Re: [Maya2osg-users] Discussion of next changes

[Jean-Sébastien G. <jea...@cm...>]

Hi Javier, Peter,

Thanks a lot for the discussions! My intent when I sent my message on 
Saturday was just to explain what I had in mind and maybe get a few 
ideas, I didn't want you to start doing anything in my place! :-)

>    Well. We should know what does J-S exactly needs, but I was thinking
> that if the target is to replace the Maya2OSG shader with a custom
> one, Maya node attributes could contain the information indicating
> that this custom shader must be used and the extra information needed
> for the shader. In any case, when you reach a bump2D node you already
> have the shader half created, thats why I didn't see it. But of course
> a previous traversal can be done in the shading network to check for
> the attribute.

My idea was to simply store the information needed (normal map texture 
filename, bump amount) somewhere, which could be read by our engine at 
file load time. I cannot generate the shader at export time, as our 
products generally use different shaders... So we just need to store the 
information somewhere appropriate (osg::Material or osg::StateSet 
description list for the normal map stuff, for example) and our engine 
will do the rest.


>    Mmm... I still think we are mixing too much things there. I'd prefer
> the custom attributes approach. I don't know what you mean with
> "create some new window". You can create attributes without any new
> development, just in the Attribute editor with Attributes>  Add
> attributes... option. And it is quite easy to manage from MEL:
>
> addAttr -ln "normal_map"  -at double  |pSphere1;
> setAttr -e-keyable true |pSphere1.normal_map;
>
>    Or course, once you have designed the attributes you need, you
> should develop the artists tools to automate this (maybe just some
> shelf buttons).
>

I was actually thinking we don't need anything special in Maya. The 
plugin would just see that the Maya material has a Bump2D node attached 
to the bump attribute, and would add a string in the description at the 
appropriate place (as I said, osg::Material or osg::StateSet) with a 
special tag saying that this is metadata. Something like:

maya2osg NormalMap filename:<some filename>.jpg bump:30

As I said, our engine would then parse this when loading the .osg file 
and load the normal map and appropriate shaders.

>> So, this is done, a first draft, Pre Post Export Mel and Preview Mel. Pre
>> and
>> Pre and Post will substitute $path to filepath, $file to filename and $type
>> to filetype

That's great, it will be very useful to us! Thanks!

>    I think this discussion would be much more productive with some
> usage examples and so we can work on several prototypes to see which
> one we like most.

I can give you some examples of what I would like, but I hope the 
description I gave above makes what I had in mind clearer.

>    I'll take a look at it ASAP. Right now my daughters are dragging me
> out of home. Quite a challenge was to be able to answer this message!
>   :)))

I understand, I have 3 boys myself :-)

Thanks for your help,

J-S
-- 
______________________________________________________
Jean-Sebastien Guay    jea...@cm...
                                http://www.cm-labs.com/
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