• 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
Jiia

Computing normals

4 posts in this topic

What I want to do is add a normal calculation into my terrain editor. The normal won't be recorded, but will be converted to a float modifier for vertex color using a static directional light. In other words, I end up with just a float. What I would like to do is compute the normal of a vertex by using the surrounding vertex positions, rather than computing the normal for a triangle and averaging them out for each vertex. Does that make sense? Is it possible? My vertices are all aligned on a grid. Each vertex is exactly 32 points distance in the x and z (ground) axes from other vertices. The height of each vertex is really the only contributing change in normals. Would you simply start each vertex normal as pointed straight up, then average out the other vertex angles related to it? Like if the vertex to the left is lower than the current, the current normal leans left. Then the same for the right vertex, and so on. Add them all together and renormalize? Any advice?
0

Share this post


Link to post
Share on other sites
you can try and take the two diagonal vectors from neighbouring vertices and cross product those.

E = V[i+1][j+1] - V[i-1][j-1];
F = V[i-1][j+1] - V[i+1][j-1];
N = E x F;
N.Normalise();

with the added extra optimisations, given that it's a regular grid.
0

Share this post


Link to post
Share on other sites
I can't beleive I haven't rated you until now. I've just been assuming I had you maxed out already. Yet it only gives you four points, so it's like shining your headlights [grin]

I'm curious as to why you chose to cross the diagonal vectors? What about the straight directions? Would there be a problem in using those? I could cross both and average them.

I'll try it and see what happens [smile]
0

Share this post


Link to post
Share on other sites
Both are pretty, but the combined normals seem a little more defined. Here are some snaps just because I like wasting time. The best way to notice the difference is to use an image previewer and flip between them. The combined normal is on the right:

Free Image Hosting at www.ImageShack.usFree Image Hosting at www.ImageShack.us

It looks sweet. Thanks [smile]
0

Share this post


Link to post
Share on other sites
it all comes down to how fast this needs to be. If it's for real-time calculations, or for pre-processing (in that case, I'd average the triangle normals). Also how it compares with extreme cases (very sharp landscape features).

I used the cross-product for a cheap water effect (simple double-buffer filtering, some disruption, hey presto). The results were ok. Maybe you can go and have a look at water rendering techniques, and how they generate real-time super-fast normals, because they have to do that very very quickly.

I guess averaging the neighbouring vertices to pull the normal towards the lowest / highest would be also very cheap, but I don't know how good. Well, seems pretty good from your results.

BTW. Thanks for ++rating. If my rating didn't increase that much, it's probably becuse your own rating is a bit low. So I'll have to rate you up to rate me up :)

haa... there ya go. [grin]

[Edited by - oliii on May 7, 2005 8:36:33 AM]
0

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