Imagination PowerVR SDK Blog

PVRGeoPOD Exports Cube with 24 Indexed Vertices

pvrgeopod
pvrshaman

#1

Hi,





Using PVRGeoPOD on the Mac, I exported the default Blender cube as an indexed triangle list. Looking at the exported POD file in PVRShaman the mesh is flagged as indexed but has 24 vertices rather than the expected 8. Looking at the actual vertex data I see duplicate vertices even though it is indexed. I also looked at the box example that comes with the PVR SDK (TrainingCourse/33_ParallaxBumpMap/OGLES2/Box.POD). This file also has 24 vertices even though it is indexed.





Exporting from Blender to Collada (.dae) and using Collada2POD gives me the same results but if I export as an FBX then convert to Collada then convert to POD, I get the expected 8 vertices. Is there a reason for 24 vertices in the cube when using PVRGeoPOD with Blender?





Here are the versions of the software I am using:


- PVR SDK 2.10.86.3987


- Blender 2.62


- Mac OS X 10.7.3





If needed I can zip up the various files send them.





Thanks,


Mark


MarkMizuguchi2012-03-29 18:39:46


#2



Hi,
 
Are the vertices truly duplicated? Though the vertex positions may be duplicated I imagine that each "duplication" has a different normal which makes it its own vertex. In the case of a cube each corner is likely to have 3 different normals so you end up with 24 unique vertices on export.
 
As for converting from FBX I can only assume the normal data got lost somewhere.
 
Thanks,
 
Scott

Scott2012-04-02 16:05:01