Converting Vray MEL to Python

[Intuition]

I've been going back through the Vray toolkit I made for myself and trying to convert it from the original MEL into Python

I am having trouble with the formatting since I am trying to copy from web examples of Python which rarely have Vray specific command examples.

So, for instance I have a standard apply Vray Subdivision to all items selected (avoiding the menu repeats). ANother that adds oth SubD and disp control etc etc. A remove all script and so on.


Here is the add Vray SubD In it's MEL form. It also applies the settings at the bottom.

string $mySelection[]= `listRelatives  -shapes`;

print $mySelection;

for ($object in $mySelection){
    
    vray addAttributesFromGroup $object vray_subdivision 1;
    vrayAddAttr $object vraySubdivEnable;
    vrayAddAttr $object vraySubdivUVsAtBorders;
    vrayAddAttr $object vraySubdivUVs;
    vrayAddAttr $object vrayStaticSubdiv;
    vray addAttributesFromGroup $object vray_subquality 1;
    vrayAddAttr $object vrayOverrideGlobalSubQual;
    vrayAddAttr $object vrayViewDep;
    vrayAddAttr $object vrayEdgeLength;
    vrayAddAttr $object vrayMaxSubdivs;

    vray addAttributesFromGroup $object vray_displacement 1;
    vrayAddAttr $object vrayDisplacementNone;
    vrayAddAttr $object vrayDisplacementType;
    vrayAddAttr $object vrayDisplacementAmount;
    vrayAddAttr $object vrayDisplacementShift;
    vrayAddAttr $object vrayDisplacementKeepContinuity;
    vrayAddAttr $object vrayEnableWaterLevel;
    vrayAddAttr $object vrayWaterLevel;
    vrayAddAttr $object vray2dDisplacementResolution;
    vrayAddAttr $object vray2dDisplacementPrecision;
    vrayAddAttr $object vray2dDisplacementTightBounds;
    vrayAddAttr $object vray2dDisplacementFilterTexture;
    vrayAddAttr $object vray2dDisplacementFilterBlur;
    vrayAddAttr $object vrayDisplacementUseBounds;
    vrayAddAttr $object vrayDisplacementMinValue;
    vrayAddAttr $object vrayDisplacementMaxValue;

setAttr ($object+".vrayMaxSubdivs") 4;
setAttr ($object+".vrayEdgeLength") 4.0;

}

print("Applied All Vray SubDivision");

So I am trying to begin converting this to Python...

Right off I am having trouble with the commands usage, arguments, what belongs in quotes, and ordering. Mainly because I don't see many example usages like you can get in the MEL or Python pages at Autodesk.

import maya.cmds as mc


mySel = mc.listRelatives(s=True)
print mySel


for i in mySel:
    mc.vray("addAttributesFromGroup", mySel[i], "vray_subdivion", 1)
    mc.vray("AddAttr", mySel[i], "vraySubdivEnable")
    mc.vray("AddAttr", mySel[i], "vraySubdivUVsAtBorders")
    mc.vray("AddAttr", mySel[i], "vraySubdivUVs")
    mc.vray("AddAttr", mySel[i], "vrayStaticSubdiv")
    mc.vray("addAttributesFromGroup", [i], "vray_subquality", 1)
    mc.vray("AddAttr", mySel[i], "vrayOverrideGlobalSubQual")
    mc.vray("AddAttr", mySel[i], "vrayViewDep")
    mc.vray("AddAttr", mySel[i], "vrayEdgeLength")
    mc.vray("AddAttr", mySel[i], "vrayMaxSubdivs")

Now, there is usage examples for Vray addAttributesFromGroup, but there isn't for simply Vray AddAttr.

In some places I found usage examples that don't look for =True or False.

Like this. From https://github.com/BigRoy/mayaVrayCommandDocs/wiki

vray("addAttributesFromGroup", node, attrGroup, state)

But when I use just this line (note I changed the =True to 1 and put the vray_subdivision in quites)... instead of the whole loop.

import maya.cmds as mc


mySel = mc.listRelatives(s=True)
print mySel

for i in mySel:
    mc.vray("addAttributesFromGroup", mySel[i], "vray_subdivion", 1)

It doesn't error out or tell me my usage needs more arguments.... it simply tells me

# Error: addAttributesFromGroup: node [u'pSphereShape1'] not found. #

So, my Python formatting isn't correct of course. I'm either not formatting the Vray commands in brackets/quotes, commas, correctly. OR the way it is applying the shape node into the brackets is incorrect.

Thanks. I've done quite a few conversions of my old MEL scripts into Maya simply following usage examples and just need some Vray specific help.


---EDIT---- OK I changed the [i] to mySel[i] for the iterations. But now it is telling me....

list indices must be integers, not unicode #

[Intuition]

Hah ok I figured it out..

I had a spelling error and then was also misusing the array/list by placing my whole variable "mySel" instead of the for loop variable "i" for the object. This works.

import maya.cmds as mc

for i in mySel:
    mc.vray("addAttributesFromGroup", i, "vray_subdivision", 1)
    mc.vray("addAttributesFromGroup", i, "vray_subquality",1) 
    mc.vray("addAttributesFromGroup", i, "vray_displacement", 1)

[Intuition]

Ok I can't seem to figure out the correct formatting for set a Vray attribute though

mc.setAttr (i,"vrayMaxSubdivs", 12)
mc.setAttr (i, "vrayEdgeLength", 0.001)

It gives me either an indentation error OR that the attribute doesn't exist.

[ivaylo.ivanov]

The Maya help says you should do:

mc.setAttr (i+".vrayMaxSubdivs", 12)

[Intuition]

DOh, Thank you.

.....of course, my MEL adds the two together in brackets, why didn't I see that?