Using the projection of a layer variable to project another in Model Builder in ArcGIS

Question

So in model builder I would like to have one input feature class projected to match the projection of another layer (a raster layer) that is a variable in the model. Can anyone help me achieve this?

Answer 1

Use the Calculate Value tool with a bit of arcpy to retrieve the coordinate system of your raster then pass it to the Project tool as an output coordinate system.

1. In model builder, connect your raster dataset as precondition to the Calculate Value tool

2. Within the Calculate Value tool's code block, add this

   def rasterPrj(raster):
     return arcpy.Describe(raster).spatialReference
   

3. Set the Data Type as Spatial Reference

4. Type this in the expression rasterPrj("%inRas%")