It seems to me that some sample DAE files from the model bank have complete transparent materials, so they are invisible. (Seymour.dae and files in the Skinning_ID_SID_Test)
Are they correct content?
If so, how can I render them to be visible?
<transparent>
<color>0 0 0 1</color>
</transparent>
<transparency>
<float>0</float>
</transparency>