View Full Version : Possible bug in LWFilterAccess shutter params

09-13-2007, 12:39 AM
LightWave passes a LWFilterAccess struct to the process() function of image filter plugins. The "start" and "end" fields of this struct are supposed to contain the shutter open and close times. With previous versions of LightWave, "start" and "end" were always the same when motion blur was off, and different when motion blur was on, as they should be. This is still the case for LightWave 9.3 in "Classic" camera mode. However, when using one of the new camera modes like "Perspective", if the classic AA mode is set to 1 pass, the "start" and "end" values passed to my plugin are the same, yet the final render does show motion blur on scene objects. I believe this is a bug. "start" and "end" should always reflect the shutter open and close times used for motion blur purposes.

09-13-2007, 01:18 AM
Sounds like a well hidden bug, good hunting!

Do 'start' and 'end' work if you use more than one motion blur pass?

Post this to lw-bugs(at)newtek(dot)com

09-13-2007, 02:04 AM
Do 'start' and 'end' work if you use more than one motion blur pass?
No, even with 2 or more motion blur passes, "start" still equals "end". It looks like "start" and "end" are determined solely by the Classic camera parameters, even when a non-Classic camera is used for rendering.

09-13-2007, 09:50 PM
It is indeed quite probable that the setting of those values wasn't updated to include the effects of the new motion blur.

As a work-around, you could use LWCameraInfo->frameTiming() to get the exact ranges of time that are sampled for a given frame.