Drawing Curves and Lines

thomascheah · Post by **thomascheah** » Fri Nov 02, 2007 10:23 am

1. How do I draw a curves (both 2D and 3D) in Irrlicht?

2. How do I draw lines with different thickness in Irrlicht?

Thanks!

hybrid · Post by **hybrid** » Fri Nov 02, 2007 11:27 am

which kind of curves do you need? There is no spline support in Irrlicht as of now, but you can use the linestrip primitives to approximate curves (manually).
Line thickness can only be done using OpenGL, DX does not support line thickness (we will have to mimick it with small polygons, but that will be done much later).

Namek Kural · Post by **Namek Kural** » Tue Nov 06, 2007 7:41 pm

Is there no way to draw a spline? I need one for the FollowSplineAnimator

Halifax · Post by **Halifax** » Tue Nov 06, 2007 8:12 pm

How about, a bezier(however you spell that) cure?

Namek Kural · Post by **Namek Kural** » Tue Nov 06, 2007 8:15 pm

bezier(however you spell that)

That was right!

Is it possible to use these bezier curves as splines for FollowSplineAnimator?

Halifax · Post by **Halifax** » Tue Nov 06, 2007 9:02 pm

No I was saying, implement your own bezier curves, and your own animator. It wouldn't really be that hard, and then you could also write a plugin for irrEdit to use it.

hybrid · Post by **hybrid** » Tue Nov 06, 2007 11:04 pm

The followspline animator calculates a cubic spline from the support points you give it. No need to reinvent the wheel.
If you want to draw that spline (in order to visualize the way) this is another point, that's not possible.

Namek Kural · Post by **Namek Kural** » Wed Nov 07, 2007 3:08 pm

Thanks! Don't forget to answer the first post! Bye

thomascheah · Post by **thomascheah** » Tue Nov 13, 2007 5:29 am

I am sure if Irrlicht provide include certain methods like CatMullRom in DirectX SDK, that will solve the above once and for all, both for drawing curvee and animating through curve path.

hybrid · Post by **hybrid** » Tue Nov 13, 2007 8:49 am

No, for drawing splines we will need to have some additional primitives. Calculating the splines on our own will only be necessary for the software drivers, because hardware drivers have built-in support.

trnrez · Post by **trnrez** » Fri Jan 16, 2009 10:28 pm

Has support for drawing splines been added?

hybrid · Post by **hybrid** » Fri Jan 16, 2009 11:21 pm

No, nothing in that direction has happened.

Darktib · Post by **Darktib** » Sat Jan 17, 2009 1:45 pm

if you want to draw splines, you'll have to implement it yourself.

It is not very hard, here is a link :
http://www.gamedev.net/reference/progra ... /page2.asp

It explains you how to use splines in 2d, but the adaptation in 3d is not very hard.

Note that there is a mistake in the parametric equations:

Code: Select all

x = At^3 + Bt^2 + Ct + D
y = Et^3 + Ft^3 + Gt + H

should be

Code: Select all

x = At^3 + Bt^2 + Ct + D
y = Et^3 + Ft^2 + Gt + H