Archive for 2006

loop subdivision surfaces

Tuesday, December 12th, 2006 by Bramz

I’ve implemented subdivision surfaces for the TriangleMesh using the Loop’s scheme. Triangles are split in four, and the vertices are weighted using masks to produce a smoother surface. This process is repeated a few times, indicated by the subdivision level. The implementation also supports the concept of creases. If an edge of the mesh has […]

FZR in Uffizi (and thin dielectrics)

Saturday, December 2nd, 2006 by Bramz

I’ve reproduced the older FZR render using the Ashikhmin & Shirley BSDF and the Uffizi Gallery light probe. For the glass of the windows and the head lights, I’ve implemented a new material called ThinDielectric that acts as a thin (but not very) pane of glass. Given an inner refraction index and transparency factor for […]

caustics in the cornell box

Wednesday, November 15th, 2006 by Bramz

It’s been more than a month since last update, so it’s time for a status report. I’ve been further playing with photon mapping and some nice shaders. The main additions to the photon mapper itself are the (ir)radiance caching when using the final gather step, and the caustics map. The former was – I believe […]

photon mapping with the cornell box

Tuesday, October 10th, 2006 by Bramz

Summer is over (already 20 days since September 21), and as promised, we’re back with some more LiAR stuff =) I’ve been busy with a few things, the main one being the photon mapper. It’s not completed yet. Currently we only have a global photon map and a gather step with a full radiance estimate. […]

summer break …

Tuesday, June 20th, 2006 by Bramz

Hi all, It’s been a while since the last update. We can assure you that LiAR isn’t dead, but unfortunately we have been through some busy months, and some more are coming up, which puts everything on a hold. So there probably won’t be many updates in the next couple of months either. See you […]

image based lighting

Wednesday, April 26th, 2006 by Bramz

My first render using an environment map as skylight … Using the technique described in Infinite Area Light Source with Importance Sampling by Pharr and Humphreys, it’s implemented in a breeze … (thanks Thomas, for pointing out that article =) (Light probe: Grace Cathedral by Paul Debevec)

Fixing transformations and local geometry

Thursday, April 20th, 2006 by Bramz

Today, I noticed there was something seriously wrong with the way local differential geometry was treated by transformation objects. Basically, rendering goes like this: find intersection, find geometry of intersection, get shader at intersection, shade using the geometry. However, currently, if the object being intersected is a transformed one (by scenery::Transformation), all local geometry (3D […]

shaders or BSDFs?

Tuesday, April 18th, 2006 by Bramz

I’m in a bit of a design dilemma right now … Currently, materials are implemented as shaders. This is similar to the RenderMan Interface. Each material is a piece of code that gets executed when the ray tracer hits the surface, and yields the outgoing radiance (the colour to be rendered). That’s great, we have […]

cornell box (direct lighting only)

Monday, April 17th, 2006 by Bramz

Today, I’ve being translating the ever-famous Cornell box to a python module. Of course, I also had to make some render, so here it is. Since I still only have direct lighting (ok ok, I really need to fix that =), the result is not so terrific. But there’s at least soft shadows ;) The […]

area lights

Sunday, April 16th, 2006 by Bramz

Today, I’ve been playing a bit with area lights … They are implemented as a scene object scenery.LightArea that takes another scene object as light surface. I’m not entirely happy with it, but here’s some tests … The first one is the good ol’ red sphere with a spherical area light. The entire scene is […]