[Atlas] crash when zooming out on a map

[serveurix]

I'm editing some maps with the last svn, and when I zoom out, Atlas segfaults at a certain level of zoom, with the following message:

ERROR: Failed to create VBOs (64*32827) ERROR: Failed to allocate VBO for vertex array Erreur de segmentation

Could this be related to: r16241 ?

Debian Jessie with Radeon R9 280X, Catalyst driver. Edit: happens with radeon too.

Update: When I'm moving the camera angle sometimes I get the error messages printed on screen, but no crash. I also have a shadow appearing all over the map under certain camera angles.

Update: The map on which I have the problem. Note that this map was created *before* the last VBO commit.

[Stan]

Could you provide a crashdump and system info ? :)

[Philip Taylor]

I thought I could get away with making the VBOs a bit smaller (2MB instead of 4MB) to reduce the wasted memory, but evidently I can't :-(

[Philip Taylor]

Hmm, actually I'm not sure that's really the problem... Even on a huge map like "Eire and Albion", I don't see any allocations larger than 64*10327, which easily fits within the 2MB limit, so I'm not sure what's causing such a huge allocation in this case.

It would probably be helpful to get a stack trace by running it in gdb - that should indicate where the allocation is happening. If it happens repeatedly on a particular map, it would be helpful to know which map (or get a copy if it's a custom map).

[Stan]

Maybe try on the unit display map.

[historic_bruno]

Here's some instructions on how to get a 0 A.D. crash backtrace on Linux: Debugging

[Niek]

Replying to serveurix: with what radeon does it happen too?

[Philip Taylor]

Looks like art/meshes/structural/pers_gardens_struct.dae has a crazy number of vertexes - normally 32410, and if you turn on preferglsl+gentangents it goes up to 32827. Each vertex takes 64 bytes in the VBO, so 32827 exceeds 2MB and it fails. I can increase the limit back up to 4MB. (Seems an excessively large mesh, though...)

[Stan]

It's because of all the plants on it, Enrique did a really good detail job on it.

[philip]

In 16309:

Increase max VBO size back to 4MB.

Some meshes (e.g. pers_gardens_struct with gentangents enabled) have >32K vertexes, and won't fit in a 2MB VBO. r16241 had reduced them from 4MB to 2MB. So just make the VBOs bigger again, and try not to worry about the waste of memory.

Fixes #3026, #3042.