• 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
ff8

gluLookAt()

6 posts in this topic

Hi, i am tring to make gluLookAt function to use it in my class but i face some problem like when i use gluLookAt(...) it give me a result and when i use my own test.LookAt(...) same value diffrent result
template <class T> view<T> &view<T>::LookAt(T eX,T eY,T eZ,
					    T cX,T cY,T cZ,
					    T uX,T uY,T uZ){
	Unit();
	V3D F,UP,s,u;	
	UP.set(uX,uY,uZ);
	F.set(eX-cX,eY-cY,eZ-cZ);
	F.normal();
	
	s.CrossProduct(UP,F);
	u.CrossProduct(F,s);
	s.normalize();
	u.normalize();

	this->arrMat[0]=s.x;
	this->arrMat[1]=s.y;
	this->arrMat[2]=s.z;
	this->arrMat[4]=u.x;
	this->arrMat[5]=u.y;
	this->arrMat[6]=u.z;
	this->arrMat[8]=F.x;
	this->arrMat[9]=F.y;
	this->arrMat[10]=F.z;
	this->MultMatrix();
	this->Translate(-eX,-eY,-eZ);

	return *this;
}

i use the same gluLookAt's code . bye
0

Share this post


Link to post
Share on other sites
hi,
when i use
gluLookAt(0,0,0,0,0,-1,0,1,0);
it works and i can see my triangle
and this is the modelview matrix after gluLookAt
0.894427 0 -0.447214 0
0 1 0 0
0.447214 0 0.894427 0
0.894427 0 -0.447214 1

but when i use
test.LookAt(0,0,0,0,0,-1,0,1,0);
empty scene the triangle dosen't show up :(
and this is the modelview matrix after test.LookAt
0 0 0 0
0 0 0 0
-0.4 0 0.8 0
0 0 0 1


[Edited by - ff8 on June 18, 2005 10:19:22 AM]
0

Share this post


Link to post
Share on other sites
I wrote this code to replace gluLookAt() ages ago. Virtually the same thing, 'cept it uses trigonometry instead of matrix operations, and you can get the rotations on the x and y axiis for sprites. ;)


//THIS IS A REPLACEMENT FOR gluLookAt.
//It requires 1 less argument (the 'up' vector), because the positive Y axis is
//always 'up', unless you rotate it on the Z axis, which you can do on your own.
//It will also fill the array with the rotation angles, that way you can counter-
//rotate things like sprites.
GLvoid doLookAtR(GLdouble eyeX,GLdouble eyeY,GLdouble eyeZ,GLdouble centerX,GLdouble centerY,GLdouble centerZ,GLdouble* rs){
GLdouble x = eyeX - centerX;
GLdouble y = eyeY - centerY;
GLdouble z = eyeZ - centerZ;

//lengths = 0, no difference = no rotation
if ((x == y) && (y == z) && (z == 0.0f)) return;
//if looking straight up or down (fix for the gimbal lock - as found in gluLookAt)
if ((x == z) && (z == 0.0f)){
if (y < 0.0f){//if looking straight up
glRotated(-90.0f,1,0,0);
}else{//if looking straight down
glRotated(+90.0f,1,0,0);
}
glTranslated(-x,-y,-z);
return;
}

GLdouble rx = 0.0f;
GLdouble ry = 0.0f;

GLdouble hypA = (x == 0.0f) ? z : hypot(x,z);
GLdouble hypB = (y == 0.0f) ? hypA : hypot(y,hypA);
if (z == 0.0f) hypB = hypot(x,y);

rx = toDegs(asin(y / hypB));
ry = toDegs(asin(x / hypA));

//rotate and translate accordingly
glRotated(rx,1,0,0);
if (z < 0.0f){
ry += 180.0f;
}else{
ry = 360.0f - ry;
}
glRotated(ry,0,1,0);
glTranslated(-eyeX,-eyeY,-eyeZ);

if (rs){
rs[0] = rx;
rs[1] = ry;
}
}




[EDIT]
If you don't need the rotational values, you can always remove the 'rs' bit, or use this:

GLvoid doLookAt(GLdouble eyeX,GLdouble eyeY,GLdouble eyeZ,GLdouble centerX,GLdouble centerY,GLdouble centerZ){
return doLookAtR(eyeX,eyeY,eyeZ,centerX,centerY,centerZ,0);
}

0

Share this post


Link to post
Share on other sites
Quote:
Original post by ff8
Hi, i am tring to make gluLookAt function to use it in my class but i face some problem like when i use gluLookAt(...) it give me a result and when i use my own test.LookAt(...) same value diffrent result
*** Source Snippet Removed ***
i use the same gluLookAt's code .
bye


Your rotation matrix isn't correct, you want the inverse of that. Or, in full, including the translation:


[ Sx Sy Sz -P.S ]
[ Ux Uy Uz -P.U ]
[ Fx Fy Fz -P.F ]
[ 0 0 0 1 ]
0

Share this post


Link to post
Share on other sites
hi
what are P.S,P.U and P.F ??and how can i calculate them ??
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