Fix re-run logic

stages/run_opensfm.py

@@ -147,7 +147,14 @@ class ODMOpenSfMStage(types.ODM_Stage):
             for band in reconstruction.multi_camera:
                 nvm_file = octx.path("undistorted", "reconstruction_%s.nvm" % band['name'].lower())
 
+                if not io.file_exists(nvm_file) or self.rerun():
                     img_map = {}
+
+                    if primary_band_name is None:
+                        primary_band_name = multispectral.get_primary_band_name(reconstruction.multi_camera, args.primary_band)
+                    if p2s is None:
+                        s2p, p2s = multispectral.compute_band_maps(reconstruction.multi_camera, primary_band_name)
+                    
                     for fname in p2s:
                         
                         # Primary band maps to itself
@@ -162,6 +169,8 @@ class ODMOpenSfMStage(types.ODM_Stage):
                                 log.ODM_WARNING("Cannot find %s band equivalent for %s" % (band, fname))
 
                     nvm.replace_nvm_images(tree.opensfm_reconstruction_nvm, img_map, nvm_file)
+                else:
+                    log.ODM_WARNING("Found existing NVM file %s" % nvm_file)
                     
         self.update_progress(85)