Reflections not showing up from Background Image - modoplug Tweet

[teknofreek]

Hi thought I'd post as a new topic, but in some ways it's linked to my wanting to use background hdri's to light the environment and as reflections.

I've setup a scene in modo where there is a "Stainless steel" construction that is catching reflections form the "background".
In Modo it's fine the reflection shows up..

(In the pic its really extreme, but I'm trying to see whats going on, normally it wouldn't be so sharp..)
As can be seen, the render using the plugin seems to have no reflection in the materials at all. Now it may be a fault of the materials, but why does it work in Modo?.

I exported the same scene via obj, into Octane standalone and afaik set it up as similar as can be. (I did use stock Octane mats for the metal and the mesh as I was getting a bit frazzled..)
So in the Octane Standalone, I have the scene with the texture map loaded as an environment (Sky Texture) and short of it being a fair bit blurry, it works.

At a bit of a loss as to whats happening.
Attached are two pics showing the renders when in modo with the plugin and in the octane standalone. They're not totally the same, I had to muck around with the imager and a few other settings, as I was using a kodachrome setup in the modo plugin and since the plugin follows modo's camera, tried to replicate that without too much mucking around in the SO..

EDIT- I should have said also, in the modo / plugin pic, I have removed the back board to see whats happening with the background hdri.

Cheers
Gary B.

[face_off]

Hi Gary

You can export the Modo scene to Octane Standalone with the "Save to OCS" button. Then will will see exactly what the Modo plugin is doing.

It looks like an issue with the material - so if you post a screenshot of the Modo Material in the Shader Tree for the Stainless Steel material, that would help a lot. You can also add an Octane Override to the Stainles Steel material and increase the reflections as required. Check any of the Stainless Steal LiveDb materials in Octane Standalone to get indicative values. From memory, it would be a glass material, with Specular near 1, roughness near 0 and index > 1.4.

If all else fails and you cannot work this out - pls send me the lxo Modo scene and I will take a closer look.

Paul

[teknofreek]

Thanks Paul, I'd forgotten regards the Ocs export.
I'll try that and see if there's something different.
Yeah, if I can't sort it, I'll post the shader tree of the SS mat and/or send the lxo.
I'll also try using an override..

Cheers!

[teknofreek]

Ok, I exported the scene to Octane SO.
Quite interesting as it showed up almost the same as the behaviour in the plugin viewport.
Looking at the imported materials.
Initially I couldn't see what was wrong/different, until I clicked on the material and the "ball" material preview render came up..
it looked quite matte.
So I think roughness, dialled the roughness back and voila! sure enough the material came up nice and "mirror like".
With this came the reflections.. doh!

It seems that Octane is very sensitive to how it sees roughness set in Modo. Now this may be correct behaviour, but based on how modo responded quite reflective with the initial material setup, it was not an obvious thing to check. (Plus there was a bit of noob-ish inexperience at play as well...)

Pretty happy with how it's coming out now!

ps... I'm still having an issue with the blending of the cat-dog image map to an underlying "SS material". In Modo I'm using multiply, but I'll check a few things here.. maybe use an alpha transparent image or whatever...
The idea is to replicate etching an image onto a stainless steel sheet...

[face_off]

It seems that Octane is very sensitive to how it sees roughness set in Modo. Now this may be correct behaviour, but based on how modo responded quite reflective with the initial material setup, it was not an obvious thing to check. (Plus there was a bit of noob-ish inexperience at play as well...)

The material conversion rules are at http://render.otoy.com/manuals/Modo/?page_id=35. Can you post a screenshot of the Modo Material properties pls?

ps... I'm still having an issue with the blending of the cat-dog image map to an underlying "SS material". In Modo I'm using multiply, but I'll check a few things here.. maybe use an alpha transparent image or whatever...
The idea is to replicate etching an image onto a stainless steel sheet...

You can do this with a Modo Layer Mask (see http://render.otoy.com/manuals/Modo/?page_id=1096). Internally, that uses an Alpha Image attached to a Mix. In the mix, put the SS material in texture1 and the cat-day material in texture2.

Paul

[face_off]

It seems that Octane is very sensitive to how it sees roughness set in Modo. Now this may be correct behaviour, but based on how modo responded quite reflective with the initial material setup, it was not an obvious thing to check. (Plus there was a bit of noob-ish inexperience at play as well...)

The material conversion rules are at http://render.otoy.com/manuals/Modo/?page_id=35. Can you post a screenshot of the Modo Material properties pls?

ps... I'm still having an issue with the blending of the cat-dog image map to an underlying "SS material". In Modo I'm using multiply, but I'll check a few things here.. maybe use an alpha transparent image or whatever...
The idea is to replicate etching an image onto a stainless steel sheet...

You can do this with a Modo Layer Mask (see http://render.otoy.com/manuals/Modo/?page_id=1096). Internally, that uses an Alpha Image attached to a Mix. In the mix, put the SS material in texture1 and the cat-day material in texture2. Only Diffuse Color is supported automatically at the moment - but if you add an Octane Override, you can tweak it from there.

Paul

[teknofreek]

Hey Paul, thanks for the replies..
I have had a closer look at this issue and perhaps the way Modo was showing the reflectivity related to roughness, at least in the preview renderer, it threw me a bit.
Looking at roughness in Octane it ranges from 1 to 0.000.. and what I needed to set was around 0.03. The initial modo 70% roughness equated to 0.420 or something around that. ie approximately halfway, so I was a bit confused.
When I think more about it if 1 was 100%, therefore 0.03 is 3%, this is close to what I actually set in Modo of 5% roughness.

Anyway I'll post the pics of the material setup anyway for completeness..

Hopefully you sorta can see that the render in modo does not follow visually the same as the Octane render and that ultimately was what threw me.

EDIT- ps I just had a thought.. often I see on the fourms re modo's decoupled this and that... I just started wondering if the rendering of the materials in the preview do not follow. That is specularity and reflectivity are not coupled...
Using match specular in the material properties produces a much better correlation between reflectivity in modo and octane.
Modo does seem to still modifiy the surface with roughness AND specularity/reflectivity. ie It appears to be a micro surface effect. So reflections go up with increasing spec (as it's increasing the reflection value, but it's certainly more "blurry")

Thanks for your help, certainly I have a better understanding of how things are going now.

[riggles]

Your MODO material doesn't have the "Blurry Reflections" checkbox enabled. That's why the Preview window shows a mirror-like reflection. Also, IIRC, Octane has a higher range of roughness than MODO does, so percentages you're used to using don't match up to decimal equivalents if used in Octane.