Layer Blend Option Preset?

[LightCreator]

Is there a way to have a preset for a layer blend option curve?

I have greyscale image plans exported from a drafting program, and would like to bulk edit files to make the white in the drawing transparent for placing in presentations. 

I found a way to do this here: Affinity Forum: Make white transparent, and it seems to work in my drawing. 

Attaching drawing, pre and post edit, and a snip of the layer blend curve I am trying to set. 

[walt.farrell]

There doesn't seem to be a way to create a Preset, per se. However, there some alternatives that might work for you.

For example, you could create a Group, and apply the Blend Ranges to the Group. After that, you can put your drawing inside the Group, and the Blend Ranges will apply. You might even create an Asset from the Group to save it for later reuse. (Note: if you leave the Group empty, it will be hard to see as an Asset, so you might want to put something in it, which you can later delete when you drag the Asset to your project.

Or, you could create a Layer (in Designer or Publisher) and apply the Blend Range to that Layer, and proceed as above.

[thomaso]

And, in addition to Walt's hints, here a workaround in case the image layers don't have any style assigned:

You can copy a selected object which has the desired blend range set, then select one or more other objects to apply this setting via menu "Paste Style". – Accordingly you can create a style in the Styles Panel with the wanted blend range curve and use this to assign it to future objects.

[LightCreator]

Thanks Walt! 
 

I may go the asset route, since I think I may be able to automate this. 
 

When needing to do this I typically have 5 or more files I need to batch convert, so this seems like a promising route!

[carl123]

1 hour ago, LightCreator said:

Is there a way to have a preset for a layer blend option curve?

I have greyscale image plans exported from a drafting program, and would like to bulk edit files to make the white in the drawing transparent for placing in presentations. 

In APhoto you can record a macro to set your required Blend Ranges

Then replay that macro in the Batch processing dialog of APhoto to appy it to all required images

[walt.farrell]

29 minutes ago, thomaso said:

You can copy a selected object which has the desired blend range set, then select one or more other objects to apply this setting via menu "Paste Style". – Accordingly you can create a style in the Styles Panel with the wanted blend range curve and use this to assign it to future objects.

That gets tricky, though, as a Style encompasses many aspects of an object, including its Fill (or lack thereof), Stroke (or lack), etc. and so when you apply the Style you may well change other aspects besides the Blend Ranges.

[thomaso]

1 minute ago, walt.farrell said:

That gets tricky, though, as a Style encompasses many aspects of an object,

That is why I mentioned "in case the image layers don't have any style assigned" before I mentioned the method.

However, the description to this topic seems to talk about technical drawings without the purpose to style them with colour, while, even if, it seems they all would get styled the same – and, even if not: When the blend mode gets assigned as Style at first, then any further styling doesn't harm.

[walt.farrell]

1 minute ago, thomaso said:

That is why I mentioned "in case the image layers don't have any style assigned" before I mentioned the method.

Yes, but many things count as "style" including Stroke and Fill. Many objects have a Stroke or a Fill, but do not specifically have a Style assigned to them. And the OP's drawings, for example, are likely to use both Stroke and (in some areas) Fill. Thus, using Styles for this can be tricky.

[thomaso]

4 minutes ago, walt.farrell said:

Many objects have a Stroke or a Fill, but do not specifically have a Style assigned to them. And the OP's drawings, for example, are likely to use both Stroke and (in some areas) Fill.

I can't follow. The OP's resources are described as "greyscale image plans exported from a drafting program", which sounds to be pixel rather than vector. Accordingly, these images initially neither have nor need any fill or stroke being assigned in Affinity.

[LightCreator]

This is correct, for this instance I am using raster images from the background, then exporting as PNG with transparent background. 
 

I could export DWG from my program (Revit) and import to Designer, however the dwg import puts each line as an individual object, which is not complexity I need for this use case since I don’t want to modify stroke weight or color. 
 

That said, always looking for better ways to improve my workflows and if I end up needing to change the strokes, using Designer seems to be the way to go. Especially since I’m V2 you can sort by later which makes dealing with individual objects less cumbersome. 

[thomaso]

Alternatively you might try PDF export from Revit if available. This can keep the file contents as vector with the options …

a. to place it in Affinity as resource,
b. rasterize the contents within Affinity in any image resolution,
c. or open the PDF in Affinity and edit its curves.

Depending on your needs and the export options from Revit it can be worth a try.

[LightCreator]

I think I would prefer a DWG export over PDF, as the DWG preserves layer information, where when I just tested the PDF export, it did not. 

The DWG option has all the opportunities you listed above.