Fix crash when creating object instance without material
Fix crash when creating object instance without material

Aakash1312/appleseed,glebmish/appleseed,appleseedhq/appleseed,dictoon/appleseed,Vertexwahn/appleseed,dictoon/appleseed,Biart95/appleseed,aiivashchenko/appleseed,glebmish/appleseed,est77/appleseed,luisbarrancos/appleseed,aytekaman/appleseed,aiivashchenko/appleseed,glebmish/appleseed,est77/appleseed,pjessesco/appleseed,glebmish/appleseed,Vertexwahn/appleseed,pjessesco/appleseed,dictoon/appleseed,aytekaman/appleseed,Biart95/appleseed,luisbarrancos/appleseed,est77/appleseed,pjessesco/appleseed,est77/appleseed,dictoon/appleseed,aiivashchenko/appleseed,Biart95/appleseed,Vertexwahn/appleseed,aytekaman/appleseed,appleseedhq/appleseed,Biart95/appleseed,appleseedhq/appleseed,appleseedhq/appleseed,Aakash1312/appleseed,gospodnetic/appleseed,Biart95/appleseed,aiivashchenko/appleseed,Aakash1312/appleseed,appleseedhq/appleseed,dictoon/appleseed,est77/appleseed,gospodnetic/appleseed,gospodnetic/appleseed,luisbarrancos/appleseed,aytekaman/appleseed,Aakash1312/appleseed,Vertexwahn/appleseed,glebmish/appleseed,luisbarrancos/appleseed,aytekaman/appleseed,aiivashchenko/appleseed,pjessesco/appleseed,luisbarrancos/appleseed,gospodnetic/appleseed,Vertexwahn/appleseed,Aakash1312/appleseed,gospodnetic/appleseed,pjessesco/appleseed