Speedup w-shape-functions

Signed-off-by: Nicola Vigano <nicola.vigano@esrf.fr>

zUtil_Deformation/gtDefShapeFunctionsFwdProj.m

@@ -47,6 +47,9 @@ function shape_funcs = gtDefShapeFunctionsFwdProj(sampler, varargin)
     voxel_sampling = voxel_size ./ space_res * conf.factor;
     if (use_numinterp)
         voxel_sampling(3) = voxel_sampling(3) ./ conf.num_interp;
+        if (strcmpi(conf.shape_function_type, 'w'))
+            voxel_sampling(1:2) = voxel_sampling(1:2) ./ conf.num_interp;
+        end
     end
     voxel_sampling = max(ceil(voxel_sampling), 5);