iOS SceneKit: XCode "breaks" imported DAE material colors
First of all, I apologize if for the non-technical language regarding 3D design, it's out of my scope.
I'm using some DAE files for displaying 3D models on SceneKit, provided by a 3D designer. However when I add it to the scnassets folder on XCode, all material colors get "corrupted". Take for example this DAE for a jewel, the blue and white version is visualized on an online viewer and is the correct one. The other black and white is a screenshot I took from my phone running an ARSession with the dae loaded on a node.
Any idea on how I can preserve the original colors?
Update Running from the command line I get lots of this warnings:
$ xcrun scntool --convert ARO-E-BLING.DAE --output cliConverted.scn --format scn
Warning: The instance_effect with URL file:/Users/Leandro/Documents/ARO-E-BLING.DAE#White stone-fx does not reference an effect, skipping it
Warning: The instance_effect with URL file:/Users/Leandro/Documents/ARO-E-BLING.DAE#Blue Stone-fx does not reference an effect, skipping it
Warning: Found an invalid material [White], reverting to a default material
Warning: Found an invalid material [Blue], reverting to a default material
Well, running it from the command line helped me find the solution. It seems scntool fails if materials and/or effects in the dae have whitespaces on it. For instance I had things like:
<material id="Blue Stone" name="Blue Stone">
<instance_effect url="#Blue Stone-fx"/>
</material>
which I had to replace for
<material id="Blue_Stone" name="Blue_Stone">
<instance_effect url="#Blue_Stone-fx"/>
</material>
UPDATE Jan 8 2018 I submitted a bug report to Apple and they stated that this behavior is not a bug stating that:
According to the Collada spec (https://www.khronos.org/files/collada_spec_1_4.pdf) the URL of an "instance_effect" is of type "xs:anyURI".
URIs are not allowed to contain space, they must be escaped ("Spaces should instead be escaped using %20" in http://www.datypic.com/sc/xsd/t-xsd_anyURI.html).