How to get a geometry from a COLLADA (.dae) file with SceneKit - geometry

Question

I need to read the <geometry> in a COLLADA file in order to create the array of morph targets and animate the mesh from the base geometry to the target geometries.
I can only access the geometry from the base geometry that's embedded in the Node (the COLLADA file only have one <node>):
planeNode.geometry = scene!.rootNode.childNodeWithName("Plane", recursively: true)!.geometry
Here's the full source code of the COLLADA file (have 3 geometries and 1 node but only get access to 1 geometry):
<?xml version="1.0" encoding="utf-8"?>
<COLLADA xmlns="http://www.collada.org/2005/11/COLLADASchema" version="1.4.1">
<asset>
<contributor>
<author>Blender User</author>
<authoring_tool>Blender 2.77.0 commit date:2016-04-05, commit time:18:12, hash:abf6f08</authoring_tool>
</contributor>
<unit name="meter" meter="1"/>
<up_axis>Z_UP</up_axis>
</asset>
<library_images/>
<library_geometries>
<geometry id="Plane-mesh" name="Plane">
<mesh>
<source id="Plane-mesh-positions">
<float_array id="Plane-mesh-positions-array" count="12">-1 -1 0 1 -1 0 -1 1 0 1 1 0</float_array>
<technique_common>
<accessor source="#Plane-mesh-positions-array" count="4" stride="3">
<param name="X" type="float"/>
<param name="Y" type="float"/>
<param name="Z" type="float"/>
</accessor>
</technique_common>
</source>
<source id="Plane-mesh-normals">
<float_array id="Plane-mesh-normals-array" count="3">0 0 1</float_array>
<technique_common>
<accessor source="#Plane-mesh-normals-array" count="1" stride="3">
<param name="X" type="float"/>
<param name="Y" type="float"/>
<param name="Z" type="float"/>
</accessor>
</technique_common>
</source>
<vertices id="Plane-mesh-vertices">
<input semantic="POSITION" source="#Plane-mesh-positions"/>
</vertices>
<polylist count="2">
<input semantic="VERTEX" source="#Plane-mesh-vertices" offset="0"/>
<input semantic="NORMAL" source="#Plane-mesh-normals" offset="1"/>
<vcount>3 3 </vcount>
<p>1 0 2 0 0 0 1 0 3 0 2 0</p>
</polylist>
</mesh>
</geometry>
<geometry id="Plane-mesh_morph_Key1" name="Key1">
<mesh>
<source id="Plane-mesh_morph_Key1-positions">
<float_array id="Plane-mesh_morph_Key1-positions-array" count="12">-1 -1 0 1 -1 0 -1 1 0 1 2 0</float_array>
<technique_common>
<accessor source="#Plane-mesh_morph_Key1-positions-array" count="4" stride="3">
<param name="X" type="float"/>
<param name="Y" type="float"/>
<param name="Z" type="float"/>
</accessor>
</technique_common>
</source>
<source id="Plane-mesh_morph_Key1-normals">
<float_array id="Plane-mesh_morph_Key1-normals-array" count="6">0 0 1 0 0 1</float_array>
<technique_common>
<accessor source="#Plane-mesh_morph_Key1-normals-array" count="2" stride="3">
<param name="X" type="float"/>
<param name="Y" type="float"/>
<param name="Z" type="float"/>
</accessor>
</technique_common>
</source>
<vertices id="Plane-mesh_morph_Key1-vertices">
<input semantic="POSITION" source="#Plane-mesh_morph_Key1-positions"/>
</vertices>
<polylist count="2">
<input semantic="VERTEX" source="#Plane-mesh_morph_Key1-vertices" offset="0"/>
<input semantic="NORMAL" source="#Plane-mesh_morph_Key1-normals" offset="1"/>
<vcount>3 3 </vcount>
<p>1 0 2 0 0 0 1 1 3 1 2 1</p>
</polylist>
</mesh>
</geometry>
<geometry id="Plane-mesh_morph_Key2" name="Key2">
<mesh>
<source id="Plane-mesh_morph_Key2-positions">
<float_array id="Plane-mesh_morph_Key2-positions-array" count="12">-1 -1 0 1 -1 0 -1 1 0 2 1 0</float_array>
<technique_common>
<accessor source="#Plane-mesh_morph_Key2-positions-array" count="4" stride="3">
<param name="X" type="float"/>
<param name="Y" type="float"/>
<param name="Z" type="float"/>
</accessor>
</technique_common>
</source>
<source id="Plane-mesh_morph_Key2-normals">
<float_array id="Plane-mesh_morph_Key2-normals-array" count="3">0 0 1</float_array>
<technique_common>
<accessor source="#Plane-mesh_morph_Key2-normals-array" count="1" stride="3">
<param name="X" type="float"/>
<param name="Y" type="float"/>
<param name="Z" type="float"/>
</accessor>
</technique_common>
</source>
<vertices id="Plane-mesh_morph_Key2-vertices">
<input semantic="POSITION" source="#Plane-mesh_morph_Key2-positions"/>
</vertices>
<polylist count="2">
<input semantic="VERTEX" source="#Plane-mesh_morph_Key2-vertices" offset="0"/>
<input semantic="NORMAL" source="#Plane-mesh_morph_Key2-normals" offset="1"/>
<vcount>3 3 </vcount>
<p>1 0 2 0 0 0 1 0 3 0 2 0</p>
</polylist>
</mesh>
</geometry>
</library_geometries>
<library_controllers>
<controller id="Plane-morph" name="Plane-morph">
<morph source="#Plane-mesh" method="NORMALIZED">
<source id="Plane-targets">
<IDREF_array id="Plane-targets-array" count="2">Plane-mesh_morph_Key1 Plane-mesh_morph_Key2</IDREF_array>
<technique_common>
<accessor source="#Plane-targets-array" count="2" stride="1">
<param name="IDREF" type="IDREF"/>
</accessor>
</technique_common>
</source>
<source id="Plane-weights">
<float_array id="Plane-weights-array" count="2">0 0</float_array>
<technique_common>
<accessor source="#Plane-weights-array" count="2" stride="1">
<param name="MORPH_WEIGHT" type="float"/>
</accessor>
</technique_common>
</source>
<targets>
<input semantic="MORPH_TARGET" source="#Plane-targets"/>
<input semantic="MORPH_WEIGHT" source="#Plane-weights"/>
</targets>
</morph>
</controller>
</library_controllers>
<library_visual_scenes>
<visual_scene id="Scene" name="Scene">
<node id="Plane" name="Plane" type="NODE">
<matrix sid="transform">1 0 0 0 0 -4.37114e-8 -1 0 0 1 -4.37114e-8 0 0 0 0 1</matrix>
<instance_geometry url="#Plane-mesh" name="Plane"/>
</node>
</visual_scene>
</library_visual_scenes>
<scene>
<instance_visual_scene url="#Scene"/>
</scene>
</COLLADA>
Any help is appreciated. Thanks!

Answer 1

you can use entryWithIdentifier:withClass: to retrieve objects that are not in the scene graph. Alternatively, in your authoring tool, you can attach the morpher to a node and then use the morpher property of a node to retrieve its target geometries.