moving "forward" according to current rotation

Gav · Post by **Gav** » Mon Sep 06, 2004 11:54 am

basically i have a node that rotates when you press left/right and then want it to go forward/back when i press up/down, however I can't figure out how to move it forward/back relative to its current rotation.

i have already searched thru the documentation and tried various ways but with no success... so remember this is the BEGINNERS forum and dont tell me I should be able to figure it out because I CAN'T!!!

DarkWhoppy · Post by **DarkWhoppy** » Mon Sep 06, 2004 1:34 pm

Forward is a vector, to go backward, subtract instead of add.

forward = vector3df(sin( Node->getRotation().Y*PI/180.0f ), 0, cos( Node->getRotation().Y*PI/180.0f ) );
Node->setPosition( Node->getPosition() + forward*10.0f ); //move forward 10 units

Oz · Post by Oz » Mon Sep 06, 2004 3:12 pm

Ouch, too much math.

Look here
http://irrlicht.sourceforge.net/phpBB2/ ... php?t=3705

or here
http://irrlicht.sourceforge.net/phpBB2/ ... php?t=3708

Hope it helps!

DarkWhoppy · Post by **DarkWhoppy** » Mon Sep 06, 2004 6:15 pm

Oz wrote:Ouch, too much math.

Copy/Paste is too much math?

It's already there for you

Oz · Post by Oz » Mon Sep 06, 2004 6:21 pm

LOL

No I mean use matrix math. Matrices are your friend!
Thanks for your code, im sure it works great.

saigumi · Post by **saigumi** » Mon Sep 06, 2004 9:53 pm

This is something I've been working on as 2 of my test projects needs some sort of GetOrientation() function.

I've been trying to read more on how to get a vector form of orientation, but everything out there gives a very simple quaternion method that doesn't involve vectors.

I could swear the answer is some form of Orientation =YawVector + PitchVector + RollVector;

Oz - Enraged · Post by **Oz - Enraged** » Mon Sep 06, 2004 10:24 pm

Well you could try my matrix math, (the links above) if its not good enough then just dont use it. (At least I tried)

Bah! Im so mad at the moment!

Gav (at uni) · Post by **Gav (at uni)** » Tue Sep 07, 2004 1:06 am

matrices are not my friend they are my sworn enemy. .. Unfortunately they have to exist to some extent

i will try darkwhoppy's method when i get home and see how it goes...
eek! i've used 200% of my bandwidth at uni im gonna pay for this thru the nose at the end of semester...

arras · Post by **arras** » Tue Sep 07, 2004 1:43 am

here is function for moving in 3d space (works in 2d too):
http://irrlicht.sourceforge.net/phpBB2/ ... php?t=3608

saigumi · Post by **saigumi** » Tue Sep 07, 2004 2:19 pm

Dang.. I searched the forums for 3 hours yesterday for that post. Read through a lot of code from a lot of people (you, Oz, jox, mm, etc...)

I made a demo just like your spaceship one in Ogre about 2 years ago using straight matrix math, but haven't used it since so the knowledge all leaked out.

jox gave me the same answer and I used yours to clean up the code.

Code: Select all

irr::core::vector3df dir = irr::core::vector3df(0.0f,0.0f,OffSet); //Offset = Speed * Time Factor; for smooth animation
irr::core::matrix4 rotMatrix;
rotMatrix.setRotationDegrees(node->getRotation());
rotMatrix.transformVect(dir);
node->setPosition(node->getPosition() + dir);

Seems like this should be a function in irr::scene::ISceneNode... like setPositionRelativetoSelf() but I bet there is a better word already in the 3D dictionary.