# Triangles forming in a mesh with no triangles when rendering

it appears in both in cycles and blender render, there´s no difference between the preview and final render, whats causing it?, i don´t have triangles in my geometry

• It's possible also that the faces are non-planar. To check it select all, and choose Mesh > Clean-Up > Split Non-planar faces. If something changes with mesh then that's (one of) reasons. Most likely you will need to retopologize mesh. – Mr Zak Mar 10 '16 at 15:46

in a simple plain, when you move a vertex in a way that it can't be in a same height with other edges, blender creates an edge between edges to keep your shape as it is.
Take a look at this:

There is couple of ways to fix it, First you can add a little bit bevel to the mesh and then a subdivision to give blender more edges to play with(easier to do but heavier mesh).
Or you can add triangulate modifier and do some "edge rotate" on edges that you want to be in other direction. (lighter mesh but harder to do)

• thanks a lot, the bevel and subdiv solved it, it was as simple as that, thanks again for the help – Benjamin J. Mar 11 '16 at 3:43

Try removing doubles by selecting all and pressing w then remove doubles.

Also,you have ngons which is automatically converted into triangles when rendering,so if it is not flat it will appear like this,

• thanks for the insight, im a noob at blender and i was trying some hardsurface modelling, someone told me ngons doesn´t have a lot of impact in hard surface, i´ll have to polish my technique – Benjamin J. Mar 11 '16 at 3:45