Billboarding

[danday1974]

Hi every1

Here is some DX8 bilbboarding code wrotten in VB. It doesnt work . Well it does but not 100% properly. Can any1 debug it please? Its difficult to explain what is gping on but if u look at the project u will get a better understandsing. PS I think the problem lies with the matrixBBFixedY function or with the call to that function. The second argument passed to that function I think should be the centre of the bllboard. Maybe I am passing the wrong value to the function?

Cheers for any help

Dan

[Zaei]

Yep, It was that function. Change one line to this:

.m22 = 1

You can figure out which line =).

It also seems that you should pass in the BOTTOM center of the billboard for it to work correctly.

Z.

[Zaei]

In fact, simply pass 0, 0, 0 in for the "center". This could be incorrect, It will take some testing to figure out =).

Z.

[danday1974]

Z

Thanks for your help I had pretty much given up on billboarding . With the Y axis fixed billboard the alteration u said made everything wok 100%. I think the second parameter passed is actually a translation vector (I think that is the right word for moving something).

Changing the code to .m22=1 does not work for a billboard where none of the axis are fixed however. Do u know this code please?

Cheers for sorting the Y-Axis fixed BB out for me

Dan

[Zaei]

No, the not locked billboard function works fine. The change was ONLY to the Locked function, because that function was incorrect, which is why it didnt work right.

Z.

[Zaei]

And you are right, it IS a translation vector. The way I use the function, I create a billboard centered on the origin, and then use that vector to do the translation.

Z.

[danday1974]

Im with u. Ive tried doing that now and got a nice forest of trees by translating the 'same' tree many times. I am still having troubles with the other billboarding function though (the billboard that is not fixed on any axis). I have not altered .m22 as I did in the FixedYBB function but after some testing it appears to 'sink' if u change the 'GroundLevel' variable.

Any ideas on this 1 please?

Thanks

Dan

PS The normal BB function is in the code I posted. To use it all u have to do is uncomment the call to the function so u can see the problem.

[Zaei]

Yeah, since your billboard is not centered on the origin, the rotations get a bit screwy. Try creating the billboard arend the origin, and then using the translation vector to move it.

Z.

[danday1974]

Z

Cheers for the advice

I will try it out

Thanks

Dan