Technical question about picture opacity

[uuderzo]

Hello... little question about opacity and performance.

I wish to perform a huge zoom effect in a O&A sequence.

I have 4 pictures of the same subject taken at different zoom levels.

I wish to put the image 1 in "fill screen" mode, and to insert as children images

the other pictures, scaling and positioning them so they appear merged in the

root image (maybe fading them on the borders with alpha channel to obtain a better merge)

I hope this way to obtain, zooming at the smaller (but in high resolution) image

a huge zoom effect that keeps always in high res the focused area of the image.

My question is about the outer images. Zooming a lot on the smaller image leads

the graphic engine to draw a really big outer image. If I put to zero the opacity of

a picture when I know it is completely covered by the subsequent inner picture,

can I obtain a performance gain?

Thanks... Umberto

[thedom]

If I put to zero the opacity of a picture when I know it is completely covered by the subsequent inner picture,

can I obtain a performance gain?

Hello Umberto,

I don't think putting to zero the opacity of an object will affect the performance because the object is still "displayed" even if you don't see it.

What you could do is to split the zoom in three slides instead of a single one :

- The first slide will include image #1 and #2. You will zoom image #1 until image #2 is displayed full screen.

As you said, image #2 will be children of image #1.

- The second slide will include image #2 and #3. You will zoom image #2 (starting from full screen) until image #3 is displayed full screen.

Image #3 will be children of image #2.

- The third slide will include image #3 and #4. You will zoom image #3 (starting from full screen) and then #4.

Image #4 will be children of image #3.

If you took your images with a tripod and with the same amount of zoom between each of them, the result should be fine, otherwise, the zoom will not be linear.

Hope it helps.

[uuderzo]

Yes, I can try this way.

I would prefer the "single slide" solution only because it's easier to manage a single entity with zooming and panning.

I'll try your solution in case of performance troubles.

Thank you! Umberto.

Hello Umberto,

I don't think putting to zero the opacity of an object will affect the performance because the object is still "displayed" even if you don't see it.

(...)

[Igor]

Objects with zero opacity will not be displayed at all and they don't take power of video card.

But please remember that such image object still remains in video memory. If slide too heavy (many large images) it may work slowly because of lack of video memory.

[uuderzo]

This sounds reasonable.

Thank you for the clarification Igor!

Objects with zero opacity will not be displayed at all and they don't take power of video card.

But please remember that such image object still remains in video memory. If slide too heavy (many large images) it may work slowly because of lack of video memory.

[Lin Evans]

Hi Umberto,

If I understand you correctly, what you want to achieve is a continuous zoom effect from perhaps a wide angle to extreme closeup or "macro".

Quite a while ago we experimented with this "endless" zoom concept and found that the easiest way to achieve this was by placing the images on separate slides then precisely matching the ending of frame one with the beginning of frame two, the ending of frame two with the beginning of frame three. There were several discussions on the forum about the best way to achieve this and some good suggestions were offered by several forum members.

I found that the easiest way for me to do this was to temporarily place frame two as an object on slide one - set the opacity of slide one AND object 2 to about 50% - overlay the images perfectly visually (use the grid if necessary) then copy and paste the pan, zoom and rotate figures for object 2 to slide 2 then delete object 2 from slide 1. Repeat for each successive slide.

I made a couple demo shows which I will link to below. Because I didn't perfectly sequence the original photos with small enough increments in focal length you will see some obvious breaks in the zoom smoothness, but it's close enough to get the idea. On the original slides never exceed 100% zoom (don't zoom beyond 1:1 on any single slide). Match lighting, hue, saturation, levels, etc., in Photoshop for each slide. This can be done to achieve an "endless zoom" effect.

http://www.learntomakeslideshows.net/demos/kachinazoom.zip (about 23 meg zipped exe)

Also read this thread and look and Andrew's sample:

http://www.picturestoexe.com/forums/index....20zoom&st=0

This may help you with some ideas....

Best regards,

Lin

[uuderzo]

Yes Lin, some sort of.

My need is to zoom a mountain landscape up to a single hill where the cave entrance is situated.

I have 3 shots and will try the technique you suggested, placing my pictures on single slides.

Hope to get a good result since working with landscapes the depth of field problem should be minimized.

Bye! Umberto

Hi Umberto,

If I understand you correctly, what you want to achieve is a continuous zoom effect from perhaps a wide angle to extreme closeup or "macro".