What I mean is that if you attach the material by layer and several blocks have layers with the same name, when you insert the blocks in a drawing, then you only will see the material of the block that has been inserted first
(We are talking about polygonal mesh blocks-just to be sure we are still on same page)
What version of AutoCAD did this happen in - the dissapearing materials if duplicated in inserted blocks?
You do not mean in AutoCAD 2010?
If I insert 100 old blocks (even junky old r14 .dwgs and another set from r2006 .dwgs that I tested)
one - by -one (All these blocks have Materials Attached By Layer in original files and many
blocks have the same Layer name and same Material attached to the same Layer name.
you enter the "convertoldmaterials"
command at the prompt and enter.
The Materials palette is populated with all the materials and
there ARE NO DUPLICATES.
All the blocks render perfectly.
There is still the single RM_SDB block in the current 2010 .dwg file.
And AutoCAD will not allow it to be purged - so I assume it still has a function.
In the Attach By Layer dialog they mats are in alphabetical order.
In the same dialog now you can click on the Mat or Layer Attachment name column header
and sort alphabetically.
I do not remember what autocad 2007,08, or 09 did....
I have to reload them.
Prior to this
I had the OPPOSITE problem from what you describe historically:
When Acad 2006 came out (please tolerate gaps in my Acad version-while I was living in a cave).
I insert many r14 blocks with mats assigned By Layer-
with many blocks having the same Layer and same material assigned to the Layer.
Just like above:
Layer-brown with brown mat attached
Layer-blue with blue mat attached
Layer-red with red mat attaced etc. ad nauseum
so of course many blocks will have the same Layers name and the same color/material attached.
If I insert all of those into Acad r2006-
All the materials are duplicated for each insertion.
and given a *1,*2,*3 suffix in Render Materials(Acad 2006 still had old Render)
The same thing happened with AutoCAD r2006 Blocks with Mats assigned by Layer and
inserted into AutoCAD r2006 and render.
If I export the blocks to an atttibute Table I could see the RM_SDB
carried all the definitions-
In the .dwg,
I could purge the duplicates but if I saved the Target file - they would all be back the
next time I open the file. A *material List* 1*2*3* mess in addition to the already mess of all the Layers named for Materials.
But AutoCAD 2010 does not have this particular problem.
The bigger issue is what you describe-
the whole strategy and plans for BIM and 3d models- the display issues.
But that is another issue -
Right now I simply am dying to understand what this dissapearing block material behavior you descibe is....
Thank you for your time
I wish I had your email to send you files.
I went through autodesk SEEK and other places to try and find any furniture etc that has 2010 .dwg 3d models-
but the file formats there are all over the place.
If I were downloading from a manufacturer's catalogue it would be a good thing to see
a separate version beginning with AutoCAD 2010...
then those ideas from Bill Gillis about converting entites would not be so cumbersome.
He has alot of other historic posts about this too....
But as he noted even after conversion there are limitations for legacy polyface meshes in 2010.
The editing in 2010 is limited.
But it sounds like you do not need to edit the models-
just get the materials to render.
I can find no news about support for polyface meshes in updates or such...
But your original post was the only thing on the web I found about the original issue.
So once again I thank you with all my heart for saving me much more waste of time.
Any manufacturer is lucky to have you.
Many of them seem very proud when they release
new model collections for BIM and such in the current time.
I hope the company for whom you are providing the library will fund a new collection-
if the render by Entity does not happen.
Thanks again for all your time explaining this.