Digital Workshop

Hi,

(I hope this is not another stupid question...)

I'm trying to crop an image horizontally to simulate an old-fashioned LED VU meter. Each 0.10 seconds or so the Image width must change randomly to give a realistic effect. However this seemingly simple task has proved quite tricky, for I had to insert the VU Image inside a frame, change the Image size using SetObjectSize() (SetScale() doesn't work for this), then call SetPosition() to compensate for the fact that the scale is based on Image insertion point, i.e. the center, not the left. I had to experiment a lot to overcome the jitter caused by dividing odd widths by 2. It gets better if I offset the image quite a bit, but after half a minute or so the jitter starts again (I suppose SetObjectSize() deforms the Image after a while).

Please look at the attachment to see what I mean.

Isn't there a simpler way to do this?

Thanks in advance for any help.

Hi Ruben,

I'm no expert with OpusScript but I tried using a different method. I appended to your IMP file... look at Page 2 for details. It does not answer your question though, as you'll need someone better at scripting and it may be to do with the way SetObjectSize() works

If the meter keeps working all the time showing random levels, then I'd probably go a simpler route and produce the whole meter as an animated GIF ...if you use enough different frames in the animation it should look pretty convincing. We made an LED meter for a website this way some years back.

Rob
www.visibleform.co.uk

Thanks Steve, your method is certainly simpler and gives a better animation -- although it has the drawback of not showing the small black rectangles (i.e. the LEDs turned off). I'll stay with it for now.

This would certainly do it, but seems a lot of work to me. I believe Opus Pro, being a complete multimedia /rich media package, should have a simple way of masking and cropping bitmaps!

Maybe - but, unless you're rendering out to video, you're asking Opus to do all this work in real time at runtime - which will possibly reduce it's capability to show/do other stuff smoothly at the same time ...I usually try to reduce the runtime calculation burden of any multimedia software as much as possible to improve overall performance. You can import huge images into Opus and ask it to crop/resize them at runtime, but most folks will advise you import at the size you intend using ...for the same reason.

If you're producing an LED meter, it's pretty easy to do this with something like Animation Shop (used to come with Paint Shop Pro) ...produce the basic meter in Paint Shop Pro, or Photoshop, and then export multiple versions of it with different LEDS lit up - import into Animation Shop to make the final GIF file and adjust the timing between the various frames to suit.

Rob
www.visibleform.co.uk

Hi Rubem,

I was going to suggest using an animated GIF too. (as Rob has pointed out)



You could try using a marked vector line in the draw tools, instead of the solid frame blocks I used. Or if you want it exact, you could easily crop the section of the LED meter with two small images and use them.

Hope this helps.

I may be missing something here but surely the simplest approach is to place the bar inside a smaller frame and move the bar up and down, so using the container frame to "clip" the display?

The easiest solution is to create two Slideshows (Left & Right meters), each with 4 or 5 different VU meter "readings", then set the time for each slide to be less than 1 second, and have them appear in Random order Continuously.

Here is my final (if such thing exists) solution. It's pretty straighforward, uses only one bitmap for the VUs and maybe it's useful for someone. Thanks for you all for helping me think simple