Append output not snapping to snap raster (Append in Iterator/Modelbuilder)

[Tabitha_NjeriKaranja]

I am having a problem with the output of an Append tool because the result is off 500m by 18m from the raster dataset in the snap raster environment of the modelbuilder.

Software: ArcGIS Desktop 10.6

Background: The Append tool is the last tool in the model. The model has an iterate feature selection which chooses features by name, performs calculations through an RC and then is supposed to append the result in an empty raster.

Problem: The result before and after the append is correct i.e. its data in the cell is correct on both accounts but the appended results shifts 500m to the right and 18m up. All snap and processing extent properties have been re-checked and are set correctly i.e in the modelbuilder and in the making of the empty append raster dataset.

Possible solutions done: many! Including running the model in the ArcCatalog, running it in the foreground in ArcMap, changing the Schema type in the Append tool, setting up the environment settings again in the Append tool (over and above the ones for the modelbuilder), reducing the results by 1000 (the result has many zeros), running iterator in a sub-model and the Append tool in a master model….but nothing seems to work. This last solution gave an error that one of the datasets during the beginning of the iteration can not be deleted. My last option left is to shift the whole appended dataset with the Shift tool.

Before I do this, I wanted to share and ask if there's anything am missing and what I can do to have the appended results snap to raster correctly (without the shift).

[curtvprice]

If you are using feature data in your Raster Calculator expressions, I recommend converting to raster first.  In general this tends to give you more control over the feature to raster conversion.  

I suggest avoiding the Append tool and use Mosaic or Mosaic To New Raster (or even Cell Statistics) instead to merge rasters. According to the help doc, Append does not honor the Snap Raster environment setting.

[Tabitha_NjeriKaranja]

The feature is used to extract by mask (boundary cut-out) but all the other datasets are rasters. Nevertheless, I understand the point made.

I have a storage constraint that is why I was avoiding inline model variable substitution but it looks like its the way to go and then merge the raster.

I had looked at the help doc for Append so many times and I did not understand that the point "This tool does not perform edge matching; there will be no adjustment to the geometry of features" means it does not honor Snap Raster environment setting. Is that right?

[curtvprice · Accepted solution]

Append is usually used for feature data not rasters. The snippet you copied from the help is discussing feature data. Note every tool help article has a section near the bottom that specifically lists which environments are used by the tool. 

The Mosaic tool can be used to append data into an existing raster, so you can use Mosaic the way you were using Append, with probably more success!