Shared geometry meshes disappearing on 915GM

[jimmy-talbot]

Hello,

We are using the Ogre graphics library (www.ogre3d.org) as part of our application. We noticed that, when running on an integrated Intel graphics adapter (915GM), some meshes were disappearing (but when running on NVidia/ATI hardware, the meshes showed up fine).

I attach a zip file containing a mesh and a mesh viewer. Loading the mesh viewer on an ATI/NVidia card shows the mesh fine, but running the same on a 915GM doesn't show the mesh.

We later figured out that when meshes are exported (from Maya to Ogre) with Use shared geometry disabled (see http://wiki.projectredtail.com/index.php/Help:Maya#Mesh_Export_Steps), then the meshes do show up fine on the 915GM.

Cananybody give me more information about why that setting would cause the meshes not to show up on the 915GM? Is there a good way to diagnose that kind of issues? We figured out the setting by trial& error -- not the most efficient way.

Also, couldanybody tell me which Intel variant would be best to test on? For example if a platform other than 915GM had more restrictions, then maybe we shouldnt bother testing on the 915GM platform at all, and just focus on the more restrictive platform. I guess it would be useful to have a chart in terms of the capabilities of all the Intel integated graphics cards, so that we could pick our minimum requirements, and thereby whichconfigurations to focus our testing on.

Thanks

Jimmy Talbot

[jimmy-talbot]

Woops -- I couldn't include the mesh viewer itself in my attachment, it was too big. The mesh viewer can be downloaded from http://www.ogre3d.org/index.php?option=com_content&task=view&id=413&Itemid=133-- either the lexi viewer or the CEGUI Mesh Viewer exhibit that behavior.

[Chuck_De_Sylva]

Just to follow up so others know, the issue was that the Mesh Viewer was using 32 bit indices, which are not supported on 915 and 945. They are on 965. But you have to use 16 bit indices on the later two. Unfortuneatly it doesn't look like the source to the Ogre Mesh Viewer is public so we can fix that.