Some of the scripts and plugins I’ve been using.
Greeble the legendary detailing plugin. Great for mocking things up quickly.
Neil Blevin has a big useful script pack Soulburn Scripts. He also has and interesting blog.
wrapit is great for retopologising hi res meshes in max
BerconMaps procedural materials for Max: Wood, Noise, Tile, Gradient and Distortion. All of them are 3D maps except for Tile. They will work with scanline, V-Ray, finalRender and Brazil… BUT alas not Mental Ray.
clone is a free plugin that does what it says on the tin. I’ve been using it production. It’s stable and a great time saver.
Radial Symmetry not free but super cheap ($20) an awesome time saver and a great creative tool
