OTOY Forums

radiance wrote:Hi TIG,

can you test your smoothing with the default octane OBJ import settings ?

These are:

- import per material smooth value = ON
- use OBJ vertex normals if supplied = ON
- interpolate using smoothgroups = OFF

I think the issue is that if you enable the last parameter (interpolate using smoothgroups),
octane will simply recompute the vertex normals based on groups/edges and you don't end up using proper supplied vertex normals from sketchup.

As all users have these settings by default, it's important that the exporter writes out vertex normals properly so that it works like all the other exporters,
otherwise users will end up with several problems, for example you will lose control of normal direction which can cause artifacts in renders with transmissive materials like glass...

Radiance

TIG wrote: I have done further testing as you suggested and I concede that the newer version of the exporter does indeed mess with smooth normals, unlike the earlier version - my ticking of the 'smoothgroups' option was confusing the issue...
I will recast the coding changes made in the newer version of the exporter to keep the efficacy of the previous one.
I had made some slight changes to address a very rare flipped faces issue - better to keep the smoothing right and look for another solution to that one - watch out for a up date soon...

abstrax wrote:

TIG wrote: I have done further testing as you suggested and I concede that the newer version of the exporter does indeed mess with smooth normals, unlike the earlier version - my ticking of the 'smoothgroups' option was confusing the issue...
I will recast the coding changes made in the newer version of the exporter to keep the efficacy of the previous one.
I had made some slight changes to address a very rare flipped faces issue - better to keep the smoothing right and look for another solution to that one - watch out for a up date soon...

Sounds good. Thanks for your efforts

Cheers,
Marcus