Papervision 3D Framerate

Let us share some constructive hands-on tips or trix on how to increase framerates. There's a lot of design issues from modeling 3D-objects to bind them to value-/business objects (classes). However, you should also take the rendering principals of the Flashplayer and your 3D-API in consideration! The gems in this topics may be, in no particular order, under clever headlines, so feel free to contribute by comments.

1) Override Flex default framerate of 24 by setting the desired framerate Application property in *.mxml (haven't got it to work from CSS). Try framerate 60, and hope that the Flashplayer may reach the fps of 40 once in a while.

2) Ask your self when and why you need to run onEnterFrame()! Even for a design built with constant movement in mind, it is a good strategy to provide for situations where a 3D world is allowed to freeze for a couple of seconds. If you can make it freeze without the user notice it - good for you. You will need that time to load additional assets or resources.

IMPORTANT!!! Try NOT to use onEnterFrame() at all in your 3D viewport rendering engine! Try the Timer intervall instead. And above all - try NOT to use two or more onEnterFrame()-callbacks in parallell, that will probably sink you application framerate below 10 fps.

In PV3D all DisplayObject3D have a pointer to the scene or context they belong to. Therefor you may choose to use the Scene object as the eventdispatcher for such events as PLAY and STOP to control when to stop or run the onEnterFrame.

3) If you know, or if the 3D object or face itself know that it should be invisible - set its visibility to false. In that way the the culling process does not even need to calculate.

4) Z-depth and culling calculus are process intensive. One finding I had was with a cube, or rather six individual planes, with no awareness of eachother, in a group forming a cubelike shape. I wanted to keep the cube in constant movement of a Perlin noiced sine function in each degree of freedom (DOF). The cube was rotated with in a slow wobbeling motion showing the same three faces to the camera, two sides and the rooftop. I found that the framerate decreased when one face - the rooftop - had it's normal almost perpendicular to the camera. The more the rooftop pointed it's normal direction towards the camera the framerate increased.

Thus, a large surface with a tiny projection to the view plane is more computationally heavy than when the same side projects more of its surface to the view plane! By rotating the default angle of my cube slightly, the culling did not kick in, and I increased the framerate by two times.

5) Over all for FlashPlayer rendering, check how Bitmap Cache Policy can be used in your project..