AdvArray - 3ds Max Advanced Parametric Array Modifier
https://timbot.gumroad.com/l/AdvArray
The AdvArray modifier is an advanced parametric array type modifier for Autodesk 3ds Max. Being that 3ds Max does not ship with any sort of parametric array modifier, I’ve programmed this modifier to fill that void as well as add a number of advanced array features not found in 3ds Max by default, and even some that cannot be found in other third party modifiers.

MultiScatter is a plug-in for 3ds max which works with V-Ray, Mental Ray, Corona and Octane rendering systems. It is possible to create complicated scenes with a huge amount of objects easy and quickly with the aid of this plug-in.
IrayPlugins IFMAX v2.5.0-150830 MAX 2022
https://www.irayplugins.com/iray-for-3ds-max/
Bring your 3D designs to life with Iray for 3ds Max. With access to a comprehensive materials library, intuitive physically-based NVIDIA MDL material creation and real-world environments and lighting you can quickly achieve stunning images and animations of your designs. A range of integrated post-production features and fine tuning controls allow finishing touches and refinement for your final shots.

MultiScatter is a plug-in for 3ds max which works with V-Ray, Mental Ray, Corona and Octane rendering systems. It is possible to create complicated scenes with a huge amount of objects easy and quickly with the aid of this plug-in.
uPVC Sliding Door Generator v2.0 for 3ds Max
http://gumroad.com/l/sliding_door_generator
SLIDING/ STACKING DOOR GENERATOR is a script that is efficient in automatically creating 3D models of sliding/stacking door in 3dsMax. Containing many styles of window, it can be applied flexibly in Archviz projects while saving a lot of time for 3D artists.

Forest Pack is the world’s most popular scattering plugin for 3ds Max®. It provides a complete solution for creating vast areas of objects, from trees and plants to buildings, crowds, aggregates, ground-cover, rocks and more. If you can model it, Forest Pack can scatter it.

FloorGenerator is a plugin for 3ds Max (2013 to 2018) which generates floor objects consisting of individual boards which can easily be textured using MultiTexture. It's a great tool if you're doing architecture visualization and need to make floors that are NOT going to tile and that you can see up close without any pixilation.
TopoLogiK v1.12 for 3ds Max
https://hocuspocus-studio.fr/tools/product/topologik/
TopoLogiK is a new Retopology tool for 3dsmax.
It brings a more procedural, parametric and efficient approach to retopology in 3dsmax.
Some features are inspired from what you can see in other software like Blender or TopoGun.

http://hqdetails.com/shop/floorgen-tools
Make FloorGenerator even better

SolidRocks fully automates the complex setup of V-Ray. Professional Rendering in V-Ray never was easier.

SiNi Software is a developer of Autodesk® 3ds Max® plugins that minimise your time doing the tedious and boring stuff allowing you to focus on the creative work you enjoy.

http://www.guruware.at/main/
The Ivy Generator is one of those plugins which adds immense value to your work, yet it doesn’t cost you a dime. Believe me, this nifty little plugin is super easy to use, and has in-depth controls that would put even paid plugins to shame. Ivy Generator has been around for nearly a decade, giving 3ds Max users like us the ability to realistically simulate the growth of Ivy or Creeper plants in our scenes. Using such varied vegetation within the scene gives it that natural photorealistic touch. And using this plugin to its full potential is exactly what I’m going to be showing you today. In this guide I’ll be laying out all of its features in simple words, so you’ll be up and running in no time.
Thea for SketchUp is a combination of powerful rendering engines of Thea with the simplicity of SketchUp. Having biased, unbiased and interactive render modes including GPU support at your fingertips, inside SketchUp view, is a joyful experience. The plugin lets you enrich your models with highly detailed three dimensional content, breaking old limitations related to handled model complexity.

http://hqdetails.com/shop/floorgen-tools
Make FloorGenerator even better


Poliigon Leather Generator
http://www.poliigon.com/texture/leather-generator
The freedom to create the perfect leather for your furniture or clothing. No nodes or complexity, just artist-friendly sliders and dropdowns like; the leather species, coloring, patina, wrinkles, cracking and more. Learn more in the preview video or go here for more info on all our generators

DriveMaster for 3ds max
There are more than a few scripts and rigging tools available for rigging automobiles in 3ds Max. Some offer an easy way to get wheels rotating based on the movement of the car, others will add in steering, and even others will incorporate a suspension system.

http://www.splinedynamics.com/subspline/

Overnight Batch Render v1.03 for 3ds Max
http://www.scriptspot.com/3ds-max/scripts/overnight-batch-render
Overnight Batch Render is a simple yet powerful batch rendering tool for 3dsMax, capable to process multiple scene files sequentially on a single computer.

Weight Pro 2.01 for 3ds Max 2013 - 2021
https://km-3d.com/produkt/weight-pro-3ds-max-plugin/
WeightPro is a c++ 3ds Max plugin for automatic, fast and smooth Skin modifier weighting, no matter if the mesh has good or messy topology.
It voxelizes the mesh with the skeleton using GPU to calculate the shortest distances between bones and vertices. It allows you to make adjustments during posing in realtime.
After that you can delete the plugin from the scene and from now the skinned object is ready to use by everyone without the plugin.