diff --git a/source/MRCuda/MRCudaFastWindingNumber.cpp b/source/MRCuda/MRCudaFastWindingNumber.cpp
index e86359f05c01..b968913ca957 100644
--- a/source/MRCuda/MRCudaFastWindingNumber.cpp
+++ b/source/MRCuda/MRCudaFastWindingNumber.cpp
@@ -124,10 +124,10 @@ Expected<void> FastWindingNumber::calcSelfIntersections( FaceBitSet& res, float
     } );
 }
 
-Expected<void> FastWindingNumber::calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, ProgressCallback cb )
+Expected<void> FastWindingNumber::calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, const ProgressCallback& cb )
 {
     MR_TIMER
-    if ( auto maybe = prepareData_( {} ) )
+    if ( auto maybe = prepareData_( subprogress( cb, 0.0, 0.5f ) ) )
         return unexpected( std::move( maybe.error() ) );
 
     const auto getCudaMatrix = [] ( const AffineXf3f& xf )
@@ -145,7 +145,7 @@ Expected<void> FastWindingNumber::calcFromGrid( std::vector<float>& res, const V
     const size_t size = size_t( dims.x ) * dims.y * dims.z;
     DynamicArrayF cudaResult;
     CUDA_LOGE_RETURN_UNEXPECTED( cudaResult.resize( size ) );
-    if ( !reportProgress( cb, 0.0f ) )
+    if ( !reportProgress( cb, 0.6f ) )
         return unexpectedOperationCanceled();
 
     fastWindingNumberFromGrid(
@@ -153,11 +153,11 @@ Expected<void> FastWindingNumber::calcFromGrid( std::vector<float>& res, const V
         cudaGridToMeshXf,
         data_->dipoles.data(), data_->cudaNodes.data(), data_->cudaMeshPoints.data(), data_->cudaFaces.data(),
         cudaResult.data(), beta );
-    
     CUDA_LOGE_RETURN_UNEXPECTED( cudaGetLastError() );
+    if ( !reportProgress( cb, 0.7f ) )
+        return unexpectedOperationCanceled();
 
     CUDA_LOGE_RETURN_UNEXPECTED( cudaResult.toVector( res ) );
-
     if ( !reportProgress( cb, 1.0f ) )
         return unexpectedOperationCanceled();
     return {};
diff --git a/source/MRCuda/MRCudaFastWindingNumber.h b/source/MRCuda/MRCudaFastWindingNumber.h
index 0545aae5e3ea..79f8c2821a25 100644
--- a/source/MRCuda/MRCudaFastWindingNumber.h
+++ b/source/MRCuda/MRCudaFastWindingNumber.h
@@ -26,7 +26,7 @@ class MRCUDA_CLASS FastWindingNumber : public IFastWindingNumber
     // see methods' descriptions in IFastWindingNumber
     MRCUDA_API Expected<void> calcFromVector( std::vector<float>& res, const std::vector<Vector3f>& points, float beta, FaceId skipFace, const ProgressCallback& cb ) override;
     MRCUDA_API Expected<void> calcSelfIntersections( FaceBitSet& res, float beta, const ProgressCallback& cb ) override;
-    MRCUDA_API Expected<void> calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, ProgressCallback cb ) override;
+    MRCUDA_API Expected<void> calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, const ProgressCallback& cb ) override;
     MRCUDA_API Expected<void> calcFromGridWithDistances( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, const DistanceToMeshOptions& options, const ProgressCallback& cb ) override;
 
 private:
diff --git a/source/MRMesh/MRFastWindingNumber.cpp b/source/MRMesh/MRFastWindingNumber.cpp
index c710b2ceeddc..802bbdeffe04 100644
--- a/source/MRMesh/MRFastWindingNumber.cpp
+++ b/source/MRMesh/MRFastWindingNumber.cpp
@@ -51,7 +51,7 @@ Expected<void> FastWindingNumber::calcSelfIntersections( FaceBitSet& res, float
     return {};
 }
 
-Expected<void> FastWindingNumber::calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, ProgressCallback cb )
+Expected<void> FastWindingNumber::calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, const ProgressCallback& cb )
 {
     MR_TIMER
 
diff --git a/source/MRMesh/MRFastWindingNumber.h b/source/MRMesh/MRFastWindingNumber.h
index 097dc2b8e395..d675d3eeb54e 100644
--- a/source/MRMesh/MRFastWindingNumber.h
+++ b/source/MRMesh/MRFastWindingNumber.h
@@ -36,7 +36,7 @@ class IFastWindingNumber
     /// <param name="dims">dimensions of the grid</param>
     /// <param name="gridToMeshXf">transform from integer grid locations to voxel's centers in mesh reference frame</param>
     /// <param name="beta">determines the precision of the approximation: the more the better, recommended value 2 or more</param>
-    virtual Expected<void> calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, ProgressCallback cb = {} ) = 0;
+    virtual Expected<void> calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, const ProgressCallback& cb = {} ) = 0;
 
     /// <summary>
     /// calculates distances with the sign obtained from generalized winding number in each point from a three-dimensional grid;
@@ -61,7 +61,7 @@ class MRMESH_CLASS FastWindingNumber : public IFastWindingNumber
     // see methods' descriptions in IFastWindingNumber
     MRMESH_API Expected<void> calcFromVector( std::vector<float>& res, const std::vector<Vector3f>& points, float beta, FaceId skipFace, const ProgressCallback& cb ) override;
     MRMESH_API Expected<void> calcSelfIntersections( FaceBitSet& res, float beta, const ProgressCallback& cb ) override;
-    MRMESH_API Expected<void> calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, ProgressCallback cb ) override;
+    MRMESH_API Expected<void> calcFromGrid( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, float beta, const ProgressCallback& cb ) override;
     MRMESH_API float calcWithDistances( const Vector3f& p, const DistanceToMeshOptions& options );
     MRMESH_API Expected<void> calcFromGridWithDistances( std::vector<float>& res, const Vector3i& dims, const AffineXf3f& gridToMeshXf, const DistanceToMeshOptions& options, const ProgressCallback& cb ) override;