[osg-users] OSG + Qt performance issue

[Ale Maro]

Hi all,

we recently updated our project from OSG 3.4.0 + Qt 5.5 to OSG 3.6.0 + Qt 5.11.
We noticed a framerate slowdown without changing our code.

After some investigation we found that using VBO as we did until now the performance is bad but using display lists performance are equal or better than before.

The bottleneck seems to be in Draw step (in my test using VBO on screen statistics shows Draw timing greater than 100 since other timings are 0.3)

We choose to use VBO in the past becouse we potentially have very big geometries in a single node so choosing VBO we can increment visualization performance at first frame and avoid memory problems.

Now we saw very different code inside Drawable.cpp for display list management. So I guess if our choice of using VBO is still valid or do you think we can switch to display lists?


On the other side did someone experience this kind of problem with Qt 5.11 (or a version greater than 5.5)? Maybe there is a solution changing some Qt settings.

Thank you in advance.

Best regards
Ale

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http://forum.openscenegraph.org/viewtopic.php?p=73896#73896