Sprite disappears inside Replicate In Space Patch

Lango's picture

Hi

I hope some one can help me with a problem with the Replicate In Space patch.

I have attached a strip down version of my project called Replicate in Space Bug.

In short, if I use an interpolation patch inside a replicate in space patch, sometimes the elements that is being replicated disappears.

To reproduce you can follow these steps.

  1. To see the whole layout change the "Translation Z" Input Parameter to -40. Here you can see the orange box + yellow rectangle that is being duplicated 3 times.

  2. To see the orange box disappear change "Translation Z" from -13.7 to -13.5 (Note: This is the same time the orange box on the right goes off the screen)

  3. To see the Yellow rectangle disappear change "Translation Z" from -10.5 to -10 (Note: This is the same time the yellow rectangle on the right goes off the screen)

  4. Drill down to Root Macro Patch -> Replicate in Space -> 3D Transformation -> 3D Transformation, and disconnect the Interpolation from the orange square's Y Position. Now repeat 2 & 3. You will notice that they no longer disappear and the Replicate in Space patch is working as expected.

I have no idea why this is happening or why the interpolation patch is causing an issue, but a very similar bug is causing me issues in my main project. I would be very grateful if anyone could shed any light.

Cheers

Lango

PreviewAttachmentSize
Replicate in Space Bug.qtz7.64 KB

cybero's picture
Re: Sprite disappears inside Replicate In Space Patch

I'm not sure if this is a bug, or just a result of the way that QC works out co-ordinates and positions on objects.

Seems to me that it's mainly to do with the X origin, the X Final Translation, before you get onto the Z axis Translation.

Swapping negatives for positives and visa versa will get you a similar result as items disappear to the left as the Translation Z axis goes down.

cwright's picture
Re: Sprite disappears inside Replicate In Space Patch

unrelated, but I find that if I put a sprite in a replicate in space (2 copies), and put the replicate in space in a trackball, the viewer will periodically freeze for several seconds at a time (or until I click out of QC and then back in) - after a few seconds I get a beachball. Does anyone else experience this? (8800M GT)

cybero's picture
Re: Sprite disappears inside Replicate In Space Patch

No.

In fact quite the reverse - no problem at all, other than the trackball just spinning for ever under nil friction conditions •~ :-) .

BTW, is the Sprite[s] disappearing from the Translation defined viewport count as a bug, or is it just doing what QC units "expects" ?

Trackball still spinning - no beachball - after one [make that fifteen] minute[s].

Oh, and running a 9400 nVidia iMac, which is reckoned to share the same OpenGL version specifications and facilities as the 8800M GT.

cwright's picture
Re: Sprite disappears inside Replicate In Space Patch

interesting -- thanks for testing, cybero.

(I continue to wonder if my 8800 is one from the flawed batch -- when playing video full-screen, it'll occasionally just stop updating the display (but continue to play audio), beachballing the mouse until you switch apps (or I ssh in and kill the media player)).

I'm unable to do more testing at the moment, but I'm guessing the sprites disappearing is a bug due to QC's obsession with minimizing work (at the cost of correct behavior). I'll try to check it out.

Lango's picture
Re: Sprite disappears inside Replicate In Space Patch

If it disappeared wether the interpolation patch was there or not, then i could understand it not being a bug, but to me having it behave differently I would consider it a bug.

Would you happen to know anyway of stopping it from disappearing or if I am doing anything wrong?

In my project I use the Replicate in Space Bug to create a panorama effect, and having some objects disappear when it goes back to the start is quite annoying. Perhaps there is another way to make a panorama?