Material/uv details disappear after merge

[donburisan]

Hi guys,

I have multiple polygons modelled, uv-ed and material-ed. But when I merge them (All under the same obj level), some uv and materials does not pass through.

I've checked help about merge asking me to "set explicitly" but I'm really lost what it means as everything has been set.

Any help or advice will be appreciated.

Thanks!

[anim]

maybe I don't understand what you mean exactly but let me try

when you are merging several geometries the result will contain all attributes from all of them

if an attribude doesn't exist on any of the input geos a default value will be used for those points/prims/... (and warning on merge sop will be displayed)

if they contain the same attribute but different class (point/vertex/prim/...) then both will be created and you may for example find out that your resulting mesh contains vertex 'uv' and point 'uv' as well, but during rendering only vertex uvs will be used since the lower level is always preferred and this may be part of your problem, which can be solved by promoting all uvs to vertex prior to merge sop

are you using combine shelf tool to merge them all?

in that case be careful about object level materials, since you will loose all or all except one since you are merging it into new obj, in that case it's better to assign materials on sop level or work with overrides and one material

[donburisan]

Thanks. All geometries are built within a single object >> this is called the sop level correct?

I finally found the problem: i actually uv-ed different geometries and when merged I must have missed out something so Houdini chose only 1 of the uv.

I'll just do the uv after the merge instead of before.

Still, it is nice to learn new things. Do you have any tutorials suggestions to learn about class and attributes?

quick google tells me they are total alien from maya and max. they also seem to be 1 of the reasons to tap Houdini's power.

[ben]

If you are looking for something about attributes, variables, etc... this one is a must :

http://www.sidefx.com/index.php?option=com_content&task=view&id=1500&Itemid=254

[donburisan]

thanks a lot. that'll be in my training list for winter holidays.