Double sided polygon shading

[pimk]

hi how can i do what is call a double sided material in 3d smax in maya?
tanxs

[empleh]

Look up "double-sided shading" in the help docs, the process is outlined there.

ww

[pimk]

i doesnt work il real time,i need it for a polygon in real time

[sibben]

Duplicate face (separate checkbox off) -> Edit Polygons -> Normals -> Reverse. That's if your engine/exporter does not handle double sided faces in some other way.

[pimk]

that not the answer to the problem ,it is not a question of duplicating geometry and game exporting.

[joojaa]

Well in that case you need to dig in the api im afraid!

[pimk]

i just want to do a double sided shader like in 3dsmax!!!
how can i do this ,thanxs

[joojaa]

Yes well you can do it for the renderer but not for the open gl views. Read the online (hit f1) manuals on this its pretty easy, and well explained.

You can do a you do a history hookup with a reversed copy (remeber to set backface culling on for the views). This can well work as a proxy for you... and then just do the real thing on export time if thats what you want to do.

[pimk]

sorry joojaa i dont understand , please help!!!!!

[sibben]

I don't understand what you want. The manuals describe how to make a double sided shading network...

For real time? Are you going to export it to a game?

[pimk]

yes i want it for real time and by now im not goin to export it ,just want to look at it in maya and take some screens grab for my demo, but i still dont find the way to do it,in the library they explain double sided shadind but it doesnt work in open gl. (in 3dsmax its possible to do a double sided shading and look at it in realtime so in maya im sure it can be done )
help, thanks

[sibben]

The easiest way by far is to duplicate and flip the polygons. That way you can assign any shader you like to the different sides. Enable Backface Culling from Custom Polygon Display to make them easy to select too.

[pimk]

ok, anyway its for real time games so to duplicate those faces its not good and in my case it doesnt suit to the geometry of the object ,i think its an alias wavefront lack this implemantion should exist just like on 3dsmax

[joojaa]

If you only want to preview it then its a good way off doing it.. When you have the history intact it will even follow the object... try it!

But yeah you couldnt export this directly... only sad thing. But maya isnt max! theres lots of things max should implement!

[joojaa]

ok heres one wa that works in maya 4.5 just (no need to turn culling on. Its not finished yet so you still need to assign the reverse node thats parented to the original a surface and it issues warnings (didn thave the time to fix), also reference the copy.

and merry chrstmas.

// doubleSidedOGL ver 0.1
// joojaa 2002
// use at own risk!
// needs possibility for material connection and
// setting child as reference
global proc doubleSidedOGL(){
string $selection[];
string $item;
$selection = ls -sl -dag -type mesh -type nurbsSurface;
if(size($selection)==0){
print "please select nurbs or poly surfaces";
return; //if nothing suitable selected end now
}
for ($item in $selection){
setAttr ($item +".doubleSided") 0;
createNode "mesh" -n ($item + "_reverse"); //-p $item;
connectAttr -f ($item + ".outMesh") ($item + "_reverse.inMesh");
parent -r ($item + "_reverse") $item;
setAttr ($item +"_reverse.doubleSided") 0;
setAttr ($item +"_reverse.opposite") 1;
}
}

have fun!

[sibben]

Alright, now I am telling you for the last time...

If you just want to make screenshots or look at it in Maya duplicating the faces is the way to go.

Select the face, use duplicate face and reverse the normals. Now you have two polys facing opposite directions. Assign them different shaders and that's it. If you want to render it go ahead - it should work fine.