Maya/Octane scene scale question Tweet

[itsallgoode9]

This is kind of a dumb question, considering how long I've been working in Octane, but what is the correct way to set units/scale in maya when rendering with octane.

Do I leave maya in CM then change Octane scale to .01?
Do I leave octane Scale to 1 but then change Maya units to M, as the maya dialog recommends, if octane scale is adjusted.

If I change Maya units to M, but I originally created my scene in CM, does octane then see my object as 10m large instead of 10cm?

Are there definitive settings you can provide so I make sure I have my scale settings right?

[fantome]

I would have the exact same question.

i don' t get how scale work between Maya and Standalone.
- when i create an object of 10cm in Maya
- i export it as .abc
- i load it in standalone with the .abc scene loader that i set to .cm
- the scale looks to be correct in standalone
- BUT when i save the standalone scene as orbx
- and then load it in Maya with an OrbxProxy, the scale is wrong
- i have to scale it by 100 to get back on my feet to match the scale of my intial 10cm object

so what is the proper workflow to be sure that my obj is :
- 10cm in maya
- 10cm in octane standalone
- 10cm when imported as orbx proxy inside maya

Also if you know where i can find a reference object provided by otoy that i could use as reference in standalone as measure reference that would help ?
I have to be sure that my metrics are good.

Thanks for your lights !
Cheers
E

EDIT :
viewtopic.php?f=28&t=53897

some interesting stuff here

[fantome]

https://docs.otoy.com/StandaloneH_STA/S ... trange.htm

OctaneRender® expects one unit in the scene to equal one meter. Adjust export settings in the modeling application, or adjust the import settings in OctaneRender®.

[itsallgoode9]

Unfortunately that doesn't help much with rendering within maya, as there are two different ways to change the scene scale:

Scale method 1--Changing maya units to M, while leaving the Octane Scene Scale setting to 1
Scale method 2--Keep Maya units in the default CM, while changing the Octane Scene Scale to 0.01 ((1m (octane's scale) = 100cm x .01 = 1 cm (maya's native scale))

mathematically, both methods should do the same thing (?) but in reality the affect the scene very differently, which is where my recent confusion has stemmed from. Or it could be i'm just misunderstanding scale.

[fantome]

well from my current test.

the only way to get a proper reference if we trust the doc :
- in octane standalone 1 unit = 1 meter -> i have read this in many different place in the doc
- so i have created a cube primitive geometry of 1 unit = 1 metter as reference.
- when i set my scene to cm in maya settings and export a cube of 100 maya unit (cm) in octane standalone with maya .abc exporter ( not the otoy one ). i get a perfect match in scale with the 1m octane cube
- when i set my scene to m in maya settings and export a cube of 1 maya unit (m) in octane standalone with maya .abc exporter. i get a perfect match in scale with the 1m octane cube
BUT ...
- when i set my scene to cm in maya and import the orbx of the cube with 1 octane unit ( 1 meter) , as an orbxProxy, i have to scale it by 100 to match the 100cm Maya cube
- when i set my scene to m in maya and import the orbx of the cube with 1 octane unit ( 1 meter) , as an orbxProxy, i also have to scale it by 100 to match the 1m Maya cube

so the scale equivalence looks to work when exporting with Maya .abc exporter to octane standalome , ( i never use the otoy one because if have encounter many bug and weird unpredictable behavior )
but it looks that there is a wrong interpretation of the scale when using the orbxProxy so for the moment i put a placement node with 100 scale juste before the out geometry to counter balance that error.

[itsallgoode9]

sorry but that still doesn't answer my question. My question is about units and rendering WITHIN Maya ...

If I model in cm should I:

1. Switch scene units in Maya to meters before working on lighting/materials/rendering?
(which appears to cause no change whatsoever)

or

2. Should I keep my scene in CM and adjust the octane render scene scale parameter to 0.01 (which causes a huge
change)

or

3. Should I keep scene units at CM and Octane Render Scene Scale Parameter at 1.0

Which of those three methods is the correct way to handle Maya vs octane units WITHIN maya? Which is correct to make sure parameters likes Absorption, DOF, tiling and light intensities are correct when rendering WITHIN maya?

[fantome]

well from my additional test , i would say option 2.
keep scene in CM and set scene scale at 0.01. It's the only option that mimic octane standalone behavior with a cube of 1m with absorption.
but as i am no expert in octane, that would be nice if someone could confirm that.


EDIT :

After double testing, to get the exact equivalence between Octane for Maya and Octane Standalone you have to use this setup :

[Jolbertoquini]

Hi Guys,

Yes I understand is confusing, the correct way is keep my default centimetres because all other stuff and workflow in Maya are based on that and then on scene scale set "0.01" for correct size.

So Why the default is 1 unit = 1 meter, is just because the numbers on shaders and nodes and transforms is based in meters inside Octane.

Because maya units is has limitation you have to set the number divide by 0.01 to get accurate response of shaders and etc. But check the orbx export you will see there is just a placement node add on the end of the scene scaling everything down. is what that scene scale does basically.

Hope this help to understand a bit. I would work like that Maya default centimetre and Scene scale at "0.01" we are doing that for a while on production.

Best,
JO

[itsallgoode9]

gotcha, thanks for that! that's how i've been working lately, so that's good!

for clarity, does it affect anything beside slider scales? functionally, lighting, falloff etc works exactly the same, no matter how that octane scene scale is set and the octane scene scale slider doesn't affect that?--that octane scale setting is basically just a shortcut so you don't have to multiply slider units down? AKA, 1 absorption would work exactly the same as .01 absorption etc?