I received an e-mail a few months ago from someone starting up in the industry as a roto artists asking for advice. I wrote down my go-to list of roto rules and then realised that there were a perfect 10 of them so I thought they would make a good blog post.
So here they are, my Top 10 Roto Tips:
- Break the objects down into much simpler shapes. If that means you have to roto each strand of hair separately then that’s what you will have to do. Pick one simple object and just follow it all the way through the shot, then go back and pick the next shape.
- Watch the motion of the object carefully before you start. To start with place your keyframes at the most extreme positions of the movement, then go back and refine the shapes from there. Use as few keyframes as possible.
- Use tracking data where ever you can. The point tracking in Silhouette is really good and the planar tracking in Mocha is amazing. Let these do the hard work for you and will allow you to use less keyframes.
- Try to transform your whole shape using the transform/rotate/scale tools before you start editing individual points. This will prevent boiling.
- Keep the control points of your shape on the same part of the object all of the way through the shot. If the point starts at the bottom of the guys ear make sure it stays there and doesn’t move to the top of his ear during the shot. This will cause your motion blur to be wrong and makes it harder to stop your shape boiling. If the outline of the shape changes too much to keep your shape consistent turn off your shape and start a new one.
- Keep your edge consistent. If your spline is 1px in from the edge at the beginning of the shot, that’s fine, as long as it is 1px in at the end too. The compositors can always slightly dilate or erode your matte but only if it is consistent.
- Make sure you know why the matte is needed. You can waste a lot of time if you roto areas or frames that aren’t needed.
- Learn all of the keyboard shortcuts for whichever application you are using. This will speed you up a lot.
- Keep checking your work with the solid overlay view. It is easier to see any issues this way than with your splines.
- Once you think you have finished your work check it carefully yourself before you send it to your compositor. Don’t worry if you think you are slow when you start, everyone is. Personally I think it is more important to spend a little more time on your work and get it right than try and rush it so you can send something that is wrong. In my experience people remember if they have to send someone’s work back for fixes again and again, but they won’t mind if it is a little late if they know it will be perfect when they get it.
If you liked this post check out my post on frame-by-frame painting
Hi Conrad,
I’m not working in the industry yet so thank you for these helpful tips. Generally how much time does your studio usually allow you to work on a roto shot? Days/Weeks? For example, I’ve only worked on clips of people and vehicles moving that are about 5-6 seconds long. To roto them accurately can take up to 20 hours of work depending on the movements. Would this be considered very slow for a studio?
It really does depend on what is happening in the shot, how long it is and how much detail they need. You will get a very specific brief about the areas that you will need to work to.
I can’t really say if 20 hours is too long without seeing the shot but I can tell you that I’ve worked on some shots for weeks.
In my experience everyone usually understands that roto artists are often new to the industry and don’t get too stressed if things take a few days longer than expected.
comming jitter. how to avoid it?
Hi Conrad
I am very interested to know your techniques on dealing with motionblur while rotoscoping please :). I use Nuke at work for roto, and I used to feather out shapes’ points for motionblur. Lately I have been rotoing to the solid edge of the object, then turning on the motionblur setting in the Roto node for Nuke to calculate the feather. It has been working quite well. But every now and then, I see that the motionblur calculated, produces the soft edge, but also eats into the solid edge quite a bit. I am wondering if it is better to roto to about half way into the motion blur, so that when the MB is applied, the solid edge doesn’t disappear so much…
I know that in motion blur is normally equal on both sides of a moving object, so I understand why the solid edge eating happens. Does Nuke expect me to roto to midway in the MB in the image for it’s MB calculation to work nicely? What is your take on rotoing MB in Nuke?
I will post this on vfxtalk as well to get other’s takes on this too 🙂
Thank you
Regards
Dylan
Hi Dylan,
Technically the solid edge would always appear to be in the middle of the motion blur because as you said the motion blur goes equally both ways.
I would always try to keep the spline in the middle of the motion blur and let the software get the motion blur correct for me but there are times when there is an obvious solid shape in the middle of some motion blur that you just can’t get to work correctly. In those cases I might move the position of the spline, or even create a second shape for the solid area.
At Framestore and MPC the roto department will always deliver a motion blurred version and a non motion burred version of their mattes to the compositor. In most cases the non motion blurred version was the same but just with the motion blur settings disabled, but some times you would have to duplicate the splines and adjust them to get either the solid edge or the motion blur in the correct place.
Hope that helps,
Conrad
Thanks Conrad, that makes a lot of sense to me. I appreciate your help and advice :)!
Dylan
hi conrad its very coool tips.thnks for sharing this tips.its very helpful.i hope u will post some painting(rig removals) tips also.
regards
maha teja
REALLY HELPFULL TIPS!!!!! 🙂
why india get only roto work to do …. where is 3d project….can any budy explain……
Roto is a one of the easiest parts of the VFX process to learn so it is easy to train people to do it.
It is also very time consuming and doesn’t need much creative input. The VFX supervisor doesn’t need to see the progress every day and make comments, they just need the roto done. This makes is one of the best steps to outsource.
There is some 3D work in India, and more parts of the process are being done there so it will keep growing.
Hi sir,
I want to start roto freelance. I have 4 years experience in vfx roto.
Can i start As a beginner small studio
Hello. Thanks for the roto tips, very helpful! The thing that I’m very interested in is how to remove initial background from motion-blurred areas when compositing rotoscoped footage. Can you please share some techniques on doing that, even general guidelines would be really appreciated. Thanks in advance.
Hi Denis,
There are a few common approaches to fix these issues.
If there are only a few frames of motion blur I usually just hand paint the FG colour into the motion blur area with a clone tool. I do this on the original plate before I premultiply it with the roto.
Another approach is to use an edge extend technique, sometimes called colour dialate. This used a non-motion blurred version of the matte and a combination of blurring and premultiplying/un-premultiplying to smear out the FG colour into the soft edges of the matte. Check out the Edge Extend gizmo on Nukepeida for a simple version: http://www.nukepedia.com/filter/edgeextend/. Be sure to open up the gizmo and try to follow what is going on inside.
There are lots of variations of this technique, I find that lots of small steps usually gives a better result than one big blur. When you first see this working it is tempting to just slap it on everything but with closer inspection you will see that you loose fine edge detail so only use it sparingly. I usually do some loose roto and keymix this onto only the edges that need it.
At Framestore we would usually deliver two versions of the roto, one with, and one without motion blur switched on, but you can always take the motion blurred version of the roto and use a gamma node to crush the feathered edges.
Thanks! Will try those out.
Hi Conrad. Thanks for sharing your valuable knowledge and experience. In new (may be not too new anymore) Silhouette, Mocha’s Planer Tracker is already licensed. I see you mention above point tracking in Silhouette and Planer Tracker in Mocha. Do you still need both software for that? If not, is there anything else in Mocha Pro that complements the strengths of Silhouette? Thanks again! Regards, Alkesh.
Hi Alkesh,
I haven’t used Silhouette or Mocha much in the past couple of years so I haven’t tried the newest versions of either.
I know that Mocha Pro automates some basic paint work. I haven’t tired it, but from the demos that I have seen it only really works on simple situations, that would be easy to fix if you have Nuke.
Mocha does have some basic camera tracking included now. Again, I haven’t tried it, but it might be useful.
Thanks Conrad. I haven’t used Nuke so far, but use Fusion for comp and SynthEyes for 3d tracking. I just ordered Silhouette today! I will probably put out some youtube tutorials once I get a good handle on it.
Thanks again for your quick feedback.
Regards,
Alkesh
I’m sure you can do the same paint work in Fusion.
I hope Silhouette works out for you.
I work in production house and Im a fresher doing stereo rotoscope… I’m having speed related issues. My speed is not so fast but due to pressure from supervisors I have to work in speed but that work is not good to get approved. Can anyone tell how to improve speed with quality work..?
Some things you can try:
Make sure you aren’t creating too many keyframes. Pick the frames at the end of each movement, and set the keyframes there, then check the shapes in between those points and only adjust if you need to.
Use as much tracking as you can.
Make smaller shapes. I find it faster to do lots of small shapes rather than a few big shapes. You will spend less time adjusting the shapes on each keyframe if they are smaller.
You will get faster with practice.
Sir i am just started working working in a vfx industry as a roto artist on 2 month internship, but sir i am very slow at my work. what i have to do when a shape changing in every frame , how to work fast with good quality and without any point glittering?
Sir please help me …
Sorry for the delayed reply.
You should really avoid changing your spline on every frame if you can. Try using tracking data to move the shapes for you. Also, try setting keyframes at the extreme points of the movement of the object first, then go back through the frames in between and only set keyframes if you have to.
is there any way to bake the planar tracking info of the new version 9 planar tracker just to the roto?
when I use motion blur on planar tracked roto I get stranges artifacts on some frames due to bad tracks.
with the old planar track it was pretty simple. if you disconnect the planar tracker from the roto nuke ask to bake all the info about the track on the disconnected roto.
I’m afraid I don’t know. I haven’t used Nuke 9 yet. Sorry.
About Roto connections are hard to assamble.confusing.plz explain to know me easyly.
I don’t understand your question. What are you finding confusing?
Hi Conrad,
I am a film music editor and at the end of projects create Blu-ray discs containing 7.1-track 96K versions of the scores for archives and in house refs. As part of that process, I make a menu system with characters from the films pointing at the various tracks when those tracks play. In animated films, I’ve been able to get clips of single characters with an alpha channel, which work perfectly for this. However, for live action, or where there isn’t the material available, I’d like to be able to extract a character from his or her background and then place them in the menu system (please forgive my ignorance of the proper vocabulary for this process.) Would Silhouette Fx be the best tool for this? Is this “object extraction” technically “rotoscoping?” And finally, would there be a tool in Silhouette that allows one to “automatically” detect edges based upon color or luminance differences? I’ve done edge detection in Photoshop for photo work, so was wondering if there is a similar technology for edge detection in any of the Roto programs. If so, it seems that might be a way to get close to a shape and then just convert the pixel based selection to a vector based selection for cleanup…or not? (Not being a visual guy, but a music guy, stick figures are kind of the extent of my illustration prowess. Ha!)
Thanks in advance and thanks so much for your patience with these questions from a rank amateur!
Tom
Hi Tom,
The term for ‘automatic’ background removal, based on colour or luminance, is keying. There are lots of tools for keying, but the two I’d try, if you have access to them, are Nuke or After Effects. Within those applications there are many different plug-ins or techniques you can use to pull a key. Often, you have to pull different keys for different areas of the image, and combine them. It isn’t automatic but if it works it can be easier and produce a better result than rotoscoping.
If the image isn’t suitable for keying then you will have to rotoscope the actors. Rotoscoping is the process of manually creating a matte for the image buy drawing lines around the edge that you want. Silhouette is the best tool for this, in my opinion, but you can also do it in After Effects or Nuke, and depending on the complexity of the image, and the tools you already have access to, it might not be worth buying Silhouette.
There is also a tool in After Effects called ‘roto brush’, which is supposed to work like the magic wand from Photoshop, but on moving images. I have never used it, but I’ve heard it can work well sometimes. There are lots of tutorials online for it. It would be worth checking out if you have access it.
Thanks, Conrad. That all makes sense. I believe my backgrounds are too complex to be keyed as you describe. I do have After Effects as part of my CC subscription, so will take a look at that. I believe they also have a Roto program call Mocha bundled with it, but knowing how these things usually work, it’s probably a stripped-down version of that. And from what I’ve read Mocha Pro isn’t any better than Silhouette for roto work. I’ll try the “roto brush” in AE and see how it goes. Otherwise, looks like maybe Silhouette will be the ticket.
By the way, thanks for your generosity in taking the time to answer all of the the questions on your blog. I know from my own work how much time and energy it can take to help out the guys coming up. Worth it though, and a nice payback for all of those who helped us!
Tom
P.S. By the way, did you do any work on “Pan?” I just got back from London doing post production on that Joe Wright film. Gorgeous VFX work in that one.
You can do some decent roto in Mocha, it might be worth a go. I’d forgotten that it is included with After Effects.
I didn’t do any work on Pan, but I think some of my friends at Framestore might have. Glad it looks good.
Hi Conrad,
I’m new artist for roto..
How to speedup my work in roto..and also how to improve my quality.. Thanks in advance
I can’t think of much more advice I can give you other then what has already been written on this page and in the comments. If you have a specific problem then I can try and answer that. But generally the best advice is already here.
hi Conrad,i need your thoughts on takeing rotoscopy only as a life long Career .and mastering it alone. iam just now staring my Career as roto artist.
roto will disappear from industry one day?i fear.
It might disappear one day. Technology like the rotobrush in After Effects are only going to get better. But they are a long way off yet. There will be a need for rotoscoping for years yet.
But why only concentrate on rotoscoping? Why not master roto, and then learn paint and compositing too?
Hai.Conrad tomorrow i am going interview for roto artist (fresher). your tips a very useful for me at the same time it’s a basic steps.I am expecting from you more than this.. thank you for your tips ..Conrad sir:)
Hi. I’m glad you found the tips useful. I’m sorry I haven’t posted any more. It is hard to describe roto techniques in words, and I haven’t done any serious roto for quite some time now.
Good luck with the interview!
Thank you Conrad
How to match a motion blur in shilloute
Usually you just need to turn motion blur on for your splines. If you have places the splines correctly in the middle of the motion blur, and they move correctly between frames it should be pretty good with the default settings.
Hi Mr.Conrad ,
thanks for your tips first .
second : what is difference between ” B-spline & x-spline ” , and what you prefer ?
thanks .
I’m glad you found my tips useful.
I haven’t used Silhouette for a while now and I learned with the B-spline. The x-splines were only added after I stopped using Silhouette regularly so I haven’t never used them properly.
I just had a quick play with one, and looked in the manual, and it seems that by default the x-spline is exactly the same as the b-spline, but it has the flexibility of allowing you to change the behaviour of each control point to cardinal/b-spline/corner. This is looks every useful to me. Maybe I should try them next time I use Silhouette.
If anyone knows of any issues with x-spline, please let me know.
I still say x-spline is the best….when you move them wierdly they don’t have tangent issues like beziers…they tend to bend more naturally.
This is really helpful! Thank you! Can I ask how you learned to roto in the first place? Could you recommend other resources? books / websites / videos etc? Thanks 🙂
Hi Rebecca,
I’m glad you found this useful!
I learned rotoscoping when I went to Escape studios: http://conradolson.com/escape-studios-complete-compositing-course
The whole aim of the course was to teach you compositing basics and to get you into the paint and roto departments of the big London VFX houses.
I have seen a few video tutorials but they are all a bit brief. I can’t think of any off the top of my head I’m afraid.
Thanks! 🙂
Very useful tips Thanks. I have one question while rotoing something like a hair or fur with open spline is there a way to gradient the opacity for example hair strands usually are opaque in the beginning and semi transparent in the tip or the end. How can you achieve this with open splines. I just see overall opacity controller, is there any other way. Please help Thanks in advance
Hi Anup,
I have only used the open splines a few times but I haven’t seen any control for the opacity over the length of the spline. It could be useful. Maybe you should put in a feature request to The Foundry.
Thanks Conrad. Got an alternative by masking the roto with a ramp node but doesn’t seem to work as expected. Maybe like you said if the foundry can put a feature to control opacity over length right in the roto node that would be great. Thanks again. An yes i’ll put in a feature request
Conrad, give me two important tips for tomorrow interview pls
I’m not sure what to suggest. I think the best thing I can say is to be honest about your abilities. They won’t be expecting you to be an expert. But if you make out that you a much better then you actually are they will discover that quickly and won’t be impressed.
when i doing roto in fusion flickering getting how do to stop flickering in roto and shapes are changing in last frames what can i do please suggest me
I’ve never used Fusion so I can’t give specific help but the issues you are having are probably not specific to the software.
When you say flickering do you mean they are jumping around, or is opacity changing? If they are jumping around then you you read points 1-5 above. They will help you.
If the opacity is changing you might be having motion blur issues. Make sure the shape is moving consistently between frames.
It’s hard to tell what you mean when you say “shapes are changing in last frame” so I’m going to guess. Usually there is a motion blur issue on the last frame because there needs to be motion before and after for motion blur to work properly. The solution is to add one more frame of animation to your splines. If you don’t have enough footage you just have to estimate where the movement would continue to on the next frame.
Hi Conrad !!
Thank you very much for these tips !!
I have been working on Fusion since last week, still I have not been able to minize the boiling of the points and in some low quality shots, I used to left out the edges. Can you please help ??
What to do if a plane smooth shirt of the arm turns out to be wavy and we need to add more points to cover it up, that just gets out of control !!
Please help !!
You should break the shirt up into smaller sections. Maybe even a different spline for each wrinkle in the shirt.
Hi
Can you please explain how to do defocus and match motion blur roto please
If you place your spline in the middle of the motion blur of your image, and are carful to animate evenly between frames you should be able to use the motion blur feature of the software to automatically generate motion blur.
The defocus should be done afterwards as a separate step. Sometimes it’s just left to the compositor. It’s usually fine to just use a blur node in Nuke and animate the value.
Thank you
Hi conrad your techniques are very usefull
I wanna ask you that when I doing roto motion blurred footage in silhoutte I have to switch spline per frame for better results but I know that this is wrong techniques but I continue animate the spline some frames, motion blur did not match proper and hard edges not match what I do plz solve my problem
Motion blur will not work if you have a different spline for every frame as it needs to use the movement between frames to generate the blur.
If you really have to use a new spline on each frame you will have to create the motion blur manually. The feather took on the spline will probably be the best option. Place the spline on the hard edge of the object and then pull out the feather to cover the motion blur.
Hello Mr.Conrad I have entered Industry recently. I am a fresher Stereo Roto artist but my goal is to become compositor so I need your help ..please share your valuable words regarding. How should I plan my career further? What is the next department I need to focus and softwares as well.
Hi Chaitanya. Thanks for your comment.
I have written a lot of detail about how I progressed through my career in the “career” section of this website. Please read through that. If you have any questions afterwards let me know.
If you want to become a compositor you basically just need to work with Nuke. But knowing Silhouette and Mocha will help too.
Hello, thanks for sharing such helpful tips
I’ve been working on a shot where I Have to roto white hair on greyish background. It have lots of movement and lots of blur. Can you please give some advice to make this work quicker? Maybe something like power matte in shilloutte 6 can help me but I am not entirely sure. Also I’ve been already working with open splinter and however they are helpful it’s still tediously slow. I would really appreciate the advice as the deadline is horrible close and I still have 80% of work left.
This sounds like a very hard shot. Sometimes that just takes time.
Trying to pull a key is useful sometimes, but if you’ve been asked to roto, sometimes they just expect you to roto. Compositors can try and pull keys.
Also, white hair on a grey background is going to be hard to key.
I don’t really know what help I can offer, except make sure you get the basic stuff done first, so at least the matte will be usable, then spend time adding more and more detail. Don’t try and do all the detail in your first pass. Hope this helps.
Conrad
Thanks for you tips
I am beginner in silhouette.as a beginner I am mostly confused in blurred frame that I want to cut.if I cut the green colour can be seen .so inorder to reduce green I use motion blur but it makes start boiling so I am confused In these part.so can you help me?
Hi Souhrida, I’m sorry for the delay in replying. I didn’t see the comment come through.
I don’t fully understand your question, but it sounds like you are worried about the background colour coming through the soft edge of your roto.
This is ok and is something that is always going to happen. As long as your roto is consistent, and in the middle of the soft edge, this issue something that is up to the compositor to fix, not you. Don’t try to add edge blur to fix it.
Hi Conrad, ty for so much info on Roto and it’s methods etc. Do motion blur shots always need swapping of splines on each and every frame ? Also, too much swapping of splines is considered good / bad ?
Hi Sayali, sorry for the delay in the reply. I didn’t see your comment come through.
You really should avoid swapping the spline on every frame, you won’t get the correct motion blur if you do that. If you can keep the same spline through out the shot, and you animate it correctly you should be able to get the correct motion blur automatically, or at least get close.
You should only start a new shape if your the object changes shape so much that your existing spline no longer makes sense.
Hello! Thank you very much for your precious tips and advice that will help me a lot. Currently, I don’t know why but I’m struggling to do roto. It’s like My brain refuse to know if my roto is good or not. I’m very mixed up with all technical of view for Tech check. And each type a move my roto it’s not seems write in one method but good in another one. In fact, the roto for see if is good I just too look with a grey constant and if I don’t see the background (exemple roto of a character) and show perfectly my character, my roto should be good right ? Thanks you so much ! I feel like I’m stupid to don’t get it right 😂
I’m afraid there is no easy answer. What is ‘correct’ when you are rotoing depends on what the compositor needs and what the supervisor expects to see.
If you object has soft defocused or motion blurred edges then you might expect to see some of the background showing through the grey constant. It would be the compositor’s job to treat the edges in a way that would remove the background information. Personally I would rather the roto included the correct motion blur, but had some BG bleeding through. But other compositors and supervisors would rather have hard edge roto that is tight up to the very last solid edge of the object you are creating a matte for.
Sometimes you don’t know if the roto is going to work until you see in working in the comp.