Option Inputs in Modelbuilder.

Question

I have a model that takes three inputs (waterbodies, streams/river polyline, and streams/rivers polygon). It takes each one of these inputs, buffers them, merges all three buffer outputs to a single layer, and then deletes the area of the input features leaving only the buffer area.

Id like to make it so that this model could still be run if the user decided to only input two out of the three layers because there just so happens to be no waterbodies in the focus area.

I'm having a bit of trouble figuring out if this is possible in modelbuilder. I could likely easily accomplish this in python but first wanted to check here to see if anyone had any ideas.

Thanks!

Ben

DanPatterson_Retired · Answer

I thought you could have a layer participating in two streams of a workflow (in essence duplicating its input) being optional for one stream and its clone required for another.  In such an example you wouldn't have two branches eminating from the water layer, but two waterlayers, one going one way and the other going elsewhere.  (of course, I don't use MB much, but the logic makes sense)

BenjaminMittler · Answer

Thanks Dan,

That was the first thing i looked at. It wont let me change any of my parameters to optional. I think it may be because other processes rely on them  (the part where it erases the input features from the buffer).

However, if the above was true and it was because other processes relied on the inputs, i would think that i would be able to set the polyline stream/river input to optional because it has no other processes relying on it.  (didnt need to set up erase process since it was a polyline layer)

Any other ideas?

DanPatterson_Retired · Answer

make the water bodies layer an optional parameter

Changing model parameter type—Help | ArcGIS for Desktop