There is several instances of the lightmap shader. Some parameters values of the shader need to be different "per shader instance", and others, like the path of a directory where to put the all lightmaps maps, need to be the same for each shader instances.
For the moment, I put a single UserDataBlob nested in a single null X3dObject in the Softimage scene, and in the the shader's code, I recurse down the scene db over all miInstance until the UserDataBlob with correct ID is found. If you have a simpler solution ... would be good. 2012/9/25 Daniel Brassard <dbrassar...@gmail.com> > Instances in MR inherit from the main shader declaration/definition > itself. Is the custom lightmap shader only used once in the Softimage scene > and all instance inherit from the lightmap or is each instance of the > lightmap has it's own UserDataBlob? > > On Tue, Sep 25, 2012 at 9:51 AM, Rémi Arquier <arqu...@gmail.com> wrote: > >> Hi Daniel, Yes it looks like it is by design. But note that the Scene >> Root derive from a X3DObject. >> I think the UserDataBlob is exported for scene elements which generate >> leaf instances only. >> >> I just need to export global data for a custom lightmap shader, all >> shader instances need that same data, and I don't realy know where to put >> it on Softimage side. Nothing very exciting. >> >> As you seem aware of thoses things, how do you do when you need a global >> parameter for a given shader, regarding the spdl parameters ? By "global", >> I mean that all shader instances would share the same parameter' value, and >> if I would change the value using one of the spdl interface of one shader >> instance, the others values of the other parameter instances would change >> also. You see what I mean ? >> >> Rémi >> >> >> 2012/9/25 Daniel Brassard <dbrassar...@gmail.com> >> >>> I think it is by design unfortunately, Rémi, >>> >>> This feature is only available when the UserDataBlob is nested directly >>>> under a >>>> Camera<http://download.autodesk.com/global/docs/softimage2013/en_us/sdkguide/si_om/Camera.html> >>>> , >>>> Light<http://download.autodesk.com/global/docs/softimage2013/en_us/sdkguide/si_om/Light.html> >>>> or >>>> X3DObject<http://download.autodesk.com/global/docs/softimage2013/en_us/sdkguide/si_om/X3DObject.html> >>>> . >>> >>> >>> What I wish would be an ICE UserDataBlob node that we could feed >>> anything we want to it! >>> >>> It look like you are thinking outside the box to have a need for >>> userdatablob on scene root! I'm curious! >>> >>> On Tue, Sep 25, 2012 at 5:19 AM, Rémi Arquier <arqu...@gmail.com> wrote: >>> >>>> Hi list >>>> >>>> I don't know if it is a bug or not, but when I put a renderable >>>> UserDatablob on the Scene Root, I cannot get it back in my Mental Ray >>>> shaders. I looked into the miArchive and I don't see it (I see it when it >>>> is attached to an other X3DObject like object/cam/light, but not when >>>> attached on the scene root). >>>> >>>> Is it normal ? I find it sad since it would be a good place for placing >>>> global data for shaders. >>>> >>>> cheers >>>> >>>> Rémi Arquier >>>> >>>> >>> >> >
