VisualModel: more useful debug message
VisualModel: more useful debug message

Former-commit-id: dd87ab185e460f3f171e449e476e24042fa4f5cb
hdeling/sofa,FabienPean/sofa,hdeling/sofa,FabienPean/sofa,FabienPean/sofa,Anatoscope/sofa,hdeling/sofa,FabienPean/sofa,hdeling/sofa,hdeling/sofa,FabienPean/sofa,hdeling/sofa,Anatoscope/sofa,FabienPean/sofa,hdeling/sofa,Anatoscope/sofa,FabienPean/sofa,FabienPean/sofa,Anatoscope/sofa,Anatoscope/sofa,Anatoscope/sofa,Anatoscope/sofa,hdeling/sofa,Anatoscope/sofa,hdeling/sofa,FabienPean/sofa,Anatoscope/sofa,hdeling/sofa,FabienPean/sofa