Triangular artifacts in render

I’ve only used Blender for a few days, and would like some help.

I’m trying to render a mesh from an equation plotted in 3D using Maple and then exported as a COLLADA mesh. A section of it is shown here:

When Blender rendering it , I get triangular artifacts. These look like they correspond to diagonals joining each face in the mesh.

Choosing smooth, instead of flat, shading for the mesh, reduces the artifacts, but they don’t disappear entirely.

Is there any way to eliminate these artifacts completely?

As I said, I’m new to Blender so it may be something incredibly simple, but Google didn’t offer any immediately obvious solutions. Thanks.

Tried with a simple object created in Blender. Those are some kind of artifacts. Could be something related to ngons.

Have you tried BI’s bias option, they look very similar to the common terminator artifacts found on spherical objects when they are not subdivided enough.

Use a subsurf modifier or, at least, add a loop cut in the middle. And, of course, use smooth shading. Flat shading on such a curvy surface… Really? :smiley:

The subsurf modifier is really the easiest way, it will adapt to any shape and you won’t have to modify the shape by hand. You will however need to set the crease of the contour of the whole shape to 1 so that it doesn’t deform. Use [CTRL E] (Edge menu), [SHIFT E] (Crease function) or look somewhere in the [N] panel, I think.

This happens because quads are bend to two triangles. Smooth shading will fix the shading itself but shadows are still calculated from the raw geometry… As it’s been said, add subdivision surface. To preserve your outlines of the object, edge select them in edit mode and use CTRL E to make them bright purple :slight_smile:

Also make sure that you have no duplicate vertices. Simply press W in edit mode and select Remove doubles. You’ll see if any vertices are removed in the top menu next to render engine selection.

It is a well known ray tracing issue; the ‘terminator problem’. It is caused by self shadowing.

Change the lighting to brighten the shaded areas.