireframe.