Can effects enlarge the canvas?

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Sadler
Posts: 240
Joined: Tue Sep 20, 2011 23:55

Can effects enlarge the canvas?

Post by Sadler »

With many effects the effect goes outside of the canvas which, if the canvas is the same size as the screen and the effect isn't rotated or shifted it isn't a problem. If however the source clip is smaller than the output, or the clip is rotated for example, the effect is cropped (and often shrunk) to the original dimensions of the source clip. This is also the case when a clip is scaled down to less than the dimensions of the output. Sometimes moving the transform section to before the effects is a work-around for some situations but not universally.

This is most egregious with Bendoscope, Blow, Circles, Fragment, Iterate, Kaleidoscope, Mirror, Mirror Quad, Particles, Pixels in Space, Point Grid, Radial Blur, Slide, Snow, Stingy Sphere, Terrain, Tile, Tryptafx Kaleido, Tunnel and fugFeedback.

One work-around is to make sure all your clips match or are bigger than your intended output giving padding to a 200x200 "sprite" for example to make it fill FHD. However, this doesn't help if, for visual balance reasons you want to scale the clip in the comp.

Another option that could be added to Resolume itself would be to autopad clips to the output dimensions so that any frame sent to an effect would have the whole canvas no matter the original dimensions or the scaling. Alternatively, the user could select how much padding centered in x and y they want. e.g. I want my 200x350 clip padded to 1280x1280 before I apply my effect.

The reason I put this query into the developers section is because I wanted to ask if there was an inherent limitation with FFGL that meant they couldn't expand the canvas automatically so that the effect would have influence at least up to the output dimensions.

Joris
Posts: 5186
Joined: Fri May 22, 2009 11:38

Re: Can effects enlarge the canvas?

Post by Joris »

Interesting. Placing the transform before the effect should process the clip at the comp size. In fact, what you describe is pretty much exactly what it's meant for.

Could you share an example of where that is not the case?

Sadler
Posts: 240
Joined: Tue Sep 20, 2011 23:55

Re: Can effects enlarge the canvas?

Post by Sadler »

Yes, interesting maybe but pure porkies. Sorry Joris, everyone. I've been doing tests and trying to justify my diatribe to no avail and managed to find a workaround for all my frustrations. I must have been too tired or let my inner noob out momentarily.

That said, there is still, debatably, room for making this aspect slightly better. Adding an image or clip intentionally not at output aspect ratio (commonly square) can be fiddly unless one gives oneself a lot of legroom.

Here's a comparison of various effects before and after the transform using a largish (1920x1920) square bitmap as source. One can't do this with smaller bitmaps since the effects adopt the dimensions of the source and putting the transform before the effects requires adjusting the dimensions and scaling differently for different effects.

Joris
Posts: 5186
Joined: Fri May 22, 2009 11:38

Re: Can effects enlarge the canvas?

Post by Joris »

Nice content for those effects!

Changes in aspect like this are nature of the beast with these plugins. On some plugins ( PolkaDot and Triangulate for instance ) we can check for aspect ratio. For others ( like Tunnel ) the input texture has to be square in order to get proper circular shapes.

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