LiAR isn't a raytracer

Christer Ericson, author of Real-Time Collision Detection has written a little article on Plücker coordinates and why they are considered harmful. It’s great. I never really understood what all the fuss was about, as I could do the Plücker coord tricks as easily with basic 3D linear algebra and its triple product. So, I’m glad […]

As of 28 June 2007, Sourceforge will decommission the SVN access URLs starting with https://svn.sourceforge.net/svnroot/. They are replaced by URLs with the project names in front. For LiAR, this looks like https://liar.svn.sourceforge.net/svnroot/. The new URL scheme is part of an upgrade of the Subversion access method to improve its stability. If your local working copy […]

We’ve successfully moved the LiAR home page to http://liar.bramz.net. This should allow us to upload bigger renders, and get better search engine coverage. The old URLs starting with http://liar.sourceforge.net should redirect traffic to the new site so that no links get broken. Share and Enjoy!

If you’re planning to install Visual Studio 2005 Service Pack 1, keep this in mind: Make sure you have at least three gigs of free space on your C: drive. To be on the safe side, make it four gigs. Windows Update tries to shove this up your arse as a security update, but don’t […]

While debugging another segmentation fault on linux, I was trying to run LiAR in gdb (actually KDbg). The program crashed somewhere in an allocator, but the reason why was almost impossible to see. The debugging experience was crippled because distutils compiles with full optimization -O3 by default, at least my linux box. If I was […]

When I tried to run a first render in linux, I got a segmentation fault in the photon mapper because there were no lights. Of course, this shouldn’t cause a crash (fixed by now), but why were there no lights? I was pretty sure I defined one, and a quick investigation of the scene graph […]

The description of LiAR says: “‘LiAR isn’t a raytracer’ is an open source, cross platform, object-oriented and extendable ray tracer written in C++ and Python by Bram de Greve”. However, that’s not entirely true since currently, LiAR only runs on the Windows platform. It’s time to live up to the promise. To be honnest, I’ve […]

I’ve added clip mapping (*) to LiAR, which is some sort of alpha channel for surfaces. It can be used to create holes in a surface using a texture. The texture is compared to a threshold to determine where the surface should be removed, so that rays can travel undisturbed through the removed parts. This […]

I’m trying to use the subdivision surfaces I’ve implemented to get a smoother surface for car i’m rendering for PHD Motorsports. The original model has UV coordinates that need to be interpolated as well. As each triangle is split in four, each edge is split two. I’ve been using the naive assumption that for the […]