<div>Hi Rob, Lars,</div>
<div> </div>
<div>Thanks for all your help and suggestions. I'll be giving them a try tomorrow with a fresh pair of eyes. I'll let you know how I get on.</div>
<div> </div>
<div>Regards,</div>
<div> </div>
<div>Paul.<br><br></div>
<div class="gmail_quote">On Wed, May 20, 2009 at 2:09 PM, Rob Guglielmetti <span dir="ltr"><<a href="mailto:rpg@rumblestrip.org">rpg@rumblestrip.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<div class="im">On May 19, 2009, at 8:09 PM, Paul Chilton wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">In the .rif file, I'm creating the mkillum function which I've used the tutorial example is; mkillum= -av 18 18 18 -ab 0 . I then go into the .rad file to find the properties and geometry of the skylight and then copy and paste those values and descriptions separately into a new .rad file and save it as window.rad. In the .rif file I then refer to this window.rad file by specifying illum= window.rad. My interpretation of this procedure is that rather than the ambient being the generator of light into the space it is now the window itself which is the light source.<br>
</blockquote><br></div>Hi Paul,<br><br>So you're on your way. Lars has explained that mkillum will do the "bringing of the direct component closer to your scene" as I suggested. A couple of other pointers:<br>
<br>You want to create impostor geometry or define your skylight apertures as illum sources. You do this by adding "illum=" lines to the .rif file. Let's say you have a skylight defined by a skylight.rad file, that describes the polygons that make up the skylight opening; you would remove that reference from the "scene=" line(s) and add an "illum=" line. You are telling rad to take any polygons defined in the illum= files and do a backwards raytrace from those polygons and out into the scene beyond. Generally this is the exterior environment, and as such the rays traced stand a much better chance of hitting the sun. The results of this raytrace operation are saved and applied as a data file to the polygons defining the skylight or aperture and that aperture becomes a light source. I would not worry about an -av value for your mkillum= line, but I would definitely increase the -ab value to 2 or 3, and -ad 512.<br>
<br>You should not do anything to the .rad files from there. rad is great; if you tell rad (via the illum= line(s)) which surfaces should be precalculated as light sources, rad will manage the creation of these secondary light sources as they are called and create its own separate rad files that substitute the precalculated illums for the calculations and/or renderings. Definitely look at the rad manual page for more info on this...<br>
<font color="#888888"><br>- Rob Guglielmetti</font>
<div>
<div></div>
<div class="h5"><br><br>_______________________________________________<br>Radiance-general mailing list<br><a href="mailto:Radiance-general@radiance-online.org" target="_blank">Radiance-general@radiance-online.org</a><br>
<a href="http://www.radiance-online.org/mailman/listinfo/radiance-general" target="_blank">http://www.radiance-online.org/mailman/listinfo/radiance-general</a><br></div></div></blockquote></div><br><br clear="all">
<div></div><br>-- <br>Paul Chilton<br><br>Renewable Energy Engineer<br><br>[m] 0400 306 791 | [e] <a href="mailto:p.chilton@gmail.com">p.chilton@gmail.com</a><br>