Light beams in Real 3D v2

In this text I hope to explain how this method works, I hope it makes sense!!!


The theory is to use scope mapping to transform a fog into a matt glass along
the length of a cone extending out from a light source.

The fog has local scope mapping which is most concentrated at the light point
and fades out as the cone stretches away from it. As it fades out the clear
glass takes over and it just seems like the beam has lost it's strength.

To improve the fade I have copied the fog and given it the same properties as
the clear glass and faded that into the fog.

The fog has 100% turbidity and 1% turbid sat. whereas the glass has 100%
turbid sat. and 0% turbidity, this also helps the fade. If you don't want such
as smooth fade then simply remove the Clear2 mapping from the BEAM level and
it will stay solid almost to the end.

Notes.

Material Sampling in the render settings needs to be at least 1. Increasing it
won't improve matters unless you put more transparent stuff inside the beams.

If you are using soft shadows then due to a bug then light sources have to be
inside the fog cutcone or the beam will start to look speckled. Things will
start to go very wrong if you need to use more than one light plane/line.

The beams don't cast shadows, they shouldn't anyway....

The beams can cross as much as you like, just turn up the recursion in the
render settings once for each new cross.

The environment colour must be the same as the background or the effect will
be ruined, unless of course the beam will never be seen against just the
background colour.

Don't make the beams not-reflected or you won't be able to see through them!

Er, that's about it really.... Oh yeah.. They render darn quick...


Andy Jones

Real 3D v2 Beta Tester,
Moderator, Real_3D fidonet electronic mail echo.

Pixel Perfect Computer Graphics
27a Tremaine Road
Anerley
London SE20 7UA
ENGLAND

Tel. +44 081 676 8709

Email 2:253/516.1@fidonet