vrscene max-maya and vice versa, issues

[robin_lawrie]

doing a collab project with a maya studio, and using vrscene to share assets. for the most part it works, but we have noticed that most of the dirt and weathering effects in my materials are not coming across. we are usure exactly why, but one theory is the bias controls in vraydirt, used to drag the dirt towards ground (streaks etc)

given that max is z-up and maya is y-up, could this be the cause? can anyone suggest a fix? maybe something global using "override snippet?" if so id need someone cleverer than me to suggest a snippet, never even used it..

another issue is , when rendering a vrscene from them, i am unable to assign any kind of ID so its included in a multimatte... what is the correct workflow for this? do they need to assign objectID in maya before sending?

[hermit.crab]

given that max is z-up and maya is y-up, could this be the cause?

Spot on. Try the following code in the snippet, where you switch the Z and Y values of the bias. It will affect all VRayDirt maps.

TexDirt <*>{
bias_y=0;
bias_z=0;​
}

another issue is , when rendering a vrscene from them, i am unable to assign any kind of ID so its included in a multimatte... what is the correct workflow for this? do they need to assign objectID in maya before sending?

You can manually add ObjectIDs in the .vrscene itself (Snippet Overrides cannot add stuff), however, it would be easier if it's done prior export.

[robin_lawrie]

thanks that sounds great, so, that snippet will switch all of the z values to the y values of the vraydirt biases, and vice versa? seems too simple to do that

[hermit.crab]

thanks that sounds great, so, that snippet will switch all of the z values to the y values of the vraydirt biases, and vice versa? seems too simple to do that

Yes. However, if different VRayDirt maps have different biases, you should do one for each VRayDirt individually. Check the names in the .vrscene (should be TexDirt <name>).

[robin_lawrie]

ok, yeah thats quite fiddly in the end.. given the idea of vrscene is cross-compatibility maybe this could probably be considered a bug? vray should compensate for the variations in up-axis between diff dccs.... tbh ive not had time to confirm that this is actually the issue, too busy.. but maybe you confirmed above with your "spot on"

all i can confirm 100% is the ageing effects in the materials are not present, or barely, when i go from max to maya, which is obviousy, not desired behavior.