Okino's 3D Polygon Reduction, Polygon Reducer and Part+Hierarchy Optimization System

You are here: Home » Specialized Sections » -Polygon Reduction

Sales: 1-888-3D-OKINO
Support: 905-672-9328

Okino's polygon reduction system comes for free with every copy of our industry standard PolyTrans (US$395) & NuGraf (US$495) programs. You can import/export from all major 3D file formats and produce excellent model compression up to 95%. Not only is it 1/2 to 1/10th the cost of other single-purpose polygon reduction programs from other companies, but you also get access to the most refined set of 3D import/export converters on the market, as well as rendering, scene manipulation and dozens of other features. The polygon reducer, as well as many other 3D mesh processing tools, can also be enabled during batch conversion of 3D files.

It also includes Okino's completely unique "parts count and hierarchy optimizer" which has formed the "black magic" in our software for decades - this takes a complex model and optimizes it for much faster real-time redraw performance (the optimizer is located in the 'Win' menu of the 'Selector Window'). The optimizer is available on most key Okino importers as the "Optimize Hierarchy" checkbox.

"I work at a Danish advertising agency where we have an inhouse 3D department producing a lot of 3D work for print and animation. I've found the Okino polygon reduction system to be a splendid tool which makes it easy to automate the process of making fantastic good-looking low-res models for animation with XSI and Maya. We use it to do a a lot of LEGO Bionicle visualisations, where we just parent rigid parts to joints, and put the hi-rez/low-rez parts in different display layers."

Martin Cohen, 3D Animator, ADVANCE

Introductory Overview

The Okino polygon reduction system is a mechanism that can greatly reduce the number of polygons in one or more 3D objects of a scene without greatly sacrificing object quality. It is a vital polygon optimization tool of the Okino PolyTrans and NuGraf software packages, which is included for free as part of the base level Okino software packages.

If you are a Maya or 3ds Max user and wish to utilize the polygon reduction system, first export out an Okino .bdf file using the special PolyTrans-for-Maya or PolyTrans-for-3dsMax plug-in systems, load that file into the stand-alone PolyTrans or NuGraf programs, perform the reduction, re-save the Okino .bdf file and re-load it into Maya or 3ds Max. There will be no geoemtry data loss in the process.

If a 3D model has a suffucient number of polygons in it then typical reductions are 80% to 95% while retaining good visual fidelity. The Okino polygon reduction algorithm implementation is based on the quadric error metrics (QEM) technique with added refinements based on 'wedge' techniques. These techniques try to retain the quality and appearance of the original model while reducing the overall number of polygons.

The following images show example polygon reduction results. The car is reduced 80% and the "turbine on plate" 95%, using the same techniques outlined in the online polygon reduction tutorials.

$image\cdrs1b_shg.jpg$		$image\cdrs2b_shg.jpg$
Original, 86154 triangles		80% reduction, 17143 triangles


Copyright: Model created by Gary Morales using CDRS software, an Evans and Sutherland product.

$image\pr_plt5_shg.jpg$		$image\pr_plt4_shg.jpg$
Original, 123276 triangles. 60MB memory to ray trace		95% reduction, 6692 triangles. 9.5MB memory to ray trace

Copyright: Model created by Genexis Design of Toronto, Canada

The polygon reduction system is described in several sections and online tutorials:

Overview of the Okino Polygon Reduction Algorithm
Polygon Reduction Tutorials
Step by Step Guide to Achieving Good Polygon Reduction
Hints and Tips for Using the Polygon Reduction Algorithm
FAQ's (Frequently Asked Questions)
Limitations and Gottchas
Dialog Box Option Descriptions
Academic Paper References About Polygon Reduction
Okino Algorithm Implementation, a Technical White Paper

How to Execute from within PolyTrans or NuGraf:

Method 1: Right click on any instance shown in the Selector window and click on the "Polygon Reduction" pop-up menu item. This will allow a single instance to be reduced.
Method 2: From the Geometry main menu, select the "Okino Polygon Reduction" option and then the "Reduce all objects in scene" sub-menu item. This will apply polygon reduction to every object defined in the scene.
Method 3: While in instance select mode (and not polygon select mode), select one or more instances in the Selector window. From the Geometry main menu, select the "Okino Polygon Reduction" option and then the "Reduce selected instances" sub-menu item. This will apply polygon reduction to only the instances currently selected.

Basic Parameters to Set:

To reduce the number of polygons in a model set you will typically change the "Polygon Reduction Amount" slider to select the desired percentage of reduction, then press the "Reduce!" button. After the model has been reduced press the "Exit" button to return to the main application.
It is also recommended that you enable the "Recompute new vertex normals" if you find that the resulting reduced model does not look good because of the resulting vertex normals (if you see black banding or sharp creases). Enabling this option, and using an appropriate smoothing angle, should produce very nice results.

When to Use

Use this algorithm any time you wish to reduce the number of polygons in a scene while retaining similar object quality and appearance. For example, you may have imported a CAD model with 1 million polygons which renders much too slowly; polygon reduction might bring this number down to 50,000 polygons with similar visual results after rendering. In general, any time you need to reduce the number of polygons in a scene then try using this algorithm - please read the tutorials so that you understand how to achieve the best possible quality.