The Easyest DirectX Question i Ever hope to ask

Ok this is a simple one, i want to use LeftHanded CC

View

CamPos 0,0,-100

CamTar 0,0,0

CamUp 0,1,0

Now how do i get my projection matric such that (on a 1024x768 resolution)

0,0,0 in the world is the center of the screen

-512, 384 ,0 is top left of screen

512, 384 ,0 is top right of screen

-512, -384,0 is bottom left of screen

512 , -384,0 is bottom right of screen

Really simple question but i really dont know how to fine tune my projection matrix (at least i think thats what i need to modify)

And before you as the question yes i know about transformed Vertices and all that.... Thanks in advance

Ok this is a simple one, i want to use LeftHanded CC

View

CamPos 0,0,-100

CamTar 0,0,0

CamUp 0,1,0

Now how do i get my projection matric such that (on a 1024x768 resolution)

0,0,0 in the world is the center of the screen

-512, 384 ,0 is top left of screen

512, 384 ,0 is top right of screen

-512, -384,0 is bottom left of screen

512 , -384,0 is bottom right of screen

Really simple question but i really dont know how to fine tune my projection matrix (at least i think thats what i need to modify)

And before you as the question yes i know about transformed Vertices and all that.... Thanks in advance

im not too sure if you want to use a projection matrix for that..

d3ddev.transform.view = OrthoLH(1024,768, znearplane,zfarplane)

would do what you're asking

OrthoOffCenterLH would specify the bounds like (IIRC):

(left , right, bottom, top, znear,zfar)

like what you're asking for. (and with the arguments that you provided, the center = 0,0,0

but OrthoLH would make your 'center point' 0,0,0

its basically:

left = -width/2

right = width/2

top = -height/2

bottom = height/2

isnt the LookAt matrix masinly for 3d games?

here's my tip

in 2d: i transform the world, and set the view = orthoLH

in 3d: i dont worry aobut my center point, so my view = LookAt, and projection = ..(crap i completely forgot lol - its like PerspectiveFOVLH or something)

pent

Thanks Pent

I was just so used to 3d myself that id forgotten the finer points of view/projection/all that stuff. Thanks.

Are you sure?

d3d.Dev.Transform.View = Matrix.OrthoOffCenterLH(-512,512,-384,384,-50,0);

d3d.Dev.Transform.Projection = Matrix.PerspectiveLH(1024,768,-50,0);

Seems a little redundant to have Projection and View so simular and doesnt set campos,camtar,camup anywhere?!

Edit

After Testing doesnt seem to work, btw which Matrix makes it 10x larger in x,y?

Matrix.Scaling(10,10,1)

Matrix.Scaling(1/10,1/10,1)

Never Mind Problem was my cull mode Thanks Pent.

you're doing 3d right?

hmm,

ok, to set the center point to 0,0,0 - you'd have to set the camTarget to 0,0,0.. beucase that point will be the center of the screen

so just do

d3ddev.transform.view = matrix.lookatlh(campos, new vector3(0,0,0), new vector3(0,1,0)

d3ddev.transform.projection = matrix.perspectiveFOVLH( math.pi/4, 1, -50,0)

'math.pi / 4 is 45 degrees - so you can see "45 degrees around you",

the "1" represents the Aspect Ratio: most TV's use 16:9 which is widescreen (just type in 1.777 to get 16:9)

im not sure what PerspectiveLH is though

i beleive taht matrix.scaling (10,10,1) makes it 10x larger :)

pent

just wanna make a quick comment:

i dont think my reply was very clear lol

u said u want to makethe center point (0,0,0). in order to do that, just set the cameraTarget (0,0,0). becuase the cameraTarget is what you're looking at, and that point is the center of the screen

also, the greater the aspect ratio, the wider the objects will seem to appear

pent