diff --git a/3d-viewer/3d_rendering/3d_render_raytracing/c3d_render_createscene.cpp b/3d-viewer/3d_rendering/3d_render_raytracing/c3d_render_createscene.cpp
index 2a8ca074c3..c73c8e9b18 100644
--- a/3d-viewer/3d_rendering/3d_render_raytracing/c3d_render_createscene.cpp
+++ b/3d-viewer/3d_rendering/3d_render_raytracing/c3d_render_createscene.cpp
@@ -285,6 +285,7 @@ void C3D_RENDER_RAYTRACING::reload( REPORTER* aStatusTextReporter, REPORTER* aWa
     m_object_container.Clear();
     m_containerWithObjectsToDelete.Clear();
 
+    setupMaterials();
 
     // Create and add the outline board
     // /////////////////////////////////////////////////////////////////////////
@@ -697,7 +698,7 @@ void C3D_RENDER_RAYTRACING::reload( REPORTER* aStatusTextReporter, REPORTER* aWa
     if( m_boardAdapter.GetFlag( FL_SOLDERMASK ) &&
         (m_outlineBoard2dObjects->GetList().size() >= 1) )
     {
-        CMATERIAL *materialLayer = &m_materials.m_SolderMask;
+        const CMATERIAL *materialLayer = &m_materials.m_SolderMask;
 
         for( MAP_CONTAINER_2D::const_iterator ii = m_boardAdapter.GetMapLayers().begin();
              ii != m_boardAdapter.GetMapLayers().end();
@@ -1013,8 +1014,6 @@ void C3D_RENDER_RAYTRACING::reload( REPORTER* aStatusTextReporter, REPORTER* aWa
     unsigned stats_endAcceleratorTime = GetRunningMicroSecs();
 #endif
 
-    setupMaterials();
-
 #ifdef PRINT_STATISTICS_3D_VIEWER
     printf( "C3D_RENDER_RAYTRACING::reload times:\n" );
     printf( "  Reload board:             %.3f ms\n", (float)( stats_endReloadTime -
@@ -1399,6 +1398,13 @@ void C3D_RENDER_RAYTRACING::add_3D_models( const S3DMODEL *a3DModel,
     wxASSERT( a3DModel->m_Meshes != NULL );
     wxASSERT( a3DModel->m_MaterialsSize > 0 );
     wxASSERT( a3DModel->m_MeshesSize > 0 );
+    wxASSERT( aModuleOpacity > 0.0f );
+    wxASSERT( aModuleOpacity <= 1.0f );
+
+    if( aModuleOpacity > 1.0f )
+    {
+        aModuleOpacity = 1.0f;
+    }
 
     if( (a3DModel->m_Materials != NULL) && (a3DModel->m_Meshes != NULL) &&
         (a3DModel->m_MaterialsSize > 0) && (a3DModel->m_MeshesSize > 0) )
@@ -1558,6 +1564,8 @@ void C3D_RENDER_RAYTRACING::add_3D_models( const S3DMODEL *a3DModel,
             {
                 const CBLINN_PHONG_MATERIAL &blinn_material = (*materialVector)[mesh.m_MaterialIdx];
 
+                const float moduleTransparency = 1.0f - ( ( 1.0f - blinn_material.GetTransparency() ) * aModuleOpacity );
+
                 // Add all face triangles
                 for( unsigned int faceIdx = 0;
                      faceIdx < mesh.m_FaceIdxSize;
@@ -1598,8 +1606,6 @@ void C3D_RENDER_RAYTRACING::add_3D_models( const S3DMODEL *a3DModel,
                         m_object_container.Add( newTriangle );
                         newTriangle->SetMaterial( (const CMATERIAL *)&blinn_material );
 
-                        const float moduleTransparency = 1.0f - ( ( 1.0f - blinn_material.GetTransparency() ) * aModuleOpacity );
-
                         newTriangle->SetModelTransparency( moduleTransparency );
 
                         if( mesh.m_Color == NULL )
diff --git a/3d-viewer/3d_rendering/3d_render_raytracing/shapes3D/cobject.h b/3d-viewer/3d_rendering/3d_render_raytracing/shapes3D/cobject.h
index 0fedab60c2..db64bc2bb2 100644
--- a/3d-viewer/3d_rendering/3d_render_raytracing/shapes3D/cobject.h
+++ b/3d-viewer/3d_rendering/3d_render_raytracing/shapes3D/cobject.h
@@ -63,7 +63,12 @@ public:
 
     explicit COBJECT( OBJECT3D_TYPE aObjType );
 
-    void SetMaterial( const CMATERIAL *aMaterial ) { m_material = aMaterial; }
+    void SetMaterial( const CMATERIAL *aMaterial )
+    {
+        m_material = aMaterial;
+        m_modelTransparency = aMaterial->GetTransparency(); // Default transparency is from material
+    }
+
     const CMATERIAL *GetMaterial() const { return m_material; }
     float GetModelTransparency() const { return m_modelTransparency; }
     void SetModelTransparency( float aModelTransparency ) { m_modelTransparency = aModelTransparency; }