Sketchup validation vs. OpenCollada validation

When validating my .dae files using the OpenCollada validator, I am successful. However, upon trying to import the same .dae into SketchUp, I receive an error. Subsequently, I am given the option to open it, which is successful. The error in SketchUp is as follows:

“The .dae or .kmz file you are attempting to import cannot be validated. Your file may import just fine but there is a possibility SketchUp could import it incorrectly or even crash.”

Does anyone have any ideas what distinguishes the SketchUp validator from the OpenCollada validator?

I have attached the .dae file so you might try it yourself. It is valid against the Collada 1.4.1 Schema.

Seems to load fine in SketchUp 8.

I am also using Sketchup 8 and I can load the collada file, but I still get a message that says the file is improperly formed. Like I said above, I can ultimately import the geometry, but I am confused at why this message appears. Can you indicate to me why I get this message?

I don’t know about SketchUp’s validator so I’ve asked someone at Google to respond.

On my Macbook, I get the following validation error with xmllint:

$ xmllint --version --noout --schema collada.dae 

/usr/local/bin/xmllint: using libxml version 20708
   compiled with: Threads Tree Output Push Reader Patterns Writer SAXv1 FTP HTTP DTDValid HTML Legacy C14N Catalog XPath XPointer XInclude Iconv ISO8859X Unicode Regexps Automata Expr Schemas Schematron Modules Debug Zlib 
collada.dae:33: element transparent: Schemas validity error : Element '{}transparent': Missing child element(s). Expected is one of ( {}color, {}param, {}texture ).
collada.dae fails to validate

This means that on line 33 of your document, there is an empty element that must not be empty:

            <transparent opaque="RGB_ZERO" />

The Sketchup validator uses the 1.4.1 schema and tinyxml as the library that takes the schema and compares it to the current file.

When I run xmllint, I see the same Element empty error that Mark has described in his post. If you do not want SketchUp to validate a .dae file before importing you can un-check the ‘Validate COLLADA file’ check-box under the Options in the Import Dialog for COLLADA files.

hope this helps.

Hey guys,

xmllint was exactly the tool I was looking for! Thanks a lot for the support on this one! One baby step closer to a good Collada exporter!

Now that I am aware of this, why does anyone even suggest the OpenCOLLADA validator? Does it have any advantage over using xmllint and the schema?

Thanks again!


Validation is done at the XML level. XML instance documents, i.e. COLLADA .dae documents, are validated against either a DTD or schema (XML Schema, RELAX NG, etc.) by any XML validating parser (libxml2, tinyxml, expat, xerces, MSXML4, MSXML6, etc.). I.e. you don’t need COLLADA software to validate documents.

It’s all the same minus differences in software versions and bugs. You want to use newer software to get the best results. For example, older versions of libxml2 have a bug that prevents them from validating with the COLLADASchema.xsd schema.

Btw OpenCOLLADA/COLLADAValidator uses libxml2 so make sure to update your libxml2 installation.

I use an interactive windows tool that I hacked from a Microsoft open source project - XML notepad. I like the interactivity, editing, and the graphical browsing (see attached image). It also has a XLS processor, search…

You can get it at

for more information about all the XML tools available and their application to COLLADA, please read chapter 9: a COLLADA toobook from AK Peters ‘Game Development Tools’ book. … 568814321/

  • Remi

thanks for the xmlmint tip, I have actually used liquid xml editor but its not free so always good when you can get it for free! :lol: