• 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

What is demerit of using big Zfar value

3 posts in this topic

In a scenario I am rendering only two cubes one at z = 10 units and other at z = 100 units,

what difference does it make if I set

  • Zfar = 500 units
  • Zfar = 1000 units

Since the depth test will only check for fragments with common Z value and will render the cube at z = 10 units, does any of these Zfar values will provide same level of rendering optimization in this case or different ?




Share this post

Link to post
Share on other sites

As Brother Bob correctly pointed out, the ratio between zNear and zFar is the important thing [...]

Actually, that is only half the truth, and, in my opinion, the wrong half of the truth. It is not what I said, but, to be honest, I wasn't very explicit in what I meant either. What matters for precision is the ratio of the near clip plane and the objects you draw; the far clip plane plays a very small role, if not completely insignificant.


Let's say you have zNear=1, and zFar=100, and you draw the object at around z=10. Plug those values into the link you gave and it will tell you what precision you have at z=10 which is what matters if you want to draw an object at that depth. I used 10 depth buffer bits just to get some reasonably scaled values (plus the fact that 210 ~ 1000, so the depth resolution is easily related to percentages also so you can say how large percentage of the precision is distributed where); the depth resolution at z=10 is 0.095.


Now change zFar to something of several orders of magnitude larger, say 100000, and the depth resolution at z=10 becomes 0.096. So the near clip plane was pushed away with three orders of magnitude, and the precision changed by roughly 1% for the worse. Add another three orders of magnitude to the far clip plane, and the precision is virtually identical; the change is in the 7-8:th digit.


Now let's look at the near clip plane instead. Double the near clip plane, and watch the depth resolution at z=10 improve by roughly the same ratio.


So once the far clip plane is about 1000 times the near clip plane, its actual value is virtually meaningless and has no effect on precision. The near clip plane, and the ratio between the near clip plane and the objects being drawn, is everything.

Edited by Brother Bob

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