Variable density of polygons to suit surface complexity..how ?

[Steve003]

Hi,
It strikes me that its wrong to choose ultra high to get the detail of items that sit on an otherwise smooth or slightly undulating surfaces. Take a vintage tractor, many smooth areas such as bonnet, sides, wheel hubs and rims, tyre sides (except for the lettering) cab structure, etc, with fasteners, wiring, and more detailed components showing lower on the sides, tread, axle joints etc.

How can one choose a setting to see a low poly count get used on smooth and a high poly count on detail.

I choose ultra high and get far more than I need, decimate attacks ALL polys and I lose the detail.

This is a fundamental need of the entire process and world of meshes AND EXTREMELY IMPORTANT.

How is this achieved, as I take the mesh into Rhino3D and its like wading through molasses, hellishly slow, when most of it doesnt need that density at all.

At times unworkable due to the speed hit, all for the detail parts I need on that tractor for example and I am looking at areas with far to many polys for what they need.

I dont see vids on this, everyone is doing rocks and aerial photos and fossils it seems.

Steve003