查看: 2481|回复: 9

[Anark] Frame Rate Watcher (Miscellaneous Behavior)

Asen

867 主题	0 听众	1万积分

外协人员

Rank: 7 Rank: 7 Rank: 7

纳金币: 17488
精华: 1

电梯直达

楼主

发表于 2011-10-21 08:19:00 |只看该作者 |倒序浏览

            Frame Rate Watcher (Miscellaneous Behavior)


         Summary


         Fires events as the frame rate of the presentation enters one of three ranges.


            Category


            Latest Behaviors


            Author


            Gavin Kistner


            Difficulty


            (Reference)


            Time to Complete


            5 Minutes


         Downloads


         Click Here

         to download the associated files.


         (This document covers version 1.0.4 of the 'Frame Rate Watcher' behavior, current as of 2005-Feb-11)


         Description


         This behavior calculates the frame rate of the presentation, and fires one of three events as the frame rate enters certain ranges:


            Terrible Fps


            —This event fires when the frame rate drops below the value of the

            Low FPS

            property.





            Acceptable FPS


            —This event fires when the frame rate is between the

            Low FPS

            and

            High FPS

            values.





            Awesome FPS


            —This event fires when the frame rate exceeds the

            High FPS

            value.


         These events may be used to cause a presentation to automatically adjust itself to the user’s machine speed, switching to lower-resolution models and image maps if the frame rate is too low, or perhaps hiding certain items.


         The frame rate to use for the tests can be calculated in one of three ways, specified by the

            FPS Method

         advanced property:


            Running Average


            —(default)The frame rate is calculated as a running average over a certain number of frames, specified by the

            Running Avg Size

            property.





            Quick Average


            —The frame rate is calculated as halfway between the previous average and the last frame’s rate. Responds quickly to sharp changes in frame rate, but takes a long time to reflect any stable

            FPS

            ‘plateau’.





            Overall Average


            —The average frame rate for the entire duration of the presentation.





            Last Frame Only


            —The frame rate reflected by how long the last frame took to compute. (This rate is ‘fickle’ and may have dramatic spikes.)


         The

            Crossover Threshold

         advanced property is used to prevent slight fluctuations in frame rate across the border between two ranges from firing the two events. With an acceptable

            Low FPS

         value of 10 and a

            Crossover Threshold

         value of 2, the frame rate will enter the “

            Terrible FPS

         ” range if the frame rate drops below 10fps, but will not return to the “

            Acceptable FPS

         ” range until the frame rate rises above 12fps. The same is true for border between “

            Acceptable FPS

         ” and “

            Awesome FPS

         ”.


         Finally, in addition to firing events based on the specified frame rate calculation, placing this behavior anywhere in the scene will create and maintain four new properties on the

            player

         object:


            player.runningFPS


            —The

            Running Average

            frame rate.


            player.quickFPS


            —The

            Quick Average

            frame rate. (aka

            player.avgFrameRate

            )


            player.overallFPS


            —The

            Overall Average

            frame rate.


            player.lastFPS


            —The

            Last Frame Only

            frame rate. (aka

            player.frameRate

            )


         This behavior will function the same whether you attach it to the Scene or to any other object; the only reason to attach it to other objects would be for convenient relative referencing by an object which uses this behavior.


         Basic Properties


            Low FPS


            Minimum Frame Rate for the 'Acceptable FPS' range.


            High FPS


            Minimum Frame Rate for the 'Awesome FPS' range.


         Advanced Properties


            FPS Method


            Which FPS calculation should be used to fire the events?


            Running Avg Size


            How many frames should be averaged for the Running Average FPS?


            Crossover Threshold


            Size (in FPS) of the boundary between ranges.


         Events


            Terrible FPS


            Fires if the frame rate drops below the 'Low FPS' value.


            Acceptable FPS


            Fires once when the frame rate moves between the Low and High values.


            Awesome FPS


            Fires if the frame rate is above the 'High FPS' value.


         Demonstration


            View Demonstration Project


            Download Project File