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MrKepzie / Natron

Open-source compositing software. Node-graph based. Similar in functionalities to Adobe After Effects and Nuke by The Foundry.
www.natron.fr
GNU General Public License v2.0
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Blur node wrong "Expand RoD" result #1732

Closed fabiof17 closed 6 years ago

fabiof17 commented 6 years ago

Problem

The Expand RoD of the Blur node still crops pixel at the very borders. It's something i had noticed for quite a long time.

Expected behavior: Display all the blurred pixels

Actual behavior: Pixel on the edges are cropped.

Steps to Reproduce

  1. Draw a roto
  2. Add a Blur node

Screenshot :

bug

Versions

devernay commented 6 years ago

That's normal behaviour. The Gaussian filter is actually an IIR (infinite impulse response) filter, so the blurred pixels actually occupy an infinite area. We had to cur somewhere, and that somewhere is at 99.5% or something like that. We use the same cutoff as Nuke btw

fabiof17 commented 6 years ago

You're absolutly right. For some reasons it wasn't that obvious in Nuke. Anyway... I just noticed that as i am currently struggling with RoDs in Natron. I'm always expecting Natron to behave exactly like Nuke, which is obviously not the case. But that's another discussion.