overlapping faces in DWG from AutoCAD - how to fix?

[Rich O]

Importing a DWG a client created in Autocad, the walls (and only the walls) have overlapping faces evident when rendering (or in the viewport when converted to editable poly, a lot of 'z fighting' flickering). How would I go about fixing this? It's not the first time I've encountered it on a model from this particular client.

 

Here is a link to a small scene demonstrating the problem if anyone wants to have a look https://www.sendspace.com/file/oh202n

[notamondayfan]

Re-model it in Max properly. I never trust an AutoCAD model, and I almost never use one in a visualisation.

[Morne Erasmus]

Importing a DWG a client created in Autocad, the walls (and only the walls) have overlapping faces evident when rendering (or in the viewport when converted to editable poly, a lot of 'z fighting' flickering). How would I go about fixing this? It's not the first time I've encountered it on a model from this particular client.

 

Here is a link to a small scene demonstrating the problem if anyone wants to have a look https://www.sendspace.com/file/oh202n

 

I've looked and I doubt that was originally modelled in AutoCAD. You may have received a dwg, but I see what you mean. I usually get geometry like that from skp files.

 

Anyways, depending on how much time and effort you want to put into it:

As Dean suggested, just remodel it. It's such a small file and only a couple of walls.

 

OR

 

If you're tight on time, this will take you 5 seconds:

Remove the "Normal" modifier

Go into Element Subobject mode in any of the walls and attach all the other walls to it

Go to poly subobject mode and press ctrl+A to select all polys

Clear all smoothing groups

Done on the geometry side.

Now for rendering:

Since it's all walls and the double faces will get the same material anyways, and since you're using VRay, go to your global switches and increase your Secondary rays bias slightly. Default is 0.0. Maybe try 0.001 or 0.01 in extreme cases.

 

Enjoy!

Edited April 1, 2015 by Morne

[elipan]

I never trust anything other then AutoCAD models. Like Morne said, it was probably exported to DWG from other software.

[Rich O]

He definitely modelled in AutoCAD, it's all he uses. Specifically the offending faces are all one 'element' associated with the window sills.

 

I've fixed it by manually deleting them and then bridging the gaps but on a larger building this would become an issue. So your method sounds very useful, Morne!

Cheers

[Morne Erasmus]

That mode is not ideal. Check if your guy is modelling using solids or faces. Solids would be much better.

You can also try importing the file differently