CG:Skeelogy

Featured in NUS Career Centre Guide 2012

Skeel — Thu, 29 Mar 2012 07:47:40 +0000

I am featured in the NUS Career Centre Guide 2012 as a prominent alumni from the School of Computing working in the visual effects industry. Go check it out!

Showreel 2011

Skeel — Tue, 18 Oct 2011 22:56:36 +0000

A compilation of the shots from the various movies that I have worked on from 2009-2011.

John Carter (2012) - FX
Sherlock Holmes (2009) - FX / Lighting
Captain America: The First Avenger (2011) - Lighting
Iron Man 2 (2010) - Pipeline [no shots available]
Scott Pilgrim vs. The World (2010) - Camera/object track
The Sorcerer’s Apprentice (2010) - Camera/object track
Kick-Ass (2010) - Camera/object track
Green Zone (2010) - Camera/object track
Paul (2011) - Camera track

Shape Matching in Houdini

Skeel — Mon, 03 Oct 2011 02:56:01 +0000

Implemented a shape matching algorithm in Houdini using VOP. This is based on “Meshless Deformation Based On Shape Matching” (Müller et al., 2005).

Given a set of non-connected point cloud, the algorithm fits the original geometry into it in the best way possible.

The most involved part in the algorithm is finding the square root of a symmetric matrix. It’s interesting to know that Houdini has a VOP that returns the eigenvalues of a matrix, but not their corresponding eigenvectors The eigenvalues and eigenvectors would have been useful in transforming the matrix into a diagonal matrix in another basis and thus making the square root easy to calculate. Used the Denman-Beaver iteration in the end instead and it seems to work pretty well.

This is just the first part - shape matching. What’s left to be done is to use this shape-matched geometry as a goal for each vertex for soft body deformations, using the unconditionally stable integration method mentioned in the paper.

Melt SOP using VOP/VEX

Skeel — Mon, 26 Sep 2011 00:08:36 +0000

Created a Melt SOP that allows user to melt an object using a 0-1 slider. Did this in a VOP SOP originally, but coded it in VEX as well

Houdini 11, Mantra Micropolygon Renderer

The basic idea:

1) Move the points down proportionally according to the melt amount.

2) If a point gets below the bounding box, set its Y value to the minimum Y of the bounding box, and spread the point outwards in the XZ plane. This spreading-out motion could be in a radial direction away from the centroid, or along the point’s normal

- For an object with holes, such as a torus, using normals would be a better choice so that melted pool will spread into the holes as well.

- For an object like a cube, spreading radially outwards from the centroid would be a better choice because the normals for each side are facing the same direction, making the spread look stretched at the corners and unnatural

Noise is added to this outward spread to give a bit of variation.

3) Lastly, we need to give the melted pool a thickness, otherwise all the faces will be at the same level and undesired flickering will occur during shading. This is done by moving the points of the pool down proportionally according to how much they are supposed to be below the bounding box. This will cause the object to go below the ground, thus we have to move ALL the points up so that the bottom of the object stays stationary at the same level.

Download sample files (hip, otl, vfl, vex):
http://cg.skeelogy.com/?download=houdini_skeelMelt
(Both VOP and VEX implementations are included)

FX Reel 2011

Skeel — Mon, 05 Sep 2011 02:39:36 +0000

My FX reel which showcases mostly personal Houdini works and some professional work for Sherlock Holmes.

I’ll be updating this reel as more works get done over time.

Skills and experience in FX

Able to create effects/simulations in Houdini, render necessary passes with Renderman (Houdini/Maya), and then composite them together in Nuke to demonstrate their usability
Houdini: Pyro FX, VOP/VEX, rigid body, particles, cloth etc
Maya: fluid, nCloth, soft/rigid body, hair
Able to program simulations of soft/rigid bodies, fluid, anatomical/deformable models, collision detection etc from scratch

Burning Poster

Skeel — Tue, 02 Aug 2011 11:50:46 +0000

Simulated a burning poster in Houdini using Pyro FX.

Used a VOP SOP for the spreading of the flame front, together with a SOP solver. A cloth solver is used simultaneously for the dropping motion.

Flickering/lighting on the poster was done by reading in point clouds generated from the fire volume and using that to add contributions to the poster’s lighting in a custom shader.

Credits to Peter Quint for his excellent SOP Solver tutorials in Vimeo.

Houdini 10, Mantra Micropolygon Renderer, Nuke

Credits in Captain America: The First Avenger

Skeel — Fri, 29 Jul 2011 15:41:56 +0000

Got my credits for Captain America: The First Avenger as a Technical Director

Burning Torch

Skeel — Wed, 20 Jul 2011 12:09:28 +0000

Torch drops onto fuel on the ground and sets it on fire

Houdini 10, Mantra Micropolygon Renderer, Nuke

Pyroclastic Smoke Test

Skeel — Tue, 19 Jul 2011 12:46:51 +0000

A test on getting some pyroclastic smoke in Houdini.

Houdini 10, Mantra Micropolygon Renderer

Swarm Movement Test

Skeel — Tue, 19 Jul 2011 12:28:14 +0000

Swarm movement test with the help of a fluid sim

Houdini 10, Mantra Micropolygon Render, Retimed in After Effects

Fire Simulation Test

Skeel — Sat, 09 Jul 2011 12:51:57 +0000

Fire simulation done using the smoke solver DOP. Looking more like a stylized fire rather than a realistic one at the moment.

Houdini 10, Mantra Micropolygon Renderer

Also increased the voxel resolution of the fire simulation using the Gas Up Res DOP to see how much detail can be squeezed out of it:

Panorama - Taiwan 2011 - Lomo Spinner 360

Skeel — Tue, 12 Apr 2011 00:31:29 +0000

Took some panorama photos using the Lomo Spinner 360 during my Taiwan 2011 trip. Loving the perforations in the photos.

Lomo Spinner 360
Kodak Gold 400, Agfa Vista 400

Panorama - Taiwan 2011 - Photaf

Skeel — Mon, 11 Apr 2011 22:36:54 +0000

Took some panorama photos using my HTC Desire during my Taiwan 2011 trip.

HTC Desire
Photaf

Credits in Scott Pilgrim vs. the World

Skeel — Sat, 13 Nov 2010 15:49:50 +0000

Got my credits in Scott Pilgrim vs. the World as a Camera Matchmover

Multiple/Long Exposures - Marina Bay Singapore

Skeel — Sun, 31 Oct 2010 00:46:44 +0000

Tried out some multiple exposure shots and long exposure shots at Marina Bay Singapore.

Gakken panorama pinhole (wide shots)
Holga 135BC (others)
Fujifilm Provia 100f, cross-processed

Panorama - Gakken

Skeel — Sun, 31 Oct 2010 00:09:59 +0000

Took some panorama photos at Marina Square Singapore using a Gakken pinhole camera (a plastic camera assembled together from given parts). It’s approximately 30 minutes of exposure for each shot because these are night shots taken with a pinhole camera.

Gakken pinhole camera
Fujifilm Provia 100f, cross-processed

Macro - Dual Lens Reverse

Skeel — Fri, 22 Oct 2010 23:55:09 +0000

Bought a reverse ring adapter to attach a reversed short lens onto a long lens for some macro shots. The amount of magnification depends on the ratio between the short and long lenses used. This offers really high magnification when the right lenses are used.

Canon EOS 60D
Canon EF 50mm f/1.8 II (reversed)
Canon EF 100mm f/2.8 USM
Reverse ring adapter

Macro - Extension Tube

Skeel — Fri, 22 Oct 2010 23:46:03 +0000

Bought a cheap extension tube recently and attached my lens onto it to take some macro photos. Loving the extremely shallow depth of field using this technique.

Canon EOS 60D
Canon EF 50mm f/1.8 II
Extension tube (approx 2.5″)

HDR - Kampong Buangkok

Skeel — Sat, 16 Oct 2010 01:57:08 +0000

Took some exposure-bracketed shots at Kampong Buangkok (the last village in Singapore), and combined them into tone-mapped HDR photos.

Canon EOS 60D
Tamron SP AF 17-50mm f/2.8 XR Di II LD IF
3 exposures combined in Photomatix

HDR - Labrador Beach

Skeel — Fri, 24 Sep 2010 22:05:10 +0000

Took some exposure-bracketed shots at Labrador Beach Singapore, and combined them into tone-mapped HDR photos.

Canon EOS 450D
Tamron SP AF 17-50mm f/2.8 XR Di II LD IF
3 exposures combined in Photomatix