Some basic questions about polygons

hi guys !

i have some very basic question about polygons in ue4

  1. how can i see the numbers of polygons in a model

  2. what is difference between Triangles and Polygons ?

3)how can i see the numbers of polygon in a destructible mesh in every depth (and totally) ?

Thanks alot

I can answer the first two. I havnt worked with destructable meshes in UE4 yet.

Double click any mesh in content browser to open the mesh editor and you will see this. The number of verts and tris for the model. Divide the tris in half to get the number of polygons.
The difference is this. Every face of a model consists of either Triangles, Polygons (usually called quads or ngons). So most 3d model applications make objects by quads (a face with 4 verticies) and they support faces with more than 4 verticies (ngons short for polygonals) game engines always convert quads and ngons to triangles because they perform more accurately for rendering textures and lighting. It is not as important as it used to be to watch poly count with the faster GPUs handling all those calculations, now the important thing to watch is shader complexity. Still doesnt hurt to keep your models as low poly as possible without sacrificing too much detail.