how to fix light on reflective surface I rendered this musketeer sword and as you can see the light on the blade looks wrong and doesn't represent the actual shape.

so this is the solid view model with the blade in edit mode:



and this is the rendered version (please ignore the awful materials):


In case someone need it, this is the blender file : sword.blend
oh ok, it's because your plane is a little bit twisted (i.e. not really flat), you should rebuilt your mesh with a clean mesh structure (quads and edge loops). If you want to let it like it is you can quickly fix the problem with a trick: select the mesh and click on Properties > Data > Normals > Auto Smooth