Categories/Attributes Approach Question

Hi Guys,
I'm trying to work out using nop how to solve a navigation problem I'm having..

What i'd like in my sidenav permanently is the following menu:

Style
    Rings
    Necklaces etc

Material
     Silver
     Gold

etc

Color
    Red
    Green
    Blue


So products have a style category, a material category and a colour category

What id like is this sidenav down the side and then the scenario would be:

1. a user clicks on a style...then i'd love for all the colours and materials to appear as ajax filters for that style..
2. a user clicks on material then all the styles and colours for that material appear
3. a user clicks on colour, then all the styles and materials for those colours appear as filters

Please see attached the screen shot called style, material, colour for what im trying to achieve..

would you suggest that I have a category called material and a category called color or try and generate the menus for those by finding all attributes called colour.. for all products for the selected category..

So basically what im trying to do is when you select a category.. find all other category children and use them as filters on the products.. (maybe im thinking about it wrong and they need to be attributes)

But either way i wanted all the child menu items to appear as filters even if there's nothing in them..


http://i812.photobucket.com/albums/zz50/mollythemoggie/nop/Colour_Red_Category_1.jpg
http://i812.photobucket.com/albums/zz50/mollythemoggie/nop/Material_Silver_Category_1.jpg
http://i812.photobucket.com/albums/zz50/mollythemoggie/nop/Style_Necklaces_Category_1.jpg

Any help would be very very much appreciated.

Thanks,
Tom

I was thinking and have been thinking about this all night! DAMN! head is spinning trying to work this one out!

I was wondering on the product/category listing pages whether i should do something like

GetBreadCrumb  - retrieve the parent category for the current category

then for each product currently in the datalist iterate over and get the result of

GetProductCategoriesByProductId - where category not in the result of GetBreadCrumb


then... find the parent i'ds in that result and iterate over to generate the category filter boxes for categories that are not descendants of the current category but are descendants of any other parent categories where the products on screen are a member of..

hmm i dunno if im overcomplicating this or if this approach is sound!



I think in laymans terms what im trying to find is all categories that a product belongs to that aren't the current category and group by parent category

ie if the categories are

Style
   Earring
   Ring
   Necklace


Material
   Silver
   Resin
   Leather

Colour
   Black
   White
   Red
   Green

I have highlighted the categories a product belongs to

so when the user is in style the lists i'd like to generate are

Material: Silver

Colour: White, Green


when the user is in Colour, the lists id like to generate are
Style: Ring

Material: Silver


when the user is in Material, the lists i'd like to generate are
Style: Ring
Colour: White, Green