The secret power of the space bar

In nuke you can do a lot with one hand on the keyboard and one on the wacom. I’m constantly learning new shortcuts. A great, subtle ui convention is that generally when a button has been selected in the gui, it can be activated again afterwards by hitting the space bar. It is also the same as hitting enter on dialog boxes that have a default button set. In general this is useful for dismissing dialog boxes like the flipbook one with a space, but I also love to use it while I am frame-by-frame tracking. Using a pen it is pretty difficult to repeatedly hit the same button while not looking at it. I like to hit the button once, then tap the space bar whenever I need to track the next frame.

5 ways to mess up grain

It’s easy to say “grain as late as possible”, but it’s more informative to list the ways that you can do it wrong. Here is a quick list of things not to do to grain:

Never grain before a blur.
Never grain before a grade.
Never scale the grain.
Never animate the grain separately from the clip.
Never grain before a tracker.

These rules can all be broken if you have a really, really good reason, but they hold true 99% of the time.


how to match camera move-induced motion blur

I haven’t seen this posted clearly anywhere and it is pretty simple. Here’s how to match motion blur. Track a point with a tracker node, pipe that node into the 2d transf pipe of the motion blur 2d node, and then pipe the result into a vector blur node. Connect your source footage to the other pipe on the motion blur 2d node and you ought to see some blur!


The tracker finds the motion, the motion blur 2d converts it into u and v ramps, and then the vector blur actually converts it into blurred footage.

If you have a camera track, then you can swap that and the motion blur 3d in to get similar results.

tips to speed up nuke

If I had eight hours to chop down a tree, I’d spend six sharpening my axe. — Abraham Lincoln

This link from nukepedia got me started thinking about smart ways to work and render. I guess the old ‘sharpen your axe’ adage applies here. Time spent making a script more efficient will almost always pay off in the end. I think that Scott Chambers nailed a lot of really good ideas in his post, but I’m all for continuing the conversation. These are a lot more entry level, but I think we have all fallen for most of them before.

Clamp values whenever needed. It is pretty easy to accidentally end up with values that are way outside of the 0-1 range. That can cause some more difficult calculations and is generally just a headache unless you are doing this intentionally. Clamp them in-node or with a clamp node to keep them nice and regular.

Delete unused channels. Cg just passed a 45 channel file to you. If you don’t need any of those layers, then cut them free. It takes clock cycles to process even the channels that you can’t see.

Crop to format. If you aren’t careful then your bounding box can end up way bigger than need be. Pay careful attention to that dotted line and it will reward you with faster renders.

Watch your RAM. Nuke loves RAM, so much so that it may be a little jealous of all of the other apps on your computer. Keep and eye on your process viewer and keep the number of instances of nuke/rv/whatever down to a minimum. Also check your useage whenever you have one of those facepalm moments where nothing is responding. More than likely you are running in swap.

Prerender/Precomp whenever possible. Keep the number of times that you need to render out that particle sim / heavy gizmo / oflow node to a minimum. Bake it out and bring it back in.

Turn overlay off. When viewing it in nuke, overlay adds a processor load. Turn it off.

Region of interest. Cut down your render area to get faster feedback.

Render out fewer frames. Render every 5th frame by adding a /5 to the end of your frame range.

And sadly, buy faster hardware. Nuke wants as much power as you can throw at it. Get more RAM, a SSD, an accelerator card, video card, faster network, or a faster processor. This is an easily justifiable expense when your time equals money.

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Nuke compositors gift guide 2011

This may seem like a very specific niche to make a gift guide for, but us nerds can be really tough to buy presents for. I like getting presents as much as anyone, so hopefully this gives some ideas for the significant-others of compositors world wide. This list isn’t super specific to compositors only. It could easily be applied to almost any visual professional, from video editors to animators to illustrators.

Wacom tablet. Do they have one? They might want an even bigger one! These are pervasive in the industry. A lot of artists cannot work without one, and they are actually very good at reducing repetitive stress injuries like carpal tunnel. Most people would be lost with the extra large tablet, but the large and the medium are both very useable. One note – while wacom does make a cheaper tablet called the bamboo it is generally avoided by working professionals.

Wacom pen. It’s nice to be able to shift your grip up some times. Maybe the airbrush style, or the classic pen will switch things up. Even if you buy them the same one that they currently have it can be useful. Many artists will wrap them in tape or modify them to make them more ergonomic.

Vfx books
The VES handbook is a bible for vfx, The art and science of compositing is another good resource. I would also recommend Digital compositing for film and video

In addition to books, there isn’t any better bang for your educational buck than in taking classes at fxphd. They offer a ton of different classes, and it is one of the best ways to keep your mind sharp, and to continue learning.

Stock assets
Something like the Digital Juice Compositors toolkit can be a lifesaver for quick turnaround work. They have a ton of stock flame, smoke, fog, steam, particle footage ready to use. When your creative says “I like it, but can we make him look like he’s on fire?” this is the easiest way to get there.

More Monitors!
Screen real estate is always at a premium. If someone has been really, really good, then maybe a 2nd (or 3rd!) monitor is deserved. The dell ultrasharp line is a very good bang for your buck, and the HP ZR24W is slightly less bang, for slightly less buck.

Fun Stuff
Movies – Almost everyone who works on movies is into movies. Get them the limited edition of that movie they won’t stop babbling about. For effects nerds the behind the scenes footage and extras can be as good as the actual movie.

Love – As much as it shouldn’t have to be said. We often work waaay too many hours, and having someone who understands us and can accept us for our passions and our odd job requirements is truly a gift in itself.
Domain name – If they don’t have their own domain, then it makes a great gift idea. They are really cheap- too!
Coffee-related stuff – We spend a lot of time thinking about how we wish we were not sleepy, so coffee cups, french presses, red bulls and high test tea are all appreciated.

We Be Jammin’ Good music can help a bad day go by quickly. Our jobs don’t often involve audio, so we can put on a track and jam out for a while.

Nice headphones
– really help you block out the background noise.
iTunes/pandora/spotify – Give them music to keep, or music to stream. They both have their virtues. One note about spotify is that not all artists will be able to install the client on their work computer, but there is an iphone app.
iPod – It’s nice to separate your music from your computer and your phone.

Stay Strong
We spend a stupid amount of time sitting. Any gift that gets us moving is a good idea. That could be yoga, spinning classes, a sports league, or even a hike. There are also a ton of things that make sitting for long periods bearable, like yoga ball chairs, special chairs, or standing desks.

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how to render every x frames

Good compositors know how best to use their render time. Poor time management can be the difference between iterating a shot 3 times a day, or 0 times. One great way to be conservative with rendering is to do a ‘test’ render of every 5th frame or so. Feel free to adjust that number up or down based on how long your shot is. That way you can see if you have any floating roto shapes or glitches faster. If it looks good, then go ahead and bang out the rest of the frames.
Luckily, nuke makes this easy. In the render dialog box type your frame range with dashes between the first and last frame. Then type a forward slash and the frame interval you want. i.e. if you have a one hundred frame long shot and you want to see every 5th frame it would look like
Then if your frames look good you can render the other frames by moving the start frame. If we use the same example as above then it would look like this

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hitch: frame range node probably wont do what you want it to

I would guess that the first time most people drop a frame range node they are expecting to be able to set a range, and then have that effect the images piped through it. I know I certainly did. It doesn’t work anything like that.
The real use for this node is to set a frame range for the downstream nodes. For example: if you were trying to track an animated object that didn’t have any read nodes in it, then your tracker would spit out an error that said something to the effect of “can’t track, no frame range.” That means it doesn’t know if it is before the start, or after the end so it’s not going to track at all. The fix is simple: put in a frame range node and set it to your frame range.


how to cancel a tracker in nuke 6.3v3 or below

Nuke 6.3v2 and below seem to have a weird bug where you can’t cancel the tracker once it has started. That can mean a really long wait before you are allowed to look at the keyframe data that you didn’t want anyways! I was poking around on the foundry’s forums today and someone suggested a smart solve for it.
Just unplug the pipe into the tracker.
It will force the tracker to stop. I have heard rumors it may make nuke crash, but I haven’t been able to reproduce that even once.


tough track? Maybe blame grain!

I have had a few really dark tracks lately that came out poorly. Nothing I did could make them any less jittery or more useable. In frustration I was venting to someone when they told me to try putting a smooth node on it. In this case I am using it like a degrain, but it’s faster and doesn’t require nukeX. I set the smooth so that it blurred out the bulk of the grain but didn’t get too harsh on the main image.
That actually helped a lot. The tracker has a tough time finding the pattern in the noise when there is a lot of grain, so making it easier for the tracker made it easier for me.

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nuke hotkeys guide

Nuke’s documentation is very thorough, but sometimes I want to see if there is a shortcut for doing something and I don’t feel like digging through a thick document. Victor Perez has put together a nice one sheet pdf with all of the hotkeys nicely organized. You can download here it from Nukepedia