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      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
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Lambo

Ashikhmin-Shirley lightning model

4 posts in this topic

Hi, I'm trying to implement an anisotropic Phong BRDF lightning model [url="http://www.cs.utah.edu/~michael/brdfs/jgtbrdf.pdf"]http://www.cs.utah.e...dfs/jgtbrdf.pdf[/url]. Where specular component is defined as: [img]http://i44.tinypic.com/34yzqpz.png[/img]. I.m having problems with dot(n, h) exponent, because its numeric value is to big. Right now I think there is a problem with equation or my interpretation: according to the document Nu and Nv are freely chosen constants and can be equal, so if we chose Nu=Nv, exponent is equal to Nv whose value can range 1000, with is obviously to big and returns NaN in pow() function. Maybe someone can pinpoint my mistake?
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1000 is usually not too big for an exponent, so your mistake must be somewhere else located.
Best is you post your source code to make it easier to hunt down the prob.
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[quote]I.m having problems with dot(n, h) exponent, because its numeric value is to big[/quote]
This worries me. If your n and h are normalized, then dot(n, h) is in the range [-1,+1] so what you describe shouldn't happen.
Are you sure your vectors are normalized?
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Why not isolate the different parts of the equation?

Also, the pow function does not work with values below or equal 0 because the implementation is done with the equation exp(log(value) * value). Try to put something like this: max(dot(…), 0.0001f);

Good luck!!!
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Thanks guys! It simply was not normalized view vector, so my half vector was wrong... Paniced because if exponent would be 10000, base should not be smaller than 0.9913 or else outcome could not be expressed in sp float.
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