Weird effect with lights

I’ve noticed a weird effect on some of my meshes. See the attached pictures below. Here’s the scene set up, both objects are mesh cylinders that I’ve “set smooth.” The light is a spot (only one in this scene, although I’ve detected this in many of my projects). The cylinders have a simple material (all defaults except the color).

The weird effect I don’t understand is that dark banding you see on the left-hand cylinder. I’ve learned how to get rid of it by toggling the “Auto Smooth” button in the Mesh editing panel. This is what I did to the right-hand cylinder. But now there is no noticable specular highlight on the object. (Same material!). (However, simply setting specularity to 0 in material does not negate the weird effect). I tried re-calculating the normals…no effect.

Can anyone offer some insight into this weird effect—what is it? How to better counter it (w/o losing specular)?

In advance, thank-you, I do.


Goto edit mode on the object, hit a for select all and press CRTL + N to recalculate the normals to the outside. It still might look funny at the top and bottom round edge because for some reason the stuff doesn’t like 90 degree angles on stuff when set smooth. You might have the chamfer the edge using edge loops to get it to look good.

Pardon the noob question…but is chamfer like bevel? And are edge loops the same as loop cuts?

thx agn

Yes chamfer is about the same as bevel you are correct. You are also right that the edge loop is the loop cut I’m talking about.

Although don’t use the bevel tool in blender, it will give you twice as many or more edges and lot’s of annoying triangles. Just take the edge loop (CTRL + R) and mouse over until you see the purple line cut across the side of the cylinder. Click once and then drag the new edge loop up towards the top edge and click again. Do the same for the bottom. Now select all the vertices at the very top round edge (alt + s click somewhere inbetween two vertices on the edge). Hit s for scale and shirnk the top ring just a little. Do the same on the very bottom edge. Hope this helps.