Parts of wall disappear in 3D when shadows added

[stephen.melhuish]

I have a Revit model that has a thin cement wall added over the top of an existing brick wall. The existing brick wall is in the Existing Phase and the Render is in the New Construction Phase.

When i view the model in Perspective it is ok UNTIL I turn on the Sun (Graphic Display Options: Lighting), when the new Construction Phase cement layer partially disappears. Any thoughts ?

[barthbradley]

What's the View Phase Filter set to? 

Is the issue replicable? Create another like View and see.  

[stephen.melhuish]

Strange, I take a different 3D view, this time of the rear and get a different result for 2 different locations of the same elevation (see attached)

[barthbradley]

Shadows Produce Artifacts | Revit 2021 | Autodesk Knowledge Network

[barthbradley]

Are you using sketchy lines?  

Try disabling Hardware Acceleration.  

Help: Hardware Acceleration (autodesk.com)

[stephen.melhuish]

Unfortunately still no luck I'm afraid. I disabled hardware acceleration and re-started revit but still got the same problem. I'll re-do the perspective views and see if that will resolve matters

[ToanDN]

How thin is the plaster wall?

[stephen.melhuish]

The cement render is just 20mm thick. However, the same is also occuring with timber cladding which is 20mm thick with 25mm air behind

[BIM-CONG]

It seems like that the two "walls" including brick and cement ara overlapped.

[stephen.melhuish]

They don't overlap but I have found that if I move the New Construction wall I placed over the Existing wall away from the Existing wall then it seems to work.

[syman2000]

Do you have any CAD link or heavy 3d family inside the project?

[BIM-CONG]

Emmm it's a little strange, can you post a partial model with this issue?