Spline FFD

MW RoofGen 2 generates hip roof geometry from any closed spline outline in 3ds Max. Pick a shape, set a roof angle, and hit Create, with optional UV generation for tile textures.

miauu's Spline Deformer is a commercial script for 3ds Max that lets you manipulate rows of edges as if they were splines. It works with Editable Poly objects and the Edit Poly modifier, with Soft Selection support.

DesignToolBox by Atelier Bump is a collection of tools for 3ds Max built to accelerate and simplify basic modeling tasks for architectural models, furniture design, and other work where accurate modeling is needed.

Polyline Pro is a spline-drawing tool for 3ds Max that creates splines precisely using measurements and angles, in a manner similar to AutoCAD. It offers Orthographic, Polar, Arc and Freehand drawing modes.

TerrainAxe is a 3ds Max toolset for building accurate terrain landscapes. It groups tools for smooth roads, flyovers, bridges, stairs, pavements, clearings and handrails into eight feature categories.

DesignToolBox is a collection of modeling tools for 3ds Max, built to accelerate and simplify basic modeling tasks for architectural models, furniture design, and other work where accurate modeling is needed.

Sweep Profile is a 3ds Max tool from KSTUDIO for building architectural profiles with the Sweep modifier. It ships with pre-made profiles and lets you add your own from the scene or a folder.

SplineOffset is a modifier for Autodesk 3ds Max that clones and offsets splines, creating multiple clones with incremental offset, translation, and rotation. It works fully non-destructively and can heal overlapping splines.

FAST ARCHITECTURE Trial is a procedural mesh object for 3ds Max that generates architectural structures with parameters you can adjust in real time. It creates an FA_Building object usable like any standard 3ds Max object.

Scatter by SiNi Software is a free 3ds Max tool for distributing 3D geometry across large surfaces. Add objects, proxies and cache files, then use a distribution map that can place up to one million points.

Explode Geometry is a 3ds Max plug-in that breaks one or more selected scene nodes into individual three- or four-sided faces, with options to add modifiers and refine the resulting geometry.