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# Removing vanishing point.

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Hi all-- I have a projection matrix that I set like this: void SetPerspectiveMatrix(LPD3DMATRIX mat) { double dTmp1; double dTmp2; double dHalfHeight; double dFrontClipping; double dBackClipping; #define HALF_HEIGHT D3DVAL(0.5) #define FRONT_CLIP D3DVAL(1.0) #define BACK_CLIP D3DVAL(5000.0) dHalfHeight=HALF_HEIGHT; dFrontClipping=FRONT_CLIP; dBackClipping=BACK_CLIP; dTmp1=dHalfHeight/dFrontClipping; dTmp2=dBackClipping/(dBackClipping-dFrontClipping); mat->_11=D3DVAL(2.0); mat->_12=D3DVAL(0.0); mat->_13=D3DVAL(0.0); mat->_14=D3DVAL(0.0); mat->_21=D3DVAL(0.0); mat->_22=D3DVAL(2.66); mat->_23=D3DVAL(0.0); mat->_24=D3DVAL(0.0); mat->_31=D3DVAL(0.0); mat->_32=D3DVAL(0.0); mat->_33=D3DVAL(dTmp1*dTmp2); mat->_34=D3DVAL(dTmp1); mat->_41=D3DVAL(0.0); mat->_42=D3DVAL(0.0); mat->_43=D3DVAL(-dHalfHeight*(dTmp2)); mat->_44=D3DVAL(0.0); } I essentially have copied it out of the DirectX sdk. But, I''m now writing a small editor to let me fine-tune my 3d-graphics, and I want a perspective projection without a vanishing point, so that I can look at things from the side without having more distant vertices approach the horizon. Does anyone know what changes I have to make to remove the vanishing point from my perspective? Thanks! -- Goodlife ----------------------------- Think of your mind as a door on a house. Leave the door always closed, and it's not a house, it's a prison. Leave the door always open, and it's not a house, it's a wilderness-- all the vermin creep in.

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Sorry if I''m confused, but do you mean an orthographic projection?

This is the only way I''m aware of not getting a vanishing point (unless you project everything outwards )

If your question went entirely over my head and I come across as a naive twat, please don''t hurt me.

Laters.

ps - If you want to know how to do a 2d projection, I''ll post the matrix here if you ask nicely.

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I think you mean the far clippingplane.
Increase the far clippingplane or use this function like I do:
D3DXMatrixPerspectiveFov(&matProj, fovy, aspect, zn, zf)
Hope it helped...

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Poontardis: Pleaaaase?

What I mean is this: With the matrix I have, things that are more distant from the camera tend to curve inward toward the origin, when projected in 2d.

I would like it so that if I have a vertex (xyz) at 1,1,1 and a vertex at 1,1,1000, they occupy the same pixel when projected in 2d, if I''m looking right down the Z plane.

-- Goodlife

-----------------------------
Think of your mind as a door on a house. Leave the door always closed, and it's not a house, it's a prison. Leave the door always open, and it's not a house, it's a wilderness-- all the vermin creep in.

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Orthogonal projection matrix

Q = 1/(Zf-Zn)

w   0   0   00   h   0   00   0   Q   00   0 -Zn*Q 0

- WitchLord

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