Downloaded Models Render Too Dark Despite Same Material

[Oriana_Stuecker]

Hi everyone,

I’m working on a rendering of an urban site model. Most of the 3D models were downloaded from the internet, except for three that I modeled myself. All of them have the exact same material applied, but the downloaded models appear much darker in the final rendering - especially on their top surfaces, which look almost black. In contrast, the three models I created are rendered much brighter, as expected.

Interestingly, everything looks fine in the viewport - it’s only the rendered output where the issue occurs.

I’ve already tried converting the downloaded meshes to NURBS and rendering them again, but the result didn’t change - they’re still too dark.

I’ve attached some images showing both the rendering and my settings.

Thank you in advance for any help or suggestions!

[CADARTZ]

Check direction arrows have to face out

[CADARTZ]

Dir | Rhino 3-D modeling

[Oriana_Stuecker]

I already tried that too and flipped them all but it didn’t work.

They’re all facing out.

[CADARTZ]

Have you tried turning off “transparent background” option? Also See if Transparency does something to its set on 32 set it to 0

Dont have other ideas maybe the format of the image i know png can produce something similar

[CADARTZ]

this is what i see when i click the first image it is saved in png

i got similar results when i accidentally saved my render in png a while back

[nathanletwory (Nathan 'jesterKing' Letwory)]

Can you export the objects encircled here to a new 3dm file, then share that file here?

[Oriana_Stuecker]

Here.
By making this file, I realized that they are open on the underside. But I can’t cap them. Could that be the problem?

Thank you very much for your help.

Selected Houses.3dm (4.1 MB)

[nathanletwory (Nathan 'jesterKing' Letwory)]

The problem is that there are coincident faces

I isolated this building box

Run _What, which tells that there are 10 surfaces in the polysurface, even though only 5 is expected.

Then exploded it, deleted all double faces, rejoined. Now I can render it correctly (Raytraced uses the same engine as Rhino Render)

Here compared with the other houses that I did not give that same treatment:

To do all these in one go do the following:

1. select all your houses
2. _Explode
3. _SelNone
4. _SelDup
5. delete selection
6. _SelAll
7. _Join

This should give you cleaned up houses that render correctly.

I’d keep everything still selected and at the end run _MergeAllCoplanarFaces, that will clean up your house models even more.

From

To

Final

[Oriana_Stuecker]

Wow impressive! Thank you a lot!

[CADARTZ]

The many joys of mystery models