Softimage Scale Interchange with Maya

[RichardCulver]

I pretty much have the scale issue sorted with Maya. From my understanding based on a few threads, tutorials and my own tests to confirm, the Maya default scale internally is 1 unit = Centimeters. What this means to the XSI: "A unit can be whatever you want dude..."

http://download.autodesk.com/global/doc ... d30e245868

...is that size does matter when doing effects which is what I am thinking of doing with SI now as an external app to Maya and MotionBuilder/Mudbox as my central animation texturing and rendering solution.

I think when considering the pipeline above, it is best to keep everything in Maya units and model to scale based on Centimeters. This is in effect what MotionBuilder seems to be scaled to by default. And Maya is internally tuned to this scale so modeling to scale makes sense and then Nucleus (which operates in 1 Meter) can be scaled back to fit using the Space Scale parameter.

However from working in Softimage, I have adopted this scale:

Both the PhysX and ODE dynamics engines have been tuned so that 1 Softimage unit is equal to 10 cm.

This is consistent with he scale of the supplied rigs, meshes and default Biped Guide. And so all of my sets and characters have been modeled to this scale.

So now I am looking to go 10X from that in order to do some particles in XSI and port them to the new scale I am considering to adopt for Maya.

The question is... finally....

For anyone who has done this, are there any issues, showstoppers etc. in using a 10x scale with ICE? I mean as long as I keep the scale in mind with parameters will I be OK internally or will I wind up with any major issues down the road? Such as simulations wigging out or taking forever long with too many substeps etc.

I am looking mostly for warning signs. I'll be doing my own testing later, but for now I kind of want to settle on my scale for the project. So any advice on the ICE factor would be appreciated.

Thanks.

[Rork]

You would have to quickly test this, but upping the scale 10x to a meter might get you into trouble with simulations.
afaik it's tuned to 1 unit=10cm.

And while Maya/Max unit internally might be a cm, I regularly encounter scenes that are dm, meter or km set. It really depends on the scale on your scene.
A car, cm's
Solar system, big units! ;-)

[Bullit]

Well the physics scale in Soft is fixed so the only alternative is to change in the others.

[RichardCulver]

OK, Thanks for the replies.

So is anyone doing sims in Soft for use in Maya? If so, what scale are you using on the Maya and the Soft side?

[Mathaeus]

Not direct answer but anyway - once you have cached point cloud, you can just scale appropriate attributes before exporting, like point position, point velocity, particle size.... using ICE tree, applied over the cached point cloud.

BTW, in Max, changing the units, by some tradition, works correctly with static stuff, that's all. For Biped or CAT, if units between two scenes doesn't match, then you're searching the internet for some multiple steps procedure...

[RichardCulver]

Interesting solution. I was starting to think something along those lines. Scaling the cached sim after the fact. But I had not thought of doing it in the ICE tree as you describe. I'll keep that in mind. Thanks.