Goblin, version 5

These two images show one of our goblins superimposed on a photograph from Goblin Valley. The geometry of the goblin was generated from a block of voxels using a spheroidal weathering algorithm. Original photograph in the background used courtesy of Leping Zha, www.lepingzha.com. (Algorithm: Matthew Beardall, Texture and Animation: Cory Rheimschussel).

Goblin, version 4

 

Our goblins have come a long way since January. We use the same basic erosion simulation, but we've got better back-end processing. The back-end processing smooths the surface, otherwise we get lego-like shapes (as seen below). In this version, we are using marching cubes to extract the 0.5 isosurface (0.5 measures the degree of decimation of the volume). We do some more smoothing in Maya and then apply two textures. One texture for the top and one for the bottom. Cory Rheimschussel did all Maya magic and these two textures. Darius Ouderkirk implemented marching cubes.

Natural Phenomena Workshop 2007

The 2007 Eurographics Workshop on Natural Phenomena will be held on September 4 2007 in Prague as part of Eurographics 2007. I was walking around SIGGRAPH last summer thinking to myself "there should really be a workshop on natural phenomena, I think I'll put one together" Then I walked by the Eurographics booth and saw the proceedings from the 2005 workshop for sale by their booth. I immediately bought the proceedings and thought to myself "that was a lot easier than organizing a workshop"

Details: EGWNP 2007

Controlling a Canon PowerShot Camera using PSRemote under Vista

We have a long-running project in the lab in which we are capturing images of mountainous terrain and recording the time and weather in which the image was captured. To date, we have a collection of about 1,500 images paired with time and weather information. We use a Canon PowerShot A620 to collect the images and we use PSRemote by Breeze Systems to script the shots.

On a whim, I decided to install Vista on the machine that takes the pictures. That was a bad idea in the end because Canon has no plans to support Vista with the drivers needed to run PSRemote.

So I installed Virtual PC from Microsoft, put a clean copy of XP on the virual PC and plugged in my camera. Turns out that Virtual PC doesn't support USB devices.

So I grabbed a copy of Virtual Box and repeated the process. Virtual box does support USB connections, but I needed to add Canon's USB explicitly to the USB pass-through filter. That code is 04a9 (courtesy of www.linux-usb.org).

After downloading and installing everything on the Virtual Box, we were back in business and here's an image that was captured last night.

Cubic Goblin

 

The latest and greatest goblin is extremely symmetric and has a nice cube shaped top. The significance of this image is that it shows the results of differential erosion with a hard layer on top and a soft layer on bottom.

We are working on two main issues now. First, getting the results to look less symmetric. Second, exporting the shape to Maya in a relatively smooth fashion for final rendering.

(Credits: Pretty much everyone in the Sandstone Terrain Feature Capstone class for Winter 2007)

Goblin Skin Textures

 

A test render of a Goblin highlighting a skin surface texture by Cory Reimschussel. The small surface features are bump mapped and the colors are intended to match the color of a real Goblin. The geometry is the same geometry generated by Darius Ouderkirk using Matthew Beardall's erosion algorithm. The geometry has two problems. First, there's a slew of infinitely small fins between some faces and it looks like it is made from Lego brand stackable building blocks. The texture isn't too bad and we are working on the geometry as well as the erosion algorithm.

Field Trip Report

The CS Department has posted a report on our recent field trip to Goblin Valley.

I was pleasantly surprised at the value of the field trip. I originally planned it because it might be useful but it would definitely be fun. It turned out to be fun (as expected) but also was more useful than many of the capstone class discussions we'd had prior to the field trip.

Unfortunately, the BYU Rental Fleet Safari vans have a low ceiling which meant I had to dip my head slightly for 6 hours while I drove back and forth between Goblin Valley. This left me with an excruciatingly painful headache after I got home. We'll have to solve that problem next time by renting an SUV from the fleet.