COLLADA_PBR Extension

COLLADA_PBR.xml

<extra>
  <ext name="pbr">
    <metallic_roughness>
      <metallic>
        <factor>FloatOrParam</factor>
        <bind_tex ref="texture-0" channel="G" />
      </metallic>
      <roughness>
        <factor>FloatOrParam</factor>
        <bind_tex ref="texture-0" channel="B" /> 
      </roughness>
    </metallic_roughness>
    <albedo>
      <tex ref="sampler0" />
      <color>1 1 1 1</color>
    </albedo>
  </ext>
  
  <ext name="normalmap">
    <tex ref="texture-1" />
  </ext>
  
  <ext name="occlusionmap">
    <tex ref="texture-2" />
  </ext>
</extra>