• 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

wondering if this is the right way to align the Yup to a direction

0 posts in this topic

Hi all.


At it again just thought I would try my hand at aligning rotation about  some axis based on a direction.


I create a plane at right angles to the direction vector facing it then I pick 3 of the points to obtain the axis between the two normals.


works ok but if I set the Position to the targets my mesh stops rendering or it vanished.


what sort of rotation is it, to do that.


here it the function any tips would be nice thanks.

//this will return a rotation matrix that will align a mesh that was created with y up to
//a direction aligns the meshes y with the direction
D3DXMATRIX AlignYupToDirection(D3DXVECTOR3 &pos, D3DXVECTOR3 &target)
	//holds our plane corrners
	D3DXVECTOR3 points[4];

	//we need to get the direction we are heading
	D3DXVECTOR3 dir = target - pos;

	D3DXVec3Normalize(&dir, &dir);

	//create a up vector
	D3DXVECTOR3 up = findPerpendicularIn3d(dir);

	float halfsize = 60.0;//any size may be larger

	D3DXVECTOR3 crossdirup;
	D3DXVECTOR3 crosso1dir;

	D3DXVec3Cross(&crossdirup, &dir, &up);


	D3DXVec3Normalize(&o1, &crossdirup);

	D3DXVec3Cross(&crosso1dir, &o1, &dir);

	D3DXVec3Normalize(&o2, &crosso1dir);

	//offset them
	o1 *= halfsize;
	o2 *= halfsize;

	//this is our plane at our position facing the direction we want
	//we only need 3 but not sure which ones yet
	points[0] = pos + o1 + o2;
	points[1] = pos + o1 - o2;
	points[2] = pos - o1 - o2;
	points[3] = pos - o1 + o2;

	//now using the plane we can create a axis to rotate about
	//we now need to use 3 points from the plane 
	D3DXVECTOR3 u , v, n, objn;
	int a = 0, b =1, c = 2;

	objn = D3DXVECTOR3(0.0, 1.0,0.0);//up


	//First convert the three points into two vectors
	u = points[b] - points[a];
	v = points[c] - points[a];
	//Step 2
	//Find the cross product of the vectors
	D3DXVec3Cross(&n, &v, &u);
	D3DXVec3Normalize(&n, &n);
	//step 3
	// Obtain axis between two normals, it will be the rotation axis
	D3DXVECTOR3 axis; 
	D3DXVec3Normalize(&objn, &objn);
	D3DXVec3Cross(&axis, &objn, &n);

	// Calc angle between normals
	D3DXVec3Normalize(&axis, &axis);

	FLOAT angle;
	float dot = D3DXVec3Dot(&objn, &n);
	Clamp(dot, - 1.0f, 1.0f ); 
	angle = acos(dot);

	// Create a quaternion with the rotation difference between normals
	//m_Inclination = Quaternion.CreateFromAxisAngle(axis, angle);


	return r;//done



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