How is Scale calculated?

I’m trying to understand how scale works in Synfig. I have two images both sized 500x500px. I have resized my canvas to 500x500px and have set images to be scaled to the canvas size. However, when I import the images the Scale of these is 77.0371x77.0371px.

How is this being calculated? In programs such as Natron and Blender’s compositor the scale parameter is in relation to the original size of the imported image, so scale 1 is unchanged, scale 2 is double size (1000x1000), 0.5 half size (250x250) etc.

I’ve attached my project and files. I’m using Synfig (55.7 KB)

Check the options of the Canvas (F8) on first and last tab.
Some parameters are checked by default, changed according Synfig’s version and thus not behaving the same…


Exactly which parameters are you referring to?

I’ve read that thread but can’t see how it relates to what I described.

The image is being displayed at the right size on the 500x500 canvas but in the parameters editor it’s displaying the scale of the image at 77.0371x77.0371px


Oh my dude, you just got pranked :slight_smile:

The 77.03 number is in fact scale 1.0 as you would expect. Synfig just trolling you because it handles different measurement systems poorly. It’s native format is “units” but in your case it is set to pixels so everything gets converted to them. And with resolution 500x500 the 1 unit is ~77.04 px. Unit is relative to resolution, so for example for 480x270 it’s 60px and for 1920x1080 it’s 240px.

Just work with “units” until Synfig gets better with different measurement systems. You can change it in “Edit->Preferences->System->Unit System”.

This should be fixed… Scale is just a relative number (like %), it shouldn’t be shown as a “distance”.

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Thanks for explaining but it seems really odd that the scale of a layer/object can change if the canvas changes size. As @rodolforg says it should be fixed/changed.

If there’s not a bug report about it already I’ll make one.

Wait, why is it odd? Seems pretty logical to me. I do want to upscale everything when I change canvas size because I work with vector forms and it scales up perfectly.

If you want to change the size of the canvas without upscaling everything, then do the following:

  1. Go to “Canvas->Properties->Other”. Make sure that only “Pixel Aspect” is checked. Click “Apply”.
  2. Go to “Image” tab and specify the new resolution, click “OK”.

What I and @rodolforg meant is that parameters that specify scales, amounts, you know, anything relative, must not be converted in pixels/centimeters/whatever but always remain in units (floating numbers like 1.0, 2.0, 0.5, etc.).

Also, have a look here: