• Announcements

    • khawk

      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.
Sign in to follow this  
Followers 0

Orbit Quaternion Camera

2 posts in this topic

I'm trying to create a quaternion based camera to rotate around a given point in space. For that, I'm using spherical coordinates and  I've managed to position and calculate the look at vector correctly. However, the camera tilts and completely rolls over at a specific point, while always facing the target point.


The camera's parameters are:


T - the target position.

r - the distance from T.

theta - the pitch angle.

phi - the yaw angle.


The camera position P is easily calculated by spherical to cartesian coordinate conversion.

The view vector is, then, T-P. 


How can I create a quaternion that won't tilt and still face the target position. 


Thanks in advance


Share this post

Link to post
Share on other sites

That's exactly what I mean. Sorry for not being clear.


I have tried that but, for some reason, I wasn't successful. Here's my take on it.

glm::vec3 camPos(r*cos(yaw)*sin(pitch),
glm::vec3 viewVector = target - camPos;
glm::vec3 upVector(0,1,0);
glm::vec3 right = glm::cross(viewVector, upVector);
upVector = glm::cross(right, viewVector);
viewVector = glm::normalize(viewVector);
upVector = glm::normalize(upVector);
right = glm::normalize(right);

glm::quat rotation;
rotation.w = sqrtf(1 + right.x + upVector.y + viewVector.z) * 0.5f;
float w4_recip = 1 / (4*rotation.w);
rotation.x = (upVector.z - viewVector.y) * w4_recip;
rotation.y = (viewVector.x - right.z) * w4_recip;
rotation.z = (right.y - upVector.x) * w4_recip;



I have messed around with the camPos calculation and tried several different things.


Unfortunately, I'm not the best person at maths and most of the camera, transformation and rendering code is my own, and might as well have bugs. However it hasn't given me much problems until now. If this code is (mostly) correct, I have to search elsewhere for the problem.


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
Followers 0