How to write a Bevel Effect in HLSL?

Question

Hi,
 
I wonder if anyone's got some smart ideas (or links with information) about how to write a BevelEffect in HLSL (WPF 3.5 SP1), similar to the old BevelBitmapEffect in WPF.

I know how to create a custom effect, but I have no idea about to write the HLSL code in order to get the bevel "look" for any type of UIElement, e.g. Rectangle, Ellipse, Polyline, Image, etc.

I wonder why a hardware rendered bevel effect isn't provided when there is a replacement for the old drop shadow bitmap effect.

Answer 1

you can write a bumpmap shader and then use a rectangle to achive the bevel effect :) this is slightly harder that just using bevel sader that does only beveling, but its much Much more powerful..  just think what can be done with bumpmapping in games. then thounk of your element as a flat polygon facing towards you.. the possibilites are mindblowing :)

here are a few hlsl pages to get the juices flowing:)

http://www.neatware.com/lbstudio/web/hlsl.html
http://eldeann7.chez-alice.fr/HLSL_bump/index.htm
http://www.neatware.com/lbstudio/web/hlsl.html

just remember, there arent any vertex shaders in wpf and all the normals are facing towards you:) its a steep learning curve but people will be able to make som ecrazy looking apps with pixelshaders..