Like all effects artists I’m always on the lookout for good reference. One of the hardest things to find is high speed video clips. Well today at work someone pointed me to a fantastic site for high speed, royalty-free footage: Lucid Movement.
Particle kill field for Maya
by Mike Rhone
I’ve been using Houdini for the last few months and I realized that it’s been a while since I’ve posted a good trick for Maya particles, so here is a hack I’ve had in the toolbelt for a while. I call this the Maya kill field.
This technique works with both nParticles and regular oldschool particles. In this example I’m using basic emitter and nParticles and have turned on the nucleus gravity for the system. I press play and I get a simple system like this:
Maya doesn’t have any such thing as a ‘killField’, so were are going to hack one using a uniform field node. Select the particles, then create the uniform field. Rename the uniform to killField. Set these settings:
Magnitude = 0.001
Attenuation = 0.0
Direction = 0.0, -1.0, 0.0
Volume shape = cube
When you have the particle selected and you create a field in Maya, the field is automatically connected to the particles. Now that the uniform field is created, scale it up in the scene so it is underneath where the particles are falling as I’ve done here:
In the particle attibute editor, change the lifespan mode to lifespanPP.
A bit of back story. When you connect fields to a particle system in Maya, a hidden particle attribute is created called inputForce. Every field that gets attached to a particle system creates one of these attributes. Because this is the only field in this scene, this attribute is called inputForce. If you already have other fields in your scene this field may be inputForce, inputForce etc.
Now that we understand that, lets create a particle expression to tell Maya what to do with this killField. Open the attribute editor for the particle system, right click on lifespanPP in the per particle (Array) attributes section and choose ‘Creation expression’. Now add this expression:
if (mag(inputForce) >= 0.001)
lifespanPP = 0.0;
Corrected – Special thanks to Matt Whelan
Click Create. Now copy that expression (CTRL+C) , then click on the ‘Runtime before dynamics’ radio box. Paste the expression in there as well. Click Create.
That should do it! Press play and you should see the particles disappear as soon as they enter the ‘killField’. Now if you want to have a setup that kills particles that are outside of the killField volume, turn volume exclusion ON on the killField.A bonus to this method is that because we are doing this via particle expressions and fields it is many magnitudes faster than using a collision event to kill particles.
Now I did say this was a hack. One problem with this method is that the particle is killed the frame after it enters the kill field. This is because the particle needs to be in the kill field before it can affect it. Scale the field up or down as needed. For the kill field to work it has to have a very small amount of affect on the particles. I have found a uniform magnitude of 0.001 is usually so negligible it won’t be noticed.
Feel free to leave comments, questions or suggestions…!
This tutorial is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.
polyCube -w 1 -h 1 -d 1 -sx 1 -sy 1 -sz 1 -ax 0 1 0 -cuv 4 -ch 1;
If you copy and paste that line into the Maya script editor and press enter on the number pad you will create a poly cube. Saying all this, I would hold off on MEL and Python for now though, just focus on particles and particle expressions. You can dabble in scripting languages later.
I received an email a short while ago from an aspiring effects artist named Bojan, and I thought it would make a good post here to anyone that wanted a big more info about being an effects artist.
What do i need to know to become FX artist?
I think most people become effects artists after having spent a bit of time in other areas. Effects is one of the more technical positions in a production so you really need to know a bit about everything. I personally started out as an animator and modeller, then spend a few years as a character rigger before finally getting into effects. The most important thing as an effects artist is to have a good sense of timing (Like animation). You don’t need to be an expert character animator, but you do need to develop a good sense of animation as it pertains to scene scale and to make things feel organic and natural. The trick is to use lots of reference. I am on youtube and vimeo all day every day looking for references to explosions, fire, etc. Case in point: I was the artist responsible for the alien fluid on District 9. For this effect I reffered to video’s on youtube such as this one of Ferro Fluid. Always, always always get reference! The Harry Potter vs Voldemort magic isn’t real, but it looks believable because the artists involved refereed to real-life elements
Do i need to know how to draw or paint?
I wouldn’t say so. I personally am not very good at either. I do however have a decently tuned critical eye as traditional artists do. If an audience member think something looks wrong or unbelievable, I can probably tell you why. “The nuclear explosion is moving too fast, that smoke is not being affected by those trees, that blood isn’t reflecting objects in the scene, that looks more like an oil fire than a forest fire”. Once you know what is wrong, then you can start fixing it. Again, this skill comes from looking at LOTS of reference.
DO i need to know Zbrush? Or Zbrush is just used for modeling, texturing?
I look at Zbrush as mainly a modelling tool. I personally prefer Mudbox because of it’s integration with Maya. If you know Maya already, the learning curve on Mudbox is very easy as it has a lot of the same hotkeys as Maya, and the same layer system as you have with Adobe Photoshop. I do think Zbrush is a step ahead of Mudbox in terms of tools and polycount, but I’m willing to sacrifice that for the ease of use. Saying all of this, most effects artists dont use either program at all.
And now the hard question, do i need to know some of programming language? Like Mel, MaxScript, Python?
Big question. In Maya for effects the most important thing is to learn how to write expressions. That is neither MEL nor Python. The good thing is that they are extremely easy to use. If you want to get right into effects, here is a tutorial I wrote a while back that will get you from knowing nothing about effects, to having a fully useable effects rig complete with particle expressions: Super Awesome Sprite Rig Tutorial
As far as MEL vs Python: I wouldn’t say you need to learn either, but it is very, very useful and not too difficult toget into. If you want to be a senior/lead artist you will eventually need to know at least a little. I’m solid in MEL and am currently trying to build up my skills to match in Python. MEL is pretty easy to pickup as you can just watch the script editor as you work in Maya to see what commands are being called as you work. Everything you do in Maya is called through MEL. (Python interacts with Maya via a MEL Library.) In my opinion, Python is a better language to pick up as once you know it, you have learnt the scripting language for many/all cgi programs out there. Houdini, Maya, Max, Real flow, Nuke… All are controllable via Python (and the programs libraries). The short version: MEL is easier to pick up, Python is more globally useful. I’d plan to learn both.
I am planing to learn this all alone, because i don’t really have money to go for a school, because it is so expensive.
You’re not missing out. Honestly. VFX schools right now are far overpriced for what they provide. If you can learn on your own you should do well down the line. I went to Vancouver Film School many years ago, but 99.9% of what I know was learned on my own from websites or in production. Be sure to keep looking online as there are tons of resources out there. Many instructors at the expensive schools cannot teach to more advanced levels anyways, especially in technical area’s like rigging and effects. I know for a fact the sprite rig tutorial I linked above is being used in many different CG schools around the world. If you can create that rig from scratch without looking at the tutorial… You would could qualify as an entry level effects artist in my books.
I am guilty of not updating very often. It’s been a crazy last few months. I am back in Vancouver after having finished work on the dragon sequence on Harry Potter 7, and getting some time in on John Carter of Mars. I was fortunate enough to work at one of the best VFX companies in the world: Double Negative. While I was only there for a short 18 months, I got to work with some incredibly talented artists and accelerate the ongoing learning which is life in VFX. While I was there, the team for Inception won Double Negatives first Oscar for visual effects, and they were nice enough to let me hold them for a quick photograph. (Forgive the wild hair, I was in crunch on Potter 7)
Now that I am back in Vancouver I’m working at Method studios on Abe Lincoln: Vampire Hunter. I’m super excited for this project, specifically because I am 100% working in Houdini. It’s been a real struggle for me to get out of my comfort zone in Maya and get into a totally different way of thinking. I mean, what kind of crazy person makes me use the space bar to rotate around a scene? I miss my alt key, damnit!. Now it sits there, untouched like a deformed 13th century handmaiden. All is well though, I predict Houdini is the direction effects is headed over the next 5 years. I don’t see it taking over for modelling, animation, or even lighting however. The node-based structure lends itself nicely to the effects workflow, and it it miles more open and customizable than Maya’s quickly aging fluid tools.
I moved to the UK in the beginning of 2010 and was lucky enough to be eligible to apply for an ancestry visa. The biggest benefit to getting an ancestry visa is that you don’t need a company to sponsor you. If you decide to change companies you can do without fear of being kicked out of the country the moment you are not employed. As far as being appealing to studios, a recruiter I spoke with in 2009 Ben Owen called the ancestry visa a golden ticket. It pretty much frees up any hiring hurdles a company might have with hiring a foreign national. Crossing into and out of the UK was a breeze as well. Actually getting the Ancestry visa was a bit of a pain in the ass though… It took a fair amount of research to figure out what I needed to get, what to send and to who and where. And this is what I did:
I went here:
Which sent me to here:
Which further sent me to
Finally letting me ACTUALLY apply via this link here:
All of the links above give bits of information in some form of information or another, but as far as documents go:
What they want:
Grandparent(s) birth certificates you are applying through, MUST HAVE PLACE OF BIRTH ON THE CERTIFICATE
Grandparents wedding certificate (if possible)
Parent(s) birth certificates, MUST HAVE PARENTS NAMES ON THE CERTIFICATE
Parents wedding certificate (if possible)
Your original birth certificate, MUST HAVE PARENTS NAMES ON THE CERTIFICATE
Your current passport
Any other passports you may currently hold
A passport photo taken in the last 6 weeks
Financial info – Previous 6 months of banking info
On the financial side of things they want to make sure you will be able to support yourself for up to 3 months if you cannot find work. You will not be eligible for social benefits/employment insurance/dole.
Actually doing it:
After filling out the online application and paying the few hundred dollar fee, you will be prompted to print your application and make an appointment to give your biometrics. The office is at 666 Burrard Street. Once you are there they will take fingerprint scans of all 10 digits, and another photograph. They will put your application, passport, and photograph in sealed official envelope. Next, is your supporting documents. I put everything in a nice binder, with a table of contents and a summary of all of my info, including my SIN, Carecard number, Date of birth, Drivers license number, and a financial summary of my assets/liabilities. Make sure it’s presentable and not a bunch of loose documents. This is a major tip! Make it as nice and professional as you can! Treat it like you are presenting yourself to a parole board. You can present yourself as best as you can but ultimately it’s in the hands of the reviewer. Take your binder, official envelope from the biometric centre and courier it to the address that you got from the biometric centre. Make it priority mail. It may cost more, but it ‘shows that you are serious’ about applying for a visa. They say it can take up to 12 weeks… I got mine about a week later.
There you go. You get an email when you are approved/denied, and they send it all back to you express post.
Some great videos I found made by a very smart Zeth Willie
Well my lovely girlfriend stole my 50mm canon lens. For such a cheap price it really is a beauty. Super small and crystal clear. I am tempted to pick up a second one because it is clear the first one is no longer a part of my kit haha. And because she is so sweet, she gets a new memory card.
Here is one of my earliest attempts at doing a VFX shoot to get a good HDRI for image based lighting in Maya. After taking the photo’s, I find I’m getting a better feel for what my settings should be for the bracketed exposures. I’m using my Canon 60D and the 18-135 zoom lens I got with it. Overall its great, but I can see why the VFX guys at Double Negative use a 8mm fisheye lens. I need to take 50-60 pictures to get a good 360 degree panorama. The 8mm lens lets you get about the same coverage on 9 shots (3 x 3 bracketed exposures). I’ve already spent waaay too much money on this gear so far to allow myself the new lens, but as soon as I can afford it, I’m getting a decent wide-angle prime lens. Here is a tiny, compressed, 8-bit version of the EXR I made. I’d host the file, but it’s 40 megs!. If you would like to try it out, email me and I’ll send you a link.
Not much to show for now, but so far it is a successful test building an HDR image for use in Maya.