Everything is a Remix

http://vimeo.com/25380454

Side Effects Cookoff!

http://www.sidefx.com/cookoff/

I'm so looking forward to this! Hopefully, I will be able to get something out in time. It has to be food related, however my idea is not exactly food - mixing milk into tea. *yeah everyone tells me it's not food* but you know what, even if it doesn't qualify for the competition, I'm still going to try to get something going. It's always possible to learn new techniques from just trying out new ideas.

Already have some reference footage of tea being made ;-) Let's go!

GW

Houdini: Foam Pass for level set fluids

I've been using Exotic Matter's Naiad for water simulations, and apart from the main simulations, other layers are included, such as foam particles floating on the surface, as well as particles ejected away from the surface to simulate spray.

This experiment is an attempt at creating foam off a Houdini Level Set Fluid simulation (Note: Naiad uses FLIP fluids.)

Emission is basically scattered points on a  mesh that was converted from the fluid's main level set ("surface" volume: with a convert sop you can get a mesh). Two parameters are used to control emission regions; curvature (measure SOP) and velocity (lookup into velocity volumes).

These points are then used as for emission in POPs; this particle layer is relatively fast to simulate because it's all pops! Inside pops, there is a fake "advection" stage where the particles sample the velocity volumes from the base simulation, and uses that to move each particle to its new position.

This however will result in particles moving into positions below the surface, or a bit too high above the surface. Tests indicate this can be improved by a high resolution level set, but we all know how expensive those are ;-)

Instead, a VOP POP was created to move the points based on the gradient of the base simulation's distance field, and points are moved accordingly to whether they are negative or positive (i.e. negative distances moved towards the surface following the gradient vector; positive distance are again moved, but against a negative distance vector).

I have no idea about those spots that hang on the ceiling - there is a cull pass that removes particles if they are a set distance away from the distance field. Since those particles are hanging there, I'm assuming there are remnants of the level set that do not have velocities affecting them and not dissipated.

That's it for this experiment, maybe I'll look into it another day.

GW

Houdini: Arrow system using Quaternions

Got inspired the last few days to design an "Arrow" system and finally took Friday evening and Saturday morning to figure out a good way to create a system that allows stuck particles (arrows) to change their orientation based on the underlying deforming geometry.

The main concept is getting an origin frame of reference (in this case, it's the primitive normal of the collided polygon that the particle hit, as well as the vector of the first two vertices. These will give a reference frame.), as well as a constantly updating frame of reference (the prim normal and vector again, from the deforming primitive).

Originally, I had used the Align VOP to perform this calculation, however, the align vop simply returns a transform from one vector to another vector via the shortest path. In this case, it is basically a rotation with an axis that is the cross product of the two vectors. What we want is a proper rotation, so I used the look at vop to generate rotation matrices from the two frames of references.

Next, these were converted to Quaternions, and then I used the SLERP function (Spherical Linear Interp VOP) to obtain yet another quaternion that blends the original frame orientation to the final deformed frame.

The issue I encountered was that the SLERP function returns the initial orientation quaternion when both the initial and target orientations are the same - this is obviously the case during the collision frame; both reference and initial orientation are exactly the same.

This, we do not want; as during the collision frame, I want my arrow's normal vector to be operated on by a Quaternion of xyzw = {0,0,0,1}, not the quaternion for the initial frame. Hence, by subtracting the initial frame's quaternion from both the initial frame as well as the target frame (this is done by doing a quaternion multiplication of the conjugate of the initial frame's quaternion against both initial and target quaternions before putting them into the SLERP).

This seemed to work, from the examples above. :)

Woo! Slowly attacking quaternions. And Houdini just makes it so simple.

Other issues I encountered is during rendering: proper motion blur for the arrows. With a stuck particle, the "v" velocity vector is actually locked in place whilst the particle is with the pstate of 16, hence during renders, this is uber incorrect.

Initial tests using to Attribute Transfer velocity vector (calculated using a Trail SOP) did not work out as it was very inconsistent. What I did then, was to do a look up into the geometry (the collision POP stores the posprim attribute, allowing us to find out which primitive to query), and allow the hit arrow to take the velocity of the underlying geometry.

GW

Saxophone Log: May 2011

Here's another saxophone log from this month. I'm playing from a play along book called "Dig It!" for Saxophone.

What's nice about this is that just one book caters for Alto, Tenor and Soprano as well! The Tenor and Soprano scores are similar, just that the soprano will need to be played one octave below the score. In addition, there are multiple parts for the different saxes, to be played together e.g. alto + 2 tenors. Good stuff!

Side Effects Software: Why use Houdini?

And more question such as:
How many companies have a new daily build accessible from their website, containing bug fixes and feature improvements?
Where can you meet the developers in person and talk to them?
How often do representatives visit you in person?

Well SESI does all that, and more. A few weeks ago, I put up the robotic servo arm controlled by Houdini. It's just a proof of concept that went overkill, but seemed to generate a fair bit of interest, so much that the code and concept may be used for other projects.

Fast forward to last night, it seems like I had failed to test for keyframed animation support, and I fixed the otl right up. The developers at SESI took it to actually rebuild my entire digital asset from the ground up, pythonized, so while it looks the same on the outside, the guts are totally revamped.

http://www.youtube.com/watch?v=TImyQ7VnS_M

http://forums.odforce.net/index.php?/topic/12916-houdini-arduino-robotic-claw/

Next project I'm working on will involve an ADXL335 accelerometer, what will I use with it? As always, these are proof of concepts I hope to learn from to build on for bigger projects :)

Saxophone Log!

To prove that I have no life, here's me on my monthly saxophone log.

Houdini + Arduino + Robotic Claw

Ok so I've been amiss from updating this blog. I am still snapping photos left right and center, but I've not been putting them up here (mainly on facebook). This is because I'd planned to have dedicated website for my photography, and a photography blog as well. The website is up, but... the content is not ready :D Will be coming probably in June, after I finish my current project and get some free time.

In the mean time, I am very busy at work (crunch time now, for the next 6 weeks at least), and when I'm not at work I'm working on other stuff, some of it which is houdini related. Like today's post!

So I've been working on Arduino for several months now, just on and off when I get a free moment, to keep busy. (Else my mind wanders). I think microprocessors are awesome, but back in the day when we had to use massive programmers and UV light to wipe the memory, it was not as accessible as the Arduino, which only requires a USB port to provide power, transfer programs from the pc to the microprocessor and do other cool stuff, like what I did above.

Source code and the HDA can be found on odforce.

I'm slowly getting back into doing Houdini as well (where do I find the time for this, when I'm learning how to draw, learning the sax, doing my photography, houdini, work and other stuff?!) - have been inspired by lots of work lately, and want to create some of them by my own hand :3

Looks like someone's laptop needs a ram upgrade. DDR3 anyone?

GW

More camera related nonsense - Nikon P7000 vs Canon G12

Basically, Nikon makes crappy handling P&Ses!

Ok to be fair, I'm mainly comparing Nikon and Canon, Sony's handling is even worse off for me.

So on my way back today, I decided to ponder if a P&S would work for me instead, and decided again to drop by Jessops to check out the Panasonic LX5. Seems like it's a very popular camera, as even the display model was sold :-/

Nevermind, I'll check out Nikon's top of the range P&S instead. Costing about an entry level DSLR, (a used D200 is cheaper), it feels really nice, and I was going, "Oh wow, look at all these controls! Gotta be a dream to shoot with!" Sadly, it took me a fair bit of fiddling to actually figure out basic stuff like trying to change the ISO or white balance. Still, it feels very good and well proportioned in my paws.

Tried a few other Nikon P&Ses but I'll not bore you to death further.

Popped over to the Canon section, and lo and behold, the luscious G12 was there. Immediately, I saw how easy it was to manage the camera - ISO was on it's own dial, even with Auto ISO - I may actually prefer having a dedicated ISO dial on my dslr - and EV comp was it's own button, and another dial for easy PASM stuff. I thought it was very well designed, and the handling was superb. Menus were also easy to get into. Folding screen + optical viewfinder? Big big pluses.

Gotta try the LX5, however if it's menu layout is like the TZ8 - I'd say I'd pick either the G12 or LX5, as they are cameras for different purposes - especially the LX5 with the low zoom range and fast lens. P7000? Another top of the line P&S I will probably not care about.

GW

Checked out a Nikon D5000 today

So I went past the Jessops along New Oxford Street (in London, UK for newer readers) seemingly by accident today, and decided to pop in to give the D5000 and D3100 a try after dismissing them the last time.

(Side Note: At the moment, I've more or less disqualified the GF1 as a choice, mainly due to the insane distortion of the normal zoom and battery life. Maybe down the road when I have loads of disposable £££ I may get it, however right now, I want something I know I will use.)

As luck would have it, the D3100 was not on the shelves, sold away perhaps? Only had the D5000 to try. As mentioned in a previous post, I put the D5k and D3.1k at a firm no just by virtue of their lack of a top LCD screen. A screen I use very very often on my D200/300 for settings.

First off, the AF on the D5000 was bloody bloody slow. And no AF points showed up. A quick tour of the menu indicated the auto area AF. Switching over to single point AF resolved any speed issues. I've owned the 18-55VR in the past, and am quite familiar with its focusing speeds. I wonder if this auto-area AF is similar to the close priority dynamic AF on the D200 - the AF was so much faster on the D200 in similar light. But who knows. I am fine with the single point and dynamic AF on the D5000 + 18-55VR, it's definitely not 17-55 AF-S speeds, but snappy enough inside the store.

One big issue concerned me - the seeming inability of the camera to separate the shutter button and auto focus. I was able to set the custom function to allow the AE/AL lock button to be used as Af-on, however, did not find a custom function to disable AF on the shutter release. As with the D90, the AF selector is just waay off from where my thumb rests.

There is a possibility I'm just asking too much from a budget, entry level dslr designed for beginners :) Some plus points include a very nice +/-2 stop bracketing ability. I'm pretty sure even my D300 has a maximum of 1 stop between brackets, though it's possible to do a 9 frame bracket on the D300 vs 3 on the D5000. That's a low priority thing anyways. Tested live view AF - a joke, seriously when compared to the GF1, or even my Lumix FS7. Also, the AF point layout is similar to the D200, plus point there. And there is even the overlaid grid which I really like. Viewfinder is of course, super dim but we're talking about a small dslr with a pentamirror, not pentaprism and 100% view which costs like 3 times more.

Also, the obvious lack of AF motor. In general though, looks promising. I'm just reeling at the idea of missing the usage of the 24/2.8 and 50/1.8 on this baby. However, as memory serves, I've never actually used either of these lenses when out on tour even though I've brought them along so..... perhaps I should just bite the bullet and get the D90.... or D5000 + a 35/1.8DX to satisfy my urge for a fast prime (hahaha 2.8 is fast for prime? lols)

On a crop body, the 35mm is about 52.5mm equivalent field of view, which I am just not a big fan off :-/ Even when I was shooting film, on my Contax G, even though the 45mm/2 Planar produced the most amazing feel, I still preferred a wide normal; hence the 35/2 was the one mostly mounted.

End of the day? I still have no bloody idea. I've still got a week or so to decide. Ah well.

Getting a smaller camera - D90? GF1?

So my D200 has been dead for several months now, and I've just started the hunt for a smaller camera.

Why?

Basically, whilst my D300 is super awesome kickass, for general day to day use, and just basic travel purposes - it's just to damned big and heavy. In addition, it's not inexpensive, and I just don't like swinging around something that expensive everywhere I go. The D200 IS expensive... back in the day.Thankfully I got mine used for a bargain.

So I've made a trip down to Jessops today, twice actually, to check out the cameras on display.

For the Nikon lineup, I tried the D5000, D3100 and D90.
Other cameras I've tried included the Sony NEX series, Olympus PEN, one of the Samsungs and the Panasonic Micro 4/3s.

Nikon side, the D3100 and D5000 were immediately off my shortlist. When I first grabbed the camera, I went... erm... where is my top lcd? Can't change my settings quickly without that! The back LCD is where its all at, but it's just too damned cluttered. Nope.

D90 wise, apart from me nitpicking certain aspects, seemed like a good choice:
- Push button + control dial for ISO, WB, Qual, Drive etc. Very much like the D200.
- Rear screen is awesome
- Good size and weight
- Shares batteries with my D300
- AF system is similar to the D200, so no issues there
- Viewfinder, though I don't have my D300 with me, seems bright enough. Don't need no 100% viewfinder.
- Motor for AF lenses! 
- Relatively quiet shutter. My D200/D300 sounds damned loud in comparison. Could this be due to the slower shutter release time?

Nitpicks:
- The main one: The 4 way rocker which is used to select the AF points during shooting is just not lining up with my right thumb. This has to do with the physically smaller camera. The D200/D300 has the AF selector perfectly where my thumb rests on the back of the camera, not on the D90. It is much lower.
- No dedicated AF-On button. I think the AE lock button can be configured for that, but then how am I supposed to lock exposure? :P

Really minor nitpicks
- Flash sync of 1/200. Bleh.
- Bracketing features weak compared to D200. But I don't bracket much so...
- Uses SD cards (yuck), but can't be helped.
- RGB histogram doesn't show flashing highlights
- The name D90 is just not as inspirational as D200 or even D5000

Olympus:
E-PL1 has so-so autofocus speeds. Really, really did not like the menu layout.
E-P2 - again so-so AF speeds. Controls much better, but menus still weak.

Sony's NEX
Af speeds seem good, and the handling of the camera is surprisingly good. However, the menus seem to expect the user to be a total n00b. Nah. Also, the 16mm lens is an odd choice for their fixed prime. 24mm equiv fov is quite wide and not easy to use as a single lens.

Samsung:
Only tried the Samsung NX100, not a fan of the interface. Controls of camera body were quite sparse too. Eh...nah.

Panasonic:
Well last to be mentioned. Because I really enjoyed the camera. I tried the G2 and GF1, and thoroughly enjoyed the GF1. The on screen display has symbols indicating e.g when in manual mode, to push in the rear dial to switch between controlling aperture and shutter speeds. ISO has a dedicated button, as with AF and some other settings that I forget.

AF speeds are fast and responsive, and I enjoyed the AF tracking mode. I mean, look. I didn't even read the manual, it just worked thanks to the blinking icons!

Body is also very well built, feels like a nice expensive piece of kit, whereas the D90 really feels plasticky.

20mm/1.7 is an amazing lens. Just for that lens alone - giving a 40mm QL17 equivalent FOV - is a tempting idea.

At the moment I'm not sure if I should get either, get a used D200, or just don't do anything. The D90 will allow use of all my lenses and flashes, and apart from the SD cards, a straight fit into my system. And it can be the lightweight counterpart I could use on a day to day basis.

The Panasonic OTOH is just so damned tiny. Even with the zoom lens on it's minuscule, even compared to say, D300 + 24/2.8D.

Ah well. I'll see what happens.

Traffic Light Tree

Was at Canary Wharf this weekend, and shot this Traffic Light Tree sculpture :D

My Son Is Gay

No, obviously I do not have a son (or daughter) but this blog post I saw really makes me ask myself if people actually understand certain basic aspects of Sex, Gender and Sexuality.

Sex: What reproductive organs you are born with
Gender: Whether you identify yourself as male, female or other
Sexuality: Whether you are straight, or homosexual, or the whole gamut of sexuality.

If wearing female clothes makes one change their sexuality, will wearing a werewolf costume make me a wolf? Gods, people. I really love the Ninja comment :D

GW

Eagle Heights in the rain

Went to Eagle Heights today, but got hit by showers in the morning.

 Harold the Griffon Vulture demonstrating his 8 foot wingspan. He's being weighed.

 Due to the rain, the usual flying demonstrations were held indoors. 

Here, a White Tailed Eagle lands beside my friend.

 I didn't even know I shot this!

 Tawny Eagle. Not my usual style to include man made stuff, but thought it was interesting.

 A view of the road up to eagle heights lined with the trees in full autumn colours.

 Unidentified falcon nomming on just caught Partridge.

On the way back, Swanley rail was experiencing engineering works, shot this whilst waiting for the rail replacement buses.

Portobello Markets and Trellick Tower

Decided to visit the Trellick Tower via Portobello Road. I deftly avoided all the classic camera stalls. The shots from yesterday were useful in color grading than anything else.

Slowly getting the hang of Bibble 5

It's been several months since moving on to Bibble 5, and I'm slowly getting the feel of the package. Here's one of my latest attempts from a visit to the ZSL today. I call it, "bending over".

Bushy Park Deer Rut

I think I may be shooting it a little late in October since I was so busy last month.

Maybe next week I'll be able to get some fighting shots.

Brutalist Architecture : Robin Hood Gardens

Was introduced to Robin Hood Gardens as a possible photography subject, and surprise! It's an example of brutalist architecture. A kind of architectural subject that I have a love/hate relationship with.

Here's what I got today:

The whites look a tad grey in my browser :-/ Darned color management.

GW

Whipsnade Zoo in the rain

Visited Whipsnade Zoo today with a fellow photog. Was hoping for good weather (go, power of positive thinking!) but we were inundated with bucket loads of rain.

I decided to risk it and just wear my cool weather gear, and was quite damp at the end of the day. I shoulda just brought out my full wet weather kit :-/

Anyways, here's a few of my favourites:

The sad old king.

One of the cheetah cubs at play. They were born in late may.

Awww..... Contrast is very low thanks to shooting through wet glass >.<

Don't you wanna hug 'em?

A pack of 8 wolves, 2nd in number to Bayerischer Wald in Germany. The inclement weather seems to have them very active. Love those furballs.

I title this "Not talking to you"

On the way home.

And a bunch of fluff balls :)

GW

Its wet...

Inside Leicester Square Tube. Just a random shot with the camera on a pedestal.

Heading home in the rain.