Hello, I'm trying to optimize my coffee table topology to run smoothly in Unity / Unreal Engine, but I don't know what's the best way to reduce the triangle count on the panel shown in the pictures. Which variation would be the optimal way to reduce the triangle count? Any tips would be appreciated.   (The materials are just placeholder & rendered in Eevee; glass shader courtesy of Eric Klein.)

The one with the fewest triangles.  Your modelling software should be able to tell you which one that is.  Or you can count by hand; just remember that each quad consists of two triangles.

53 minutes ago, a light breeze said:

The one with the fewest triangles.

I think it is not that simple?

I've heard long, sliver triangles perform worse than more triangles with larger angles. The reason is that less pixels within bounding rectangles are actually inside the triangles, so more pixel shader threads end up idle.

But i'm no expert here, maybe somebody can elaborate in detail, or correct me...

I would go with the best tradeoff between vertex count and area distribution, so 2 seems a reasonable choice.
Also divide the remaining quads along the shortest diagonal, otherwise you can still end up with very narrow triangles there.

Generally you want to avoid long thin triangles. You also don't want to have too many edges connected from a single vertex.

You also should completely convert all quads to tris, don't mix and match especially if you decide to bake as different rendering engines will triangulate in their own way which will cause errors.

Optimization for the sake of optimization is a waste of time especially with the hardware we have today and considering this object is so basic.

if its not a high poly object. why reduce it at all. do you know how to make a low poly version of a model