Alpha masking / moving or resizing a mask

stefanino

Hi,

I'm working on a patch that reveal a picture, the idea is to have a picture revealed under a black layer, moving the mouse the user can see a portion of the image...

I've started combining an alpha mask actor with a foreground black layer, a background with the choosen image and a mask that is a PNG file, a little circle on transparent. Unfortunately, this doesn't work, it gives me unexpected results and I'm not able to move the mask "revealing" the image layer: if I de-zoom or move the image mask, the results it that moves also the wireframe around the mask! So the image is already revealed and the result is very bad! I am quite sure that is possible to have my goal done, and the only issue is that... I can't find the solution! someone out of there can help me?

thanks

Stefanino

stefanino

Thanks for any ideas or suggestions

CitizenJoe

Try the Shapes actor!

Cheers,

Hugh

MatthewH

Ill second Hugh's suggestion. The shapes actor plus the alpha mask actor is going to do what you need.

stefanino

Yes, I've tryed now and it works. Thanks

Skulpture

And use a bit of gaussian blur to give it a smooth edge (if needed).

stefanino

Yeah Graham, of course I've used also Gaussian Blur... it looks fine!

Going on next level: I'd like to use the mask like an "eraser" that reveal the photo, until is completely visible.

I am experimenting with and the mask moves motion blur is giving me the best results, but still isn't what I would to do, mainly because the current position of the "viewing hole" is burned and, of course, because because motion blur "viewing tray" is temporary... (I've also tried with Video Delay and Sprite actors put on a second projector, but it seems more bad...). Any suggestions?

as usual, thanks to any ideas...

S

Skulpture

You might be best looking at something like the buffer actor and freeze?

I made something a while ago but it's not on the machine I am using at the moment. I used it for erasing part of a mask for video mapping.

MatthewH

Freeze in a loop of sorts with a pulse generator is one good possibility. Some clever use of the Particle system actor is also a viable approach.

Michel

@stefanino

Attached is a patch that does what you want.

Best
Michel
286b05-erasereveal.izz

bruper

that is nice @Michel , maybe with the gaussian blur between shapes and effect mixer, I was trying to get the final video with a black BKG but cannot find the way to make it work... suggestions please?

Michel

@bruper

if you want the same starting with black instead of white, see the attached patch.

Best
Michel
7416f9-erase_revealblack.izz

bruper

@Michel

thanks, that works fine, I added a Table to change mode on the Effect Mixer in order to go to black together with the intensity in the projector so to make it a loop

best regards
Bruno

stefanino

Hi everyone,

sorry I am away from computer for some days... I'll try next week

For now, thanks in advance!

S

Kathmandale

Hello,

this is from a patch I was working on a few weeks ago; it's fairly similar to the one posted by Michel above. We were trying to recreate the effect of a long exposure picture taken with a stills camera but the principle is similar. Swap out the 'Video In Watcher' for a combo of the 'Stage Mouse Watcher' & 'Shapes' as in Michel's patch. It will give slightly different results to the motion blur patch, try playing with the frequency of the pulse generator to get different effects.

Best,

Crofty

fc9c1b-painting-with-light.izz