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      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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mincomp

Question about getting collision normals from bvh

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Hi all,

I'm working on a small rigid body simulator, and this has been a long haunting problem for me: how do I get penetration normal from a bvh. Eventually, by traversing the structure, we can get all pairs of intersecting triangles, however we still don't know if each of the six vertices (from each pairs of triangles) are inside or outside the object itself, nor the normal to the object surface.

I thought I can solve this problem by using a signed distance field, where the inside test is straightforward and the normal can be acquired from discrete differentiation with near by cells, however, when constructing the distance field, I still need to know if a point is inside the object or not. I used to assume the object to be convex (and the problem is easy to solve), and when I move to concave objects, it seems to be very difficult. The ray shooting method is slow and not robust enough, what's worse is that I got some models that are not simple polyhedrons (meaning that the object has multiple components and there are welding edges between them, so that some triangles might be inside the object!)

So after all, my questions is: how to decide if a point is inside/outside the object with BVH, assuming the polyhedrons are normal (those irregular ones can be decomposed)? I know BSP can do this, however I believe BVH can do it as well, otherwise there won't be SO much literature about BVH-based collision detection, the weird thing is that almost nobody mentioned this problem among the literature I searched, am I just being paranoid to solve a irrelevant problem? The only reference I found about this problem is "A Fast Method for Local Penetration Depth Computation" from M.C. Lin, which is somewhat over complicated to me. A quick distance field construction reference is welcome as well.
Or are there other ways to pass around the problem and get the collision normals directly from BVH?

Many thanks in advance!!
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