check return value of GetTexture (specular)

hw3d/Mesh.cpp

@@ -281,8 +281,10 @@ std::unique_ptr<Mesh> Model::ParseMesh( Graphics& gfx,const aiMesh& mesh,const a
 		material.GetTexture( aiTextureType_DIFFUSE,0,&texFileName );
 		bindablePtrs.push_back( std::make_unique<Bind::Texture>( gfx,Surface::FromFile( base + texFileName.C_Str() ) ) );
 
-		material.GetTexture( aiTextureType_SPECULAR,0,&texFileName );
-		bindablePtrs.push_back( std::make_unique<Bind::Texture>( gfx,Surface::FromFile( base + texFileName.C_Str() ),1 ) );
+		if( material.GetTexture( aiTextureType_SPECULAR,0,&texFileName ) == aiReturn_SUCCESS )
+		{
+			bindablePtrs.push_back( std::make_unique<Bind::Texture>( gfx,Surface::FromFile( base + texFileName.C_Str() ),1 ) );
+		}
 
 		bindablePtrs.push_back( std::make_unique<Bind::Sampler>( gfx ) );
 	}