We’re happy to announce a new round of summer internships through bitfilms on Wires for Empathy aka the tube open movie project.
Read the details in this document – it should contain everything you need to know, deadlines, how to apply, etc.
In brief we’re going to be working on two exciting main areas, timelapse animation and lighting. In the run up to the internship period I’m working on documentation for our lighting pipeline and timelapse animation workflow and tools – so if you’re into lighting with cycles, would like the chance to work on our color-managed lighting pipeline, or if you like the idea of animating things changing over time, or modeling snapshots of aging objects, this could be a good fit for you.
We’re happy to announce a new round of summer internships through bitfilms on Wires for Empathy aka the tube open movie project.
Many of you have warned me that code I hastily threw up on pasteall.org and the like no longer exists; those pastes expire and leave a sad internet of broken links behind them.
I’ve decided to adopt the stop-solution of a couple of gitlab mega-repos to solve this. This’ll keep the code out there, and enable people to collaborate (all of it is GPL code)
I highly recommend you do not use it! It’ll work on simple files (and even complex one) but it’s hopelessly slow, and really hacked on without good support in Blender. Forewarned is forearmed!
This is barebones but extremely promising – oddly, unlike the floating sliders, I don’t see any downside here. It is however, a proof of concept, and needs adapting to your own rigs (or fleshing out features)
It still works I think!
I haven’t documented this anywhere – it basically supersedes typewriter text as it allows more effects such as counting up and down, blinking, etc. and allows combining them together. It’s stack based and pretty hard to understand (would be better as nodes) but it works and I’ve used it in production.
Some of the addons we use for Wires for Empathy – mostly the more polished ones, or the ones that are not too project specific.
An object oriented crowd simulation and autowalking tool.
Early last summer I was faced with a problem: As we completed a set of pre-planned and conceptually regular animation shots, our original approach to handing out tasks to artists started to resemble a research project: Delve into the files and preview, identify a ‘high priority’ item, then break it down to bite-sized tasks that could be reasonably executed by one person.
But each of these bite-sized tasks depend on one another; so the assignment often fell into order-of-operation problems – before you can rig something you need to model it, and before you light something you need to have it textured, etc. Since multiple assets link into multiple shots, and often times you need to do the same ‘type’ of task on one shot, this gets really complex to figure out- and once you’ve done it once, it’s good to be able to store those relationships in a logical way for future reference.
Helga, our web based production tool, has a good attempt to fix this. But it is hard-coded to a specific workflow, and tends to isolate individual shots and assets so they don’t reflect their interdependence. Each shot and asset has a task tree that looks like this:
So the next step is using spreadsheets. This is what Caldera – the previous drome project – used to do, essentially supplementing Helga with google docs. We did quite a bit of that too, often using libreoffice to make spreadsheets, and sharing them using google docs – in the future we’d like to use an opensource document collaboration platform, the likes of which collabra and libreoffice are implementing as we speak!
The problem with spreadsheets: Everything is on a neat grid layout. That makes it easy to enter and read information, but it actually hides the structure of the data underneath. Our data consists of tasks that depend on each other in a specific order, in a kind of network that has a direction to the links. In computer science, there’s an obvious data structure to use for this: It’s called a DAG, short for Directed Acyclical Graph . Basically a network of nodes ( a graph) where each link has a direction (from node, to node) and you cannot have a cycle – either directly or indirectly, you can’t have an infinite loop of nodes (imagine if rendering depended on animation, but animation depended on rendering – you’d be stuck in a loop and could never finish the project! ). Any proper representation of our task list should reside in such a graph, fitting the data to the data representation:
So, as luck would have it, Blender has a programmable DAG editor – the node editor. You’ve probably seen it in screenshots, or used it yourself, to make shaders in cycles, materials and textures for blender internal renderer, or to composite images and renders. In addition to these ‘normal’ uses of the node editor, there is a hidden feature: Blender allows you to create entirely new node network types and node types in python. This has been used to make excellent addons, such as sverchok for procedural modelling, and animation nodes for procedural animation; It might become the basis of all rigging, modelling and animation in future future versions of Blender.
But for our needs, it’s a convenient way of organizing the project! By creating a new node tree type in python – dependency nodes, and a new node type – a task node, we can give each task some properties and some dependencies, such as:
- owner – the name of the artist or coder working on the task
- time – estimated time needed to complete the task in person-days
- type – type of task: is it animation? rendering? texturing? etc.
- reference – what shot or asset is the primary reference for the task (refers to shots and assets in the helga asset list)
- Completion – Is it done or not?
- Dependencies – These are links to other, similar tasks that much be completed before this one; other tasks might have this one as dependency in a similar fashion.
Getting Data In and Out
The primary way of data entry is right in the node editor: Use Shift-A, or the handy panel on the left to create new nodes. Copy, paste, and duplication all work, as does the usual way of connecting nodes. However, we recognized early on that we’d probably need some other connectivity. I created a JSON file format for tasks, and some simple operators to export tasks or import them from JSON files. This helped automate data entry from sources we already had available. We also know that many people find spreadsheets far more user friendly then nodes – and not everybody has to deal with the dependencies. So we made spreadsheet import and export – currently using .csv files (this could be improved a lot – we aren’t even using csv libraries in python) – but it works fine for our current needs. You can export all or part of the graph to spreadsheet/s, edit those spreadsheets (or create new ones) and then import the changes back into the graph. This makes communicating with the rest of the team fairly simple.
In order to make import and export easy, We have a ‘Search and Select’ function that lets you search for specific things, for instance, you can search for all character animation tasks, and then export a spreadsheet just for those. This is handy to then use for communicating with animators and animation supervisors. We can even modify the spreadsheet – assigning animators, or adjusting estimated time or completion, and then re-import back into the graph. Search is of course, also useful when working directly in the graph, without needing to import or export anything.
Lies, Damn Lies, And Statistics
Finally we have have stats and reports. If Nothing is selected, it adds all the uncompleted task times, giving a total project estimate (in person / time units) Note that our current total is a bit inflated as I tended to pad tasks out – especially tiny ones – things that might take an hour or two have a whole day. This number also assumes only one person working, and no corners being cut. If you have a selection it displays the time for the selected task/s and all its/their dependencies. Thus you only have to select the final render for a specific shot, and see how much time it takes to complete it.
While writing this code I wanted to get something ‘up and running’ really fast. At the same time, I feel like this could be more useful in a bigger system. So, to describe the data structure of an individual task, I decided to keep all of this in one really simple class/module, that could then be modified to hook into another library, or to change class types for a given project, etc. without having to touch the rest of the code. While the name is inspired by blender’s sDNA and sRNA systems for data storage and access, this is in no way as elaborate or cool. But it still allows for really quick and nice additions. If you’re looking to take this and integrate into your own system, look at the file taskdna.py first!
In the future I’d like to tie this as a small piece of larger asset/task management systems. That means that there needs to be an api to connect to various project databases, and the taskDNA also needs to be part of that api, allowing the system to define not just the tasks but the actual data structures.
A small part of this that might be cool is enabling image previews in the nodes, reflecting the current status of those tasks.
The current version is zipped and installable via blender’s user preferences->addons panel, get it here: tasker version 0.2
You can also download this project along with a lot of other addons for tube from my gitlab: tube addons project
The files are located in the folder tasker/
Once downloaded either:
- make a zip file of the entire tasker folder then install the zip as an addon in Blender
- if you’re technically inclined, make a symbolic link within the Blender addons directory directly to the tasker/ folder – that way you can git pull it and see the changes directly in blender without having to re-install.
From Politicians to Tasks!
In the import function I wanted to sort the nodes based on the dependencies, so they could be displayed in a nice layout in the editor. DAGs have well known sorting functions, but I didn’t want to implement my own. So, I borrowed code originally written by Paul Tagliamonte for the Sunlight Foundation – It turns out that following the trail of money and influence on politicians is also a DAG, and Paul wrote some beautiful BSD licensed Python for sorting and cycle detection. Thanks Paul!
As a bonus image, here’s the rendered frame produced via the screenshots above: Finally thanks to everybody here – I hope this post satisfies those of you who, like me, are geeky about this stuff. To them, and everyone else I promise more new cool artwork in the next update!
*The current name is ‘tasker’ but I’m switching to orgnodes as a pun on emacs org mode.
Hi there !
Last summer, while I was visiting the Urchin crew during my summer trip, I’ve spent a few days working on Tube in the nerdodrome. With Bassam, we had a discussion about cracks generation for the timelapse sequence. The environment for Wires for Empathy is mainly composed of concrete and we thought it would be kind of cool to have some nice cracks growing on the walls. Generating cracks is not that hard, we can do procedurally, with some great results. This tutorial explains how to do it fairly simply.
However, animating the cracks is a little bit harder and we cannot rely on the procedural method any more. We searched for examples and papers of people who already worked on this problem and found some great material. Unfortunately, most of the papers we found where based on heavy research and would include some serious C/C++ coding in order to have these tools inside Blender.
The python approach
Our first idea was to write an OSL shader that could generate cracks with some growing parameters that artists could use to control the speed and shapes of the cracks. Moreover, our rendering pipeline is entirely CPU based so using some OSL would be a problem. I’m sure it is doable in OSL, but I don’t know this language at all and even though I’m willing to learn this shading language, I would have spent a lot of time of time learning it, without being sure that I could achieve the result I wanted.
So I chose to use Python and to create a script that would manipulate Bezier curves to generate cracks in a procedural fashion. The generation algorithm is fairly simple and a based on a “branch” approach. Complex cracks can be splited into small simple “branch” that can be easily generated and manipulated. To do so, we have a very basic recursive algorithm that create a branch a determine the position of its children on it. We then repeat the branch generation on the children and determine its ow children and so on. The following image shows how a complex cracks can be seperated into those branches.
The following image explains our approach to approximate the shape of a crack. We can see that crack can be split into big segments (in blue) that can be split again into smaller segments (in red).
In Blender, we define a general direction for the branch, and generate points along it with small angle variations between each point. By default, every 5 points generated, we created a bigger angle variation (corresponding to the blue one in the image). We then convert theses points to a Curve Object.
When each point is generated, we generate a random value between 0 and 1 and look if this number is smaller than the Children Probability defined by the User. If it’s the case, we create a child branch at the point position and store it’s relative position on the master branch. For example, if the tenth point of a branch composed of forty points has a children branch, we create this new branch with a ‘relative position in the master branch’ of 25%. This will be very useful when dealing with the animation.
As the algorithm for branch generation is recursive, we need a way to stop it. To do so, we simply decrease the child probability at every generation, so each generation of children is ten times less likely to have children than its parents.
More displacement on cracks
The previous image shows how, even if we have generated cracks with big angle values, it still appears too smooth. We need to add more displacement on the cracks. To do so, we subdivide each curve several times, select randomly some points on it and move them using the proportional editing tool with a random falloff. After some test, we found out that we have much better result by repeating this operation with small values several times instead of doing it in one go.
The result is far more convincing with little displacement along the cracks. However, this step currently produce a small but annoying bug where some roots of some children branch get disconnected from their parent because they are displaced under the effect of the proportional editing tool. This bug is currently being fixed.
The animation system is fairly simple, we key the End Bevel Factor parameter to animate the growth of a branch. However, by doing such, the growth is very linear and robotic. So, we have added a parameter to control the speed of growth and make it randomly go faster and slower during its generation. We simply subdivide the F-Curve for animation and change the position of the keys in the Y axis as illustrated in the following image :
The result is visible is the following video :
The script is used to generate the cracks and their animation as you can see in the following video. We use custom attenuation and displacement on cracks to get a more believable result.
In order to make cracks interact with other object and surface, we need to export it as a sequence of images with transparent background. We will then be able to plug this sequence into a material or a modifier in the scene and generate cracks easily in the scene. On the left we have an example of one of these image. To render it, we simply do an OpenGL Render from the top view with an orthogonal camera. We also have applied a simple material with a black&white colorRamp so we can destroy the edge of the cracks later on.
The image sequence is then used in the scene file, as a factor for displacement modifier on a highly displaced plane and as a mix Factor on the concrete material. As we have loaded an image sequence, we only have to set the right number of frames to use and Blender will automatically refresh the image number to match the current frame and we have our animated crack !
Todos and limitations
Currently, the tool is very limited and could be largely improved by adding new features like cracks generation snapped directly on a 3D surface. This is doable as we first generate a point cloud, we could snap each point on the target surface as we generate them.
One of the biggest limitation is the fact that we don’t have access to all the modifiers we want as we manipulate curves. For example, we don’t have access to dynamic painting or boolean modifiers. Keep in mind that this a tool to generate background and secondary animation in some timelapse sequence. Our needs are quite limited and our plan is to generate a few different cracks that artists can then plug easily into their scene and add some details without spending days with painting cracks manually.
The script can be download here. For now, it is only a script, so you’ll have to load the file in the blender text editor and run the script from here. Cracks Generator is added as a new tab in the tool-shelf of the 3D View.
Hello everyone! We’re very sorry about the slow pace of updates in the past – we’re trying to do better with this and we’ve resolved to fix this in the new year. We really appreciate you patience and kindness in waiting for us and supporting us so far, and hope that the film will justify your expectations and your support.
The fact that we’ve been slow on updates, doesn’t mean we haven’t been working on the film – we’re a tad resource constrained but making progress nonetheless, with a good sprint last summer and some steady work since then. A lot of this work is technical, but there’s a lot of art and results to show from it.
Last summer we had high occupancy in the Drome (2 local artists including myself, 3 students, and a visit from Henri who worked with us for 2 weeks) since then we’ve lost the students to their classes, but otherwise work has continued smoothly. We’ve been working on a wide variety of areas, including 2D art (for signs, posters, and miscelanous in the station) animation, lighting, and coding. And of course, much of the work has been done by artists working remotely.
It’s about time we show some of what we’re working on (It’ll be a in a mix of progress from begun to complete), and to show what’s left to do for the movie completion. In other words, it’s time for some pictures, videos and some stats 🙂
we have a total of 48 shots in the project. Of those, there are 4 that aren’t done (one of those currently being worked on) and 7 that currently need fixes – ranging from minor tweaks to reanimation. Incidentally, the 4 shots that are not done require some effects animation – they are highly technical in nature, and we pushed them later in the schedule so we could beef up our technical pipeline and make them more feasible. (more on this later) The following are examples of some of our animation fixes (after fixing): Animation fixes by Gianmichele Mariani, Chris Bishop, and Tal Hershkovitch, based on original animation by Virgillio Vasconcelos, Luciano Munoz and Jeenhye Kim.
This is a very complex challenge, both artistic and technical. There are 18 timelapse shots in the film, of varying difficulties – 3 of them are done, (but do need a few tweaks), the rest not.
There’s a massive technical challenge to these shots, so we’ve been building our technical pipeline to make them work. These shots should go next.
As you’ll see from the next examples, these are being done wholesale: animation, lighting and rendering – due to the importance of surface detail during timelapse, we need to see their timing in connection with everything else. Here’s two examples a2s49, and a2s21 – the latter was tweaked over the summer, the former was started this summer only.
There’s 8 of these in the film, with 3 left to do. We split this up a bit: some just require a bunch of animation using the built-in tools in blender. These are mostly shots that are ‘2D’ in motion: characters that walk in straight lines across the camera. For the more complex/ three dimensional shots, we’ve built a functional crowd system, that’s gotten constant revisions over the course of the project and reached it’s final phase during the summer. Here’s a little preview of what it can do on one of those 3 in progress shots (there’s still a bit of tweaking to do here):
missing in the above preview is the foreground and background character animation (both complete) – oh and by the way, the same crowd system works for any character rig, including humans.
There’s a scattered mix of animation that doesn’t belong to any fixed category; we could call it background animation or object animation. It’s hard to tell what’s done here as a lot of it is optional – improving a shot rather than making it, while some is needed to make the shot work. The latter is planned and done in advance, while the former is done on an ad-hoc and as-needed basis over the course of the project – things like gravel crunching and moving underfoot, or bits of paper flying in the air, or a railing or window flexing as the character interacts with it. The following examples are some older shots we have showing those types of animations. There’s quite a few to do, most of them much more limited (but some complex ones that are a bit too spoilery to show 😉 )
One neat example of this type of animation is the work Henri put in to animating the title sequence of the project:
Code and Shaders – Timelapse challenges
While there is still some character animation to finish, and we are not finished with texturing/materials/lighting and rendering, our current big push is to finish the timelapse animation. There are some interesting challenges to the timelapse animation that aren’t present in ‘normal’ character animation:
- Instead of just ‘camera, characters, and props’ we have many shots (roughly a third of the film) where literally everything on camera is being animated.
- Timelapse changes don’t just deform object, they change topology, or get replaced whole.
- In a typical shot we don’t animate the surface materials, but those become the most critical part of a timelapse.
- Because this is unusual animation, the built in tools of animation programs (like Blender) aren’t optimized or setup to make it really easy – compare to character animation that gets a lot of attention.
The following is a material test, showing how timelapse materials have to animate over time in interesting and believable ways:
So we attack the problem from general to specific and from specific to general. We work shot by shot, finding problems and solving them. But then we spend time analyzing our needs and developing tools and reusable assets that will work for many shots.
One such shot is a2s49 (shown earlier), a cut-away shot, and one of our tools is a blender plugin called timelapse toolbox that has many features we identify and add to it along the way. More elements that we know we’ll need, we can tackle on their own: Cracks growing, Aging materials and surfaces (think rusting metal, peeling paint, concrete, etc). All results from these are also assisted and lead to modifications and additions to the timelapse toolbox, in this case dealing with material animation, and also to a growing shader library that will be used across all shots.
Another really interesting plugin is the crack generator by Henri Hebeisen. It’s a fully procedural python program, that generates cracks that can evolve over time. Highly flexible as to shape, timing, and placement, it generates animated Blender Curve objects that can be rendered to textures, shown directly in the viewport, or used as brushes for dynamic paint or boolean operations.
Another important tool that was completed recently is our meshcacher – a tool designed to add features to Blender’s current limited caching capabilities. Since timelapse toolbox, the meshcacher and the crack generator are interesting technical topics, we’ll cover them in more detail in future updates.
Lighting and Rendering
With the focus on timelapse and animation fixes, we still found some time to light some of the non-timelapse shots. Here’s an example of lighting from Vincent Gires, on a1s16 (finishing up work by Christine Stuckart in an earlier phase of the project):
2D Art and textures:
Before the shots can have final renders, we need to produce many bits of 2D artwork, to be used as posters, advertisements, and so on the station walls – even signage and graffiti are important elements in the timelapse, and to add detail to the station. We also want the location of tube to be universal, not a specific country or place on earth, so instead of english, we’re designing a simple ‘font’ for an unknown language. The following is a quick preview of some of the posters. Art is by Astro Leon-Jhong, Michael Kalinin, myself and Anastasia Denos. Note all of this is in a mix of concept to approved art:
Planning and Organization
We found relying purely on Helga+spreadsheets to be sub-optimal for our planning needs; the high amount of interdependence between tasks was too much to plot, lending itself more to a network than a list. Luckily we already have a nice network editor: Blender’s node editor. So we wrote a simple plugin that creates ‘organization nodes’ and allows outputing into various spreadsheet formats. Here’s a screen shot of what we have to do:
So it looks daunting (and it is) but it is on a very high level of detail. the 3 columns represent the three acts of the film, so the bulk of our remaining tasks are in the second act.
In conclusion, thanks for your patience, and many apologies for the delays in the project and the long periods of time between updates. We’re resolved to do better in both regards, so we’ll have have more soon, showing technical milestones, new artwork, and project details.