Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Tom on 2023-04-09, 08:35:06

Title: Issue with UV tiling scanned material
Post by: Tom on 2023-04-09, 08:35:06

Hi,

I applied a Corona scanned material to a car paint, then I hit the "Adjust UV tiling to an object", selected the car body and then I receive the following message: "uv and v directions are not orthogonal (the measured angle is 82.3745193 degrees) so the scaling may not be precise. Would you like to continue?"

If I say Yes I can see Coordinates > Tiling values are now populated with non zero values, which seems good at first sight, but looking at the rendering I see the material is still wrong:  material flakes are huge and look unrealistic.
And then if I change U, V tiling values it doesn't change anything in the rendering. So I can't seem to find a way of having this scanned car paint material working fine.

Can you help ?

Thanks a lot guys,

Title: Re: Issue with UV tiling scanned material
Post by: Juraj on 2023-04-09, 13:30:14

The UV adjust tool is very finicky, I only use it on boxes which have similar UV mapping to my object. So if my object is 100x100cm sort of unwrap, I apply 100x100cm box mapping to box, and use the UV adjust on that.

With Car Paints, you can get away with Triplanar though. Depends on individual scans as some with strong anisotropy get completely broken with.

Also, I think I ran into issues where carpaint had internally wrong scale I believe, could also be the case. It just looked wrong, same as you mention, unrealistically big.
In the end, the Car Paint even caused artifacts unless I massively turbo-smoothed the geometry.

Car Paints are one of the less great ChaosScans.. The fabrics are much better.

Title: Re: Issue with UV tiling scanned material
Post by: Tom on 2023-04-09, 14:41:32

Thanks a lot Juraj.
At the moment I went for other scanned materials that do the trick for my cars.
In the future I will keep what you say in mind and have go.