• 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.

Archived

This topic is now archived and is closed to further replies.

Corillian

How do you calculate normals for a cube?

8 posts in this topic

Each corner of the cube has 3 vertices for the 3 touching faces. How do I get the normals for each vertice of each corner? Thank you for your help, -Corillian
0

Share this post


Link to post
Share on other sites
Those tutorials have nothing to do with per vertex normal calculations. Lesson 8 has nothing to do with normals and lesson 7 only discusses face normals briefly.
0

Share this post


Link to post
Share on other sites
a unit normal = vector / vector''s size . magnitude/size =
sqrt(x2 + y2 + z2). read up on cross product''s too. hope that helped.
0

Share this post


Link to post
Share on other sites
Take the average of the face normals of every face that uses the vertex.

There are better ways of calculating like weighting by face angle. You can read in the 3D Studio Max SDK how this method works.


Edited by - bobo on July 20, 2001 3:31:14 AM
0

Share this post


Link to post
Share on other sites
Each face has 4 vertices and 4 lines (vectors) ajoining them.
To calculate the normal get the cross product of
any 2 of the 4 vectors.
I have included code for a cube with the surface
normals stated explicitly.
This works for shading etc.
The normal to the top face is the unit vector pointing up
(0,1,0)
The normal to the bottom face is the unit vector pointing down
(0,-1,0) etc.
this draws a cube ready for shading
Hope it works

void DrawBox()
{
glPushMatrix();
glTranslatef(position.x,position.y,position.z);
glBegin(GL_POLYGON);
glNormal3f(0.0f, 1.0f, 0.0f); //top face Normal

glVertex3f(0.5f, 0.5f, 0.5f); // top face
glVertex3f(0.5f, 0.5f, -0.5f);
glVertex3f(-0.5f, 0.5f, -0.5f);
glVertex3f(-0.5f, 0.5f, 0.5f);
glEnd();

glBegin(GL_POLYGON);
glNormal3f(0.0f, 0.0f, 1.0f); // N front face

glVertex3f(0.5f, 0.5f, 0.5f); // front face
glVertex3f(-0.5f, 0.5f, 0.5f);
glVertex3f(-0.5f, -0.5f, 0.5f);
glVertex3f(0.5f, -0.5f, 0.5f);
glEnd();

glBegin(GL_POLYGON);
glNormal3f(1.0f, 0.0f, 0.0f); // N right face

glVertex3f(0.5f, 0.5f, 0.5f); // right face
glVertex3f(0.5f, -0.5f, 0.5f);
glVertex3f(0.5f, -0.5f, -0.5f);
glVertex3f(0.5f, 0.5f, -0.5f);
glEnd();

glBegin(GL_POLYGON);
glNormal3f(-1.0f, 0.0f, 0.0f); // N left face

glVertex3f(-0.5f, 0.5f, 0.5f); // left face
glVertex3f(-0.5f, 0.5f, -0.5f);
glVertex3f(-0.5f, -0.5f, -0.5f);
glVertex3f(-0.5f, -0.5f, 0.5f);
glEnd();

glBegin(GL_POLYGON);
glNormal3f(0.0f, -1.0f, 0.0f); // N bottom face

glVertex3f(0.5f, 0.5f, 0.5f); // bottom face
glVertex3f(0.5f, -0.5f, -0.5f);
glVertex3f(-0.5f, -0.5f, -0.5f);
glVertex3f(-0.5f, -0.5f, 0.5f);
glEnd();

glBegin(GL_POLYGON);
glNormal3f(0.0f, 0.0f, -1.0f); // N back face

glVertex3f(0.5f, 0.5f, -0.5f); // back face
glVertex3f(-0.5f, 0.5f, -0.5f);
glVertex3f(-0.5f, -0.5f, -0.5f); glVertex3f(0.5f, -0.5f, -0.5f);
glEnd();

glPopMatrix();


}
0

Share this post


Link to post
Share on other sites