Possible to use a Model Parameter to scale an Appearance Image

[mike.diyer]

I have an image of a "dot" that gets patterned in an appearance. So let's say it creates a pattern of (10) dots wide on my part. I would like to scale this image based on a calculation within the model parameters... So that the pattern could end up being (12, 15, 20) dots wide. Currently it looks like I can only put a "number" in the Image>Scale>Sample Size. 

[WCrihfield]

Hi @mike.diyer.  Unfortunately, no.  An 'appearance' is an Asset object when accessed by code, and those can exist within AssetLibraries, and within Documents.  But a Parameter only exists within a Document.  So the value must be independent of any specific Document.  I have one or more similar pattern based appearances that I use sometimes, but it is just based on an image of a single dot, or a symmetrical portion of one dot.  The size of the image can be specified to scale it.  Then when when I apply the appearance to a Face, the number of dots shown depends on the size of the face, due to image size/scale setting.  If I need larger and/or smaller size dots pattern, I simply use different Appearance with same image that is scaled differently, or use larger/smaller initial image size in other appearance.  Then change face to alternate appearance.