How to get the layer size including outer shadows?

[Chris13123]

I have a circle with an outer shadow. But the Transform panel is only showing the circle dimensions and not the total dimensions including the outer shadow. Is there any way to get the full dimension?

 

Thanks!

[joe_l]

8 minutes ago, Chris13123 said:

Is there any way to get the full dimension?

With the help of math? Circle dimension + shadow radius = full dimension. IMO the only way. Temporary rasterising the object gives the false dimension.

[carl123]

6 minutes ago, joe_l said:

With the help of math? Circle dimension + shadow radius = full dimension.

Won't that result be affected by the Shadow Offset setting?

7 minutes ago, joe_l said:

Temporary rasterising the object gives the false dimension

How is it false?

[thomaso]

5 minutes ago, joe_l said:

Circle dimension + shadow radius = full dimension.

Not really. It seems to be rather Ø + 2r

Here the red square is 650 px (and the shadow visibly slightly exceeds this size) …

… while an export of the Circle only (export as selection) results in an image of 751 x 751 px:

… which indeed gets exported as auto-set by the app:

[Chris13123]

Temporary rasterizing seems like a good enough way, is the dimension correct afterwards?

[thomaso]

5 minutes ago, carl123 said:

Won't that result be affected by the Shadow Offset setting?

If offset to one direction it increases in this but decreases in the other direction.

[thomaso]

9 minutes ago, Chris13123 said:

Temporary rasterizing seems like a good enough way, is the dimension correct afterwards?

It does not to seem so: compare the results in my post above (751 px) with this rasterized layer below (716 px).
So it seems the auto-calculated export size ('selection area') is more reliable than the rasterized version.

[NotMyFault]

40 minutes ago, Chris13123 said:

I have a circle with an outer shadow. But the Transform panel is only showing the circle dimensions and not the total dimensions including the outer shadow. Is there any way to get the full dimension?

 

Thanks!

I would first ask how you define the „full dimension“, as a shadow normally introduces a blur and partial transparent pixels. Where do you want to take the demarcation? For what purpose do you need the dimensions? Exporting, copy / paste, aligning with other objects, measuring, …?

[NotMyFault]

21 minutes ago, thomaso said:

It does not to seem so: compare the results in my post above (751 px) with this rasterized layer below (716 px).
So it seems the calculated export size is more reliable than the rasterized version.

Good findings.

i personally never trust „export size“, there are too many examples where export size is far larger than required, adding transparent edges.

If you need the „export size“ (including transparent edge pixels) as answer to the OP question, it is the best answer,

If you need the size of non-transparent pixels, use the size of the rasterized layer.

Below you see the export to PNG (selected area, e.g. Circe with shadow).

If you open the file and use a levels adjustment to boost alpha channel (all non-zero alpha becomes 1, zero stays zero) you see an area of transparency. Another recheck is to use rasterize again after opening in photo, the resulting layer will show the smaller size.

[NotMyFault]

Drum roll

i think i solved an old mystery.

my above post was using RGB/8 document.

i Repeated the same procedure with RGB/16: Now there are no unneeded transparent pixels.

This means that unnecessary transparent pixels at export are caused by Affinity is using RGB/16 accuracy to calculate sizes (even in case of RGB/8 document), but the actual export is done in RGB/8 accuracy. Those areas who are truncated to zero in alpha channel cause the unwanted transparent edge pixels.

 

 

[thomaso]

Your examples make it more clear, especially the RGB/16. But I still don't understand this conclusion …

32 minutes ago, NotMyFault said:

If you need the size of non-transparent pixels, use the size of the rasterized layer.

… because In my mind every pixel in a soft shadow has transparency. (~ the 100% black area is extremely small, right?)

In my test I tried to increase the Shadow Intensity first to get all shadow displayed opaque – but unfortunately this increased the shadow dimensions quite obviously. (my test was done in CMYK, export as RGB/8).

[Chris13123]

Yeah I can confirm that exporting the selection is way bigger (1100x1100) than the rasterizing method (1020x1020) while the layer without shadow has a size of 940x940. As long as the rasterizing method doesn't cut off any shadow, I will be going with this solution!

Thanks guys!

[v_kyr]

Since the OP tagged ADe, what does the ADe Measure tool tell, meaning here does it just measure the main circle object, or can it also take the applied shadow together into account?

[NotMyFault]

5 minutes ago, Chris13123 said:

Yeah I can confirm that exporting the selection is way bigger (1100x1100) than the rasterizing method (1020x1020) while the layer without shadow has a size of 940x940. As long as the rasterizing method doesn't cut off any shadow, I will be going with this solution!

Thanks guys!

it does, depending on color format of the document.

If you use RGB/16, the shadow will be larger that in RGB/8. But it will be cut-off anyway, so no difference.

 

[Chris13123]

I just tested this.

Rasterizing:

RGB/16: 1030x1030

RGB/8: 1020x1020

CMKY: 1020x1020

Exporting:

RGB/16: 1100x1100

RGB/8: 1100x1100

CMKY: 1100x1100

But Exporting gives me too much padding which I don't need.