Bisection Search Like A (Human) Boss

Bisection search, or binary search for us developers, is a technique for finding the best value within a given range of values. This post describes tips for when you need to bisection search manually by hand (by “feel”), as opposed to when it can be automated by, say, a computer algorithm.

Bisection search, or binary search for us developers, is a technique for finding the best value within a given range of values.  Technically speaking, Wikipedia says the “bisection method in mathematics is a root-finding method that repeatedly bisects an interval and then selects a subinterval in which a root must lie for further processing.” This post describes tips for when you need to bisection search manually by hand (by “feel”), as opposed to when it can be automated by, say, a computer algorithm.

For example, say you’re very thirsty and need water fast so you pour yourself a glass of water: Pour too fast and it spills but too slow and it takes too long. You want to pour fast enough to quench your thirst as soon as possible but not so fast that it spills. The speed of pouring is your range of values (eg. slow to fast) and the consequences of the speed of pouring (how long it takes and if it spills) are your criteria to decide the best value. You try pouring the glass slowly and it’s too slow: Pour faster. You try pouring the glass faster and it spills: Pour slower but faster than the first time. You try pouring the glass “just right”: It’s fast enough and doesn’t spill. You’ve found the best pouring speed by bisection search!

Update 2017-10-26: Added sections: Bisection Hacks, and Case Study: Tuning Force Feedback Parameters in GTR2 – FIA GT Racing Game.

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Secrets of GTR2

Welcome to Secrets of GTR2 where I will be recording my experience, tips, tricks, resources and other helpful information as I get into GTR2.

Secrets of GTR2

Welcome to Secrets of GTR2 where I will be recording my experience, tips, tricks, resources and other helpful information as I get into GTR2.

Secrets of X is a series of blog posts I started with Secrets of iRacing and which has grown to include Secrets of GTR2, Secrets of Automobilista, and Secrets of rFactor 2. The “secrets” part is a little dramatic but there are quite a few tips and tricks I think new users will find very valuable and interesting.

Update 2017-11-10: Added Force Feedback > Guidelines for Tuning GTR2 Force Feedback. Updated Force Feedback > Rumble Strips Pushing/Pulling the Wrong Way to clarify wrong interpretation and now using default FFB parameter value.

Update 2017-11-09: Clarified Racing > Custom Daylight Acceleration works for regular race sessions but not 24 Hour races – they automatically time scale to race length setup when first starting the 24 Hour race.

Update 2017-11-08: Added Racing > Custom Daylight Acceleration. Added Resources > GTR Engineers Handbook and GTR2 Car-Owner’s Manual links. The GTR Engineers Handbook is particularly excellent for describe car setups better and more informatively than any in-game descriptions I’ve encountered before and the Q&A with real-life experts is also incredibly helpful.

Update 2017-10-31: Added Racing > How to Set AI Difficulty Level and Tips for Practicing and Qualifying for a Race sections. Also emphasized tip to avoid Time Acceleration as it causes a bug which results in overly quick AI lap times no matter what your AI difficulty level is set to.

Update 2017-10-29: Cleaned up and clarified Getting Started > Field of View. It’s now easy to understand and has an example. Fleshed out Force Feedback > My Personal Force Feedback Tweaking Notes with latest tuning adjustments.

Update 2017-10-12: Now using AI to AI Collision Rate=”40″ (max) as there’s no FPS loss for me so why not. Added Tips and Tricks > Avoid Time Acceleration to AVOID AI Bug.

Update 2017-09-22: Now using AI to AI Collision Rate=”32″ as I’m no longer experiencing FPS loss, maybe only stock tracks are affected and not HQ tracks. Try running HQ tracks if you have this problem. Added 5. Adding Friction and Damper under Force Feedback > My Personal Force Feedback Tweaking Notes. Added Force Feedback Settings under Getting Started > Modernizing as, while it may seem obvious, I wanted to highlight the need to do more than is available in-game to get closer to modern standards for FFB feeling. Added note about preferring HQ Cars and Tracks due to improved handling and grip adjustments in Getting Started > Modernizing > Mod: GTR2 HQ Mods Collection.

Update 2017-09-21: Added 4. Improving Corner Feeling under Force Feedback > My Personal Force Feedback Tweaking Notes.

Update 2017-09-17 – 2: HQ Cars & Tracks is working for me again after a fix. See comments under Modernizing > Mod: GTR2 HQ Mods Collection. Added Troubleshooting > Enable Tracing.

Update 2017-09-17: Added Troubleshooting section. Noted HQ Cars & Tracks was crashing for me. This works now, see comments under Modernizing > Mod: GTR2 HQ Mods Collection.

Update 2017-09-16: Added Tips & Tricks regarding turning up tire scrub and tire skid volumes and regarding refreshing old mod files if you’re experiencing instability.

Update 2017-09-15: Added Modernizing > 4GB Patch notes. Added GTR2 HQ CARS & TRACKS – 10th Anniversary and GTR2 HQ AI under Modernizing > Mod: GTR2 HQ Mods Collection. Added note that I’ve stopped using the Changing Weather Patch due to suspected instability.

Update 2017-09-14: Added Mod Spotlight > DTM Classics Mod with details for getting it running in 2017.

Update 2017-09-11: Detailed my FFB tuning in the section “My Personal Force Feedback Tweaking Notes”. Important! After a few rounds of FFB tuning I finally feel like I have a simple FFB setup that achieves car stability, quick response, and road feel. Added “GTR2 Crashes – It might Be Other Accelerated Graphics Apps” to the Tips and Tricks section.

Update 2017-09-08: Added “Disable Auto-pit and ai control” under the “Tips and Tricks” section. Noted tweaks in the “Make GTR2 Use More Cores For Better Performance” section under Performance. Added “My Personal Force Feedback Tweaking Notes” under the Force Feedback section.

Update 2017-09-06: Noted I’ve started over again from Julien Regnard’s FFB guide tuning FFB from baseline values instead of PLR defaults values under the “Helpful Guide for Advanced Force Feedback Tweaking” heading. Highly recommended. Don’t skip it like I did.

Update 2017-09-01 – 2: Added main section Performance and sub-section Make GTR2 Use More Cores For Better Performance to describe GTR2’s single-core use and how to get it to use more than a single core for better performance.

Update 2017-09-01: Added a Table of Contents for more convenient organization and to make it easier to find what you want.

Update 2017-08-30: Updated Force Feedback section to include more details on finding my optimal “FFB steer force average weight”, “FFB steer force exponent”, and “FFB rumble strip pull factor”. Also added “Force Feedback Tweaking Guide for Simbin Games by Julien Regnard” in Force Feedback section.

Update 2017-08-25: Added Changing Weather Patch mod under Modernizing section and added to Mod Spotlight. Updated my latest FFB settings in the Helpful Guide for Advanced Force Feedback Tweaking section.

Update 2017-08-20: Further FFB tweaking of “FFB steer force grip weight” which gives a feel of losing and gaining grip while cornering. Added Tips and Tricks section Use Auto-Clutch With Paddle Shifters. Added main section Mod Spotlight.

Update 2017-08-19 – 2: Added Getting Started sections: Mod: Track update for GTR2 Original Tracks, Mod: New GFX Mod, Field of View, Wheel Rotation and Wheel Lock, iRacing-like Brake Sensitivity for Potentiometer Pedals (eg. G27). Added Adding Game Cars, Tracks, Mods and More main section. Added Force Feedback main section with sub-section Helpful Guide for Advanced Force Feedback Tweaking.

Update 2017-08-19: Welcome to the initial posting of Secrets of GTR2! Check back from time to time as I add things and note the updates in this update box.

What is GTR2?

From the Wikipedia entry,

GTR 2 – FIA GT Racing Game is a sports car racing simulator developed by Blimey! Games and SimBin Studios (later Sector3 Studios) for the x86 PC and is a sequel to GTR. Since its release in September 2006, it has received widespread acclaim. The game simulates the 2003 and 2004 FIA GT Championship racing series.

And here’s the official game trailer,

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