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DarkOwnt
05-03-2018, 03:48 AM
What are the maximum internal resolutions for the head and grain of a custom brush? It seems one can import textures of any reasonable size, but that there is also down sampling to some maximum resolution. What is it?

DarkOwnt
05-08-2018, 03:17 AM
Does anyone know the answer to this?

HannahRage
05-08-2018, 03:54 PM
ArtRage doesn't adjust your image, but it will use the fullsized image for the 100% brush size. This means that if you import two different head images, they will be two different sizes at 100%, and if you increase the stroke size to 200%, you will be scaling the image up with possible quality loss.

Your actual results will vary widely depending on your settings (e.g. does the grain scale or remain fixed), but check it at 100% to see if it is still the correct resolution. We do recommend keeping image sizes under 400x400 pixels to keep the memory usage down (you are painting with potentially hundreds of images in a row, large brushes could get very slow), but you can add larger head/grain images for specific purposes.

If it is too large to be easily workable, you may be better off using a custom canvas pattern or the Pattern Fill, or a stencil. As these are 'one use', you will have fewer memory issues compared to painting multiple strokes with a giant image. E.g. Use your custom brush without the grain, add the dabs,use 'Edit > Select Layer Contents' (not Lock Transparency) on the layer, use Pattern Fill to add the grain.


If you see something different, send us a specific example so we can check what is happening and if it's intended. You tend to experiment with interesting obscure edge cases so you may well have found something new ;)

DarkOwnt
05-08-2018, 11:34 PM
Thank you for the reply.

I think I had some incorrect assumptions about how the grain interacts with each brush dab. I assumed the grain acted as a mask prior to application of the head to the canvas and that the interaction was calculated at the higher resolution of the two. i.e. a 30x30 soft head could be used with 1000x1000 grain, and the result that I expected to see would contain all the information (not downsampled) of the 1000x1000 grain.

Is it possible what I am seeing is the interaction rescaling to the lower resolution of the two instead of the higher resolution?

Glad to hear there are no real limits to the size of these... it might just mean I need to tweak it to get what I am looking for.

If I'm stumped I'll post what I am seeing... something I like to do anyway.


:)

DarkOwnt
05-09-2018, 03:33 AM
Thank you for the reply.

I think I had some incorrect assumptions about how the grain interacts with each brush dab. I assumed the grain acted as a mask prior to application of the head to the canvas and that the interaction was calculated at the higher resolution of the two. i.e. a 30x30 soft head could be used with 1000x1000 grain, and the result that I expected to see would contain all the information (not downsampled) of the 1000x1000 grain.

Is it possible what I am seeing is the interaction rescaling to the lower resolution of the two instead of the higher resolution?

Glad to hear there are no real limits to the size of these... it might just mean I need to tweak it to get what I am looking for.

If I'm stumped I'll post what I am seeing... something I like to do anyway.


:)

My suspicions were wrong... something is downsampling the grain.

This is a small portion of a 2500x2500 image used as a grain
95148

This is the resulting grain resolution when used in a custom brush
95149


To generate the grain clearly I use the following, 0 dab spacing, 100 dab opacity, 100 grain size, 100 grain progression, 0 Size with head, 0 rotate with head

NOTE: Although I have posted no photos, the same thing happens to the brush head, if I use the 2500x2500 image file as a brush head, even at 500 brush size, it is apparent that down sampling has been used, the "AS" generated by the brush head has the same low sampling as the "AS" pictured above.


Something is limiting the achievable resolution of the grain and the brush head, I'd like to know what that limit is so can tailor the brush head and grain files to the proper resolution.

:)

DaveRage
05-09-2018, 10:55 AM
Sorry, just a quick correction: It's clamped to 400 x 400 pixels

DarkOwnt
05-09-2018, 11:33 AM
ah! mystery solved. Thank you!!!