Change gNormal on Shading pass

[Anonymous]

Hi,
I need to make a proxy material that will shade backfaces faces with the frontfaces shade.

I didn't find a way to do it with maxscript because I don't have access to shading.
So I've go with SDK.

May approach is to change the fragment normal so it will be inverted if it is a backface and then pass to correct Material shading, but I don't have access to gNormal.

It is possible to change somehow fragment normal before passing it to next Material Shade?

I need something in this style.

void maxProject2::Shade(ShadeContext& sc) 
{
 sc.GNormal = new Point3(-sc.GNormal().x,-sc.GNormal().y,-sc.GNormal().z)


 Mtl *sm1 = mapOn?submtl:NULL;
 if (gbufID) sc.SetGBufferID(gbufID)
...
}

[Anonymous]

Sorry found the answer... SetNormal()..

but the shading still don't want to interact as I want..
The polygon is just black.. if I switch the backFace the result is the same as original.

[Anonymous]

Done, I forget to make the material 2 sided...

but Can I fix the inside polygons smoothing? they are faceted.

this is my code:
if (sc.backFace) {
Point3 pt(-sc.GNormal().x,-sc.GNormal().y,-sc.GNormal().z)
sc.SetNormal(pt)
}


----------------------

Fixed....

if (sc.backFace) {
//Point3 pt(-sc.GNormal().x,-sc.GNormal().y,-sc.GNormal().z)
//sc.SetNormal(pt)
sc.backFace = false;
Point3 pt(-sc.V().x,-sc.V().y,-sc.V().z)
sc.SetView(pt)
}