ZBrush to Houdini: Retopo and Polygrouping

Retopology and polygrouping techniques are essential parts of the hardsurface modeling workflow when using ZBrush, regardless of other DCCs you use. In this video, I wanted to point out how leveraging Houdini and Houdini Modeler 2025 to retopologize and establish polygroups that can then be transfered back over to ZBrush can be achieved, fast and easy. Here is the Vex code that I threw into an Attribute Wrangle ( running over the Detail attribute ) that I had placed into an HDA for ease of use ( copy everything between "CODE BEGINS and CODE ENDS", and replace LESSTHAN with a less than backet. Youtube hates angle brackets apparently :) : CODE BEGINS int success; dict polyMap = {}; for( int x = 0; x LESSTHAN nprimitives(0); x++ ) { vector cd = primattrib(0, "Cd", x, success ); string key = sprintf( "%f, %f, %f", cd.r, cd.g, cd.b ); if( !isvalidindex(polyMap, key)) { polyMap[key] = x; } int value = polyMap[key]; setprimattrib(0, "polygroup", x, value, "set"); } CODE ENDS Here is the link to the Modeler 2025 plugin: https://alexeyvanzhula.gumroad.com/l/jaoest 00:00 - Intro 00:40 - Start GoZ in Houdini 01:01 - Ctrl+Shift+C to Copy Subtool 01:14 - Ctrl+Shift+P to Paste into another Subtool 01:29 - Click GoZ button to send to Houdini 01:44 - Create a new Geometry node and dive in 01:47 - Drop a Labs GoZ Import Node 01:54 - Space+F to frame object 02:06 - Alt+W to start Retop with Modeler 02:30 - Create some more loops 02:38 - Select Build to reproject 05:25 - Pull out multiple faces 06:32 - Select Topo to stash construction history 06:58 - Drop Construction Plane 07:09 - Alt+F to bring up radial menu to Auto Flatten 07:37 - Hold V to snap Construction Plane to point 07:56 - Alt+C to bring up Color Radial Menu to Set Color 08:44 - Create polygroup attributes per color on appropriate primitives 09:21 - Drop GoZ Export Node 09:25 - Send to ZBrush 09:45 - Crease by Polygroup 10:01 - Set the Crease Level 10:38 - Copy subtool back to main model #houdini #houdinitutorial #zbrush #zbrushsculpting #retopology