Due to performance issues, I’d like to unload models and load new ones. This is when you enter a building “in game mode”, then I’d like to remove all the scene and load new one. Is there a way to do that?
Also, I displayed FPS on the screen, but is there a way to display number of polys or verts rendered?
Apologies if my question seems too basic. I’m not yet proficient with Panda.
My problem is that I load many models (.egg files) into 3D scene. I can unload them using myModel.removeNode(), but I wanted to check with the community what’s the best approach and common practice here.
My idea was to create a separate file, say called load_game_models.py and use import to run it. Then I could create unload_game_models.py and import it when needed. Yet maybe there is a way to unload all the models with a single command?
Also, does Panda render the polygons, which are not visible?
Let me explain why I ask this question. I created a building model and I program it, so you could “enter” the building. I can either add the interior building model to the whole scene or I can unload all the models and load it separately. The latter would work well if Panda renders all the polys no matter what.
I tested my code on low performance and high performance computers to see how it works. On low comps it makes a difference. If I “swamp” the scene with something over 50,000 polys the output starts to be choppy.
Any advise/comments on the above mentioned topic would be really helpful.
removeNode() should be enough. You could also use loader.unloadModel() to remove the model from cash (or memory?) but I don’t think that’s really a necessity.
The question about rendering visible polygons is a bit complex.
There’s view frustum culling in panda. Object that are totally out of the cameras view are not rendered, but there’s no occlusion culling - things that are invisible to the camera because they are behind some other objects will still be rendered (send to the gpu).
So if you have a interior and a exterior then both will be send to the graphic card if the camera is facing them even if the interior is hidden behind a wall.
You could hide the interior behind an OccluderNode, but I can’t give you more then the manual page about that:
panda3d.org/manual/index.php … er_Culling
Hiding and showing the interior and/or exterior seems a good option for me. You don’t have to remove them totally, just use NodePath.hide()
You can use pstat for some benchmarking and performance tuning, there’s a good page in the manual about that:
panda3d.org/manual/index.php … ith_PStats
Many thanks. This will keep me busy with studying the Manual.
Yes, I mostly refered to occlusion culling - things that are behind some other objects. Hiding the Interiors sounds like a good solution.
I was also thinking to hide parts of the map based on the location. In other words if you enter a certain segment of the map (based on X, Y coords) the proper package of models will unhide. Something like this. This would eliminate small objects, which are far away or behind other objects.
Is there a quick way to see how many polys are rendered by Panda (or verts)? Same as you can see FPS in the upper-right corner. This would be enough at least for a start, till I make a full use of PStats.
Yes, but that quick way is PStats. 
David
OK thanks. 
Off to study this section of the Manual.
I’m marking the topic as ‘Solved’. Again many thanks for your help and advise. I really appreciate that.