Bevel or Subdivision

So I was wondering which is heavier to render is it using subdivision or bevel? Because bevel actually increase the number of vert in the model while Subdivision only make it render that way. I’m new to blender and want to know which are better to use or should I suse both at the same time

Subdivision modifiers add extra geometry too. Even though it isn’t applied, the extra faces are there, and modifiers have to be temporarially “applied” for rendering. That means subdivisions can slow down rendering just as much as other geometry.

You’re thinking about how old Renderman and similar renderers of that generation worked, where they tesselated the mesh on the fly at render time. These techniques don’t work well with pathtracing, so now everything is subdivided before render and takes up more memory. Thank goodness we now have a lot more memory available :smiley:

In general, meshes using bevel will be quite a bit lighter than a model of the same complexity done with subsurfs. But bevels have their own set of problems. Just use whichever technique is more appropriate for the subject matter. There’s no golden rule.

Oh I see thanks for the reply! I’m new to 3D
Gonna try and learn when I should use bevel and when I should use 3D

Thanks!

Oh alright, that mean doesn’t matter which one I choose for smoothing edge or object, I think it come down to the which one should I use

Thanks for the reply!

Subdividing affects the whole mesh, bevelling just the edges selected.
When sub dividing each edge will be divided in two so any quad (four sided face) in your model is split into four faces. This has a big impact on complex models, even more so when using increased levels of subdivision. One face becomes 16, then 64 faces with two or three levels of subdivision.
You’ve probably noticed edges get rounded off too much when using subdivision, so you need to add support loops, extra edges running parallel to limit the bend. Bevelling edges is one way of doing this. Smooth subdivided curves and tighter corners where you want them.
Have a look at the Bevel Modifier and using Bevel Weights where you can pick which edges you want beveled in your final model, but keep the low detail model to work on. It’s far easier leaving them as modifiers (rather than actually bevelling them) if you want to edit that area of your model.