How to use a Render Farm in Archviz

The major trend of recent years is to increase the consumption of visual content. More films, animations, business graphics, mappings and things like that require uninterrupted content delivery by visualizers. Production times despite the fact are only getting shorter. It all started with large render farms that film studios created for themselves. They were isolated from the whole world due to internal use and poor development of Internet channels for outside access.

The widespread development of Internet networks, the growth of bandwidth have significantly increased the availability of remote data processing centers for various kinds of computing. This later led to a boom in cloud services, including a render farm for rendering computer graphics.

Online render farm

An online render farm is an ideal solution for individual freelancers and studios who need access to significant on-demand render power. The time to load the initial data and render is multiple times less to render on your computer and even on several studio computers. For large resolutions, even sending static frame to the farm makes sense – rendering of one image can go in a distributed mode using a significant number of servers.

Eventually, time is always money, and with the help of render farms, you can save a lot of this time. In addition, using a farm or even a studio saves you from the following problems:

• The need to invest significant resources in a server room
• The need to buy, renew, and distribute an additional number of software licenses
• Solving problems with hardware
• The need to buy new components and servers every 3-5 years
• To solve the problem of equipment downtime when there is no need for a farm, but hardware needs to be maintained and it consumes electricity a lot, too.

Typically, render services provide their software in the form of various plugins to install on your graphics package, which allows you to use the farm's remote facilities as just another tool built into the normal production pipeline.

Like any graphics tool, however, sending tasks to a render farm is not a magic wand and needs to be used wisely. Otherwise, you can find yourself in a situation where you have a bunch of incorrectly rendered frames on hand, and the money has already burned out, and there is no fault of the render farm in this.

As you know, with one ax you can build a house and cut off your hand. Therefore, it is important to understand how and why to use the render farm tool, and I will help you figure it out in order to avoid common mistakes and understand how to use farm resources efficiently to your maximum benefit.

How to estimate the cost of a render farm

The question is very important, monetary and frequent, but ... It is important to understand that at the moment there are NO ways to correctly and with acceptable accuracy estimate, predict, predict the rendering time of a scene without making this same render partially or completely. So, let's go!

No, seriously. In any software, given the infinite number of parameters and settings, the variability of materials, textures, lighting, and external plugins, it is impossible to predict the render time without doing this same render. IT giants like Google have been working on a solution to this problem for a long time, but even with their resources, the help of software developers, and a lot of accumulated data, there is simply no good solution, at least a public one.

However, an approximate, rough estimate can be obtained. Each render farm has a measurable unit of performance, based on which the price is calculated in the future. It can be the cost of rendering on one server for 1 hour, Gigahertz of power per hour, or something similar. Based on this information, you can compare farm prices with each other and roughly estimate the cost of rendering your project. All render farms have cost calculators that will help you calculate the cost of a render before you start using the service.

Render Cost Calculators

Render farms cannot predict render costs based only on animation duration, number of frames and resolution, or polygon count. As mentioned above, this is still a utopia.

Render cost calculators use a similar method and it's quite simple. They make a comparison of the performance of the farm server relative to your computer. The resulting ratio is applied to the average render time on your computer, multiplied by the number of frames and the cost per unit of performance on the farm.

Let's look at the example of the render cost calculator of the largest render farm – Rebus Farm.

First of all, we see a warning in the calculator that the calculator makes only an approximate estimate and for a more accurate prediction of the scene rendering time, it is recommended to make several test frames on the farm.

Next, we select a CPU or GPU render (Octane, Redshift), we will render an animation or a static image and the frame render time on YOUR computer – I set the animation, 100 frames, 60 minutes per frame.

Then you need to enter information about YOUR computer on which such a render time was obtained. I choose i7-8700K.

We get a calculation. 1 GHz / hour on Rebus currently costs 86 pennies, and in order to fully render the project with the given parameters, 6700 rubles or 93 euros. A lot on the one hand, but it turns out that my render would take 4+ days of non-stop operation of the computer, and here I can get results in 30-60 minutes somewhere. Do not forget that I still need to continue working on projects; I can’t go into the render phase for 4 days and forget about everything else.

The price for rendering varies from service to service and depends on tariff plans and priorities. Most render farms offer significant discounts or bonus packages when topping up a significant amount. As a rule, an additional benefit is offered not in the form of a discount on the cost of a service package, but through the accrual of additional bonuses to the amount of purchased.

What are the time costs when working with a render farm

• Total project rendering time - depends on the size, complexity, and, ultimately, the rendering time of each frame on the server
• Waiting time in the queue - depends on the priority/tariff plan, the workload of the entire render farm, as well as the presence or absence of a queue of tasks ahead of you
• The number of dedicated nodes for your tasks - is determined by the availability of resources and your tariff plan, too. As a rule, render farms try to direct maximum resources to tasks if there are free servers
• Technical problems - sometimes manual intervention of render farm specialists is required for the correct result, so the time here depends on the type of circumstances and the speed of response of service support

As noted earlier, cost calculators on render farms are a tool for a quick, but a very rough estimate of rendering costs and the figures obtained should be treated as an approximate order of cost, which can easily differ from the real cost even on a small sequence by 20-30- 40% both ways.

The cost calculator does not take into account the time spent on opening the scene, the time it takes to calculate global illumination, and many other nuances. That is why all render farms have a warning next to the calculator that the estimate is very rough and no one is responsible for the accuracy.

Let's take a closer look at the options for using cloud resources for rendering and their pros and cons.

Cloud Use Options

Online rendering services use clusters of fairly fast servers that have a high-speed Internet connection. Server processors are quite modern, usually Intel Xeon, but, of course, not the most expensive and productive models. The power and efficiency of a render farm lie in its scalability and the ability to distribute calculations across a large number of servers. If you have a top-end i9 processor or Ryzen Threadripper, then it is quite possible that your computer may be faster than a regular server on a render farm

However, the point is that the farm can easily allocate 50-100-200 or more servers for your animation!

In the cloud, you have the following options for resource usage:

The usage of a cloud render service (render farm), which makes it easy to send your frames for rendering on a large number of servers. This option assumes a significant (depending on the farm, of course) degree of process automation; in addition, the service bears the cost of data storage, and the required number of licenses for software on its equipment. It turns out a comprehensive service on the principle of "all-inclusive", where you pay only for the rendering time without any commissions, additional payments for software, support, data transfer, etc.

Turn to cooperative rendering services, where each “server” is someone’s personal computer and its owner voluntarily provides its resources for free for a while to render other people’s projects, and then you have to compensate the community for the resources spent by providing your computer according to the same model.

Classic server rental involves getting access to a powerful server where you can work and / or render as on your work computer. Infrastructure as a service (IaaS) is a general model of cloud providers that allows you to independently configure the necessary infrastructure for yourself: allocate the necessary number of servers of the required performance, take the necessary storage, etc.

Issues of administration of this infrastructure, software configuration, and its licensing when this is left to you.

Each option has its advantages and disadvantages:

Render farms

• On-demand service, pay only for productive render without additional fees
• Rendering on a large number of servers
• Usually involves a good level of automation of all processes
• As a rule, farms offer their plugins for various software (3ds Max, C4D, Maya, Houdini, etc.), which will collect the necessary scene files for you, send them to the farm, and download ready-made frames
• Simple and clear project tracking, cost control

Cooperative rendering

• It's free (if you do not take into account that you will need to provide your computer, as well)
• The whole thing is driven by a community of enthusiasts
• No data protection
• You can not predict the time of rendering readiness
• If we use something non-standard in the scene, there will be problems
• No guarantees that the hardware of individual users will be suitable for the project (for example, in terms of RAM)

Server rental

• Manual setting
• The ability to edit, and render the project at your discretion
• Any tests/edits without the need to re-upload the project to the server
• The ability to monitor rendering statistics in real time, look into the frame buffer
• No queuing, only exclusive use
• Potentially fewer errors due to lack of render farm scripts
• You can render on rare software, with self-written shaders, etc.

Rent of virtual architecture in the cloud for rendering

• Manual setting
• The ability to edit, and render the project at your discretion
• Any tests/edits without the need to re-upload the project to the server
• The ability to monitor rendering statistics in real time, look into the frame buffer
• No queuing, only exclusive use
• Potentially fewer errors due to lack of render farm scripts
• You can render on rare software, with self-written shaders, etc.

The main steps when working with render farms:

Stage preparation and loading

At the first stage, you need to get rid of the absolute dependencies in the scene and replace them with relative ones. This applies, for example, to paths for external assets: the environment on the farm is different from the structure on your computer, and even more so from the environment in your studio. Most of the special render farm plugins, when sending the project to the farm, will kill these paths for you and make the necessary changes so that when rendering all the assets are found and pulled up correctly. Some services with a low level of automation simply provide users with instructions on how to build a project for rendering, pack it into an archive and upload it manually.

After such preparation, the scene is uploaded by the software to the farm (some farms also support uploading via FTP clients and even a web interface).

Rendering and task management

After downloading and running your project is sent to a certain number of servers using the render manager. Each of the servers takes a certain amount of time to open your scene. The time significantly depends on the size and complexity of the project, and even despite the powerful internal network between the data warehouse and the servers, it lasts from a few seconds to several minutes. Each of the servers, depending on your project, launches the necessary software and opens your scene in it. You have probably noticed how long sometimes heavy scenes open on your computer. In addition to complexity, the opening time also depends on the software itself - somewhere faster, somewhere slower.

The time to open the scene is not taken into account when calculating the cost calculator but is charged in the future. Usually, everyone takes only the pure render time for calculations, forgetting about the opening time of the scene. It is important to note that each render farm has a different data center, and even if the hardware configurations are identical, there will always be deviations in render time, both positive and negative.

At this stage, you can track the rendering progress through your personal account or special software (in some cases, farms even have mobile applications), and change the tariff plan if necessary. At the end of the render or if errors occur, as a rule, render farms send you a notification.

Downloading ready-made frames

When the frames are rendered, they can be downloaded via FTP, web interface, or special software. The latter usually syncs frames as it's ready and you don't need to download a large archive after the render is complete.

At what to pay attention when working with render farms

As you understand, all stages of working with online services are quite simple and short, especially if the farm has its software for automating processes. Specialized software simply puts the project from your pipeline with minimal edits into the render farm environment and renders. Under the hood, the software hides a lot of complex decisions to simplify the interaction as much as possible, but you need to understand that the environment in which the scene will be rendered on the farm is always different from the one in which you originally created it.

It is clear that the main goal of a render farm is to save you time, but at the same time, this is a rather complex hardware and software complex and technically complex service, so it is always better to test, clarify and check several points before going to the final render.

It’s always a good idea to take the time to render a test frame in the scene, even if the scene isn't finished yet. In this way, it will be possible to identify potential problems - for example, compatibility of software, and plugins, and then you will have a reserve of time to make changes or to clarify the nuances with farm support. Of course, this does not negate the need for a test render already in the final scene.

It is important to get to know one or more render farms in advance, without a hard deadline behind you, so that you have time to calmly figure it out. The advantages of this approach are obvious:

• Relaxed familiarization with the features and tools of the render farm
• Ability to test internet transfer speed to and from the farm
• Clarify the possibility of supporting specific software or plug-ins with support, ask questions about working with the farm
• Check if your projects render correctly on the farm. For these purposes, you can render a couple of frames from an already delivered project and compare the frames from the farm with yours.

Assets from the Internet (missing paths, wrong shaders)

Separately, it is worth warning to use assets downloaded from the Internet with caution, because sometimes they create problems when rendering. Professional online model stores like Evermotion offer great models that are 100% ready to render, but if you download models from various obscure sources, the models may have empty paths or links to shaders from other render engines, which guarantees incorrect rendering in the future. You need to check that the models do not refer to missing textures or shaders from other renderers

Checking supported software

On any render farm, you can find a list of software that the service supports, including major graphics packages, render engines, and third-party plugins. However, taking into account how wide the range of software for creating and rendering computer graphics is, how many plugins there are, different versions of the same software, etc. - it's better to double-check and make sure that your software is among the supported ones, and then, especially in case of minimal doubt, write to support for clarification.

Let's skip significant differences in the version, for example, 3ds Max 2021 and 3ds Max 2022, but even differences in one digit of a small plugin can serve as a source of problems in the future. Later versions of the software are not always compatible with the previous ones, and it may turn out that you are using some kind of ancient or generally experimental build of some plugin. In short, it is better to clarify and find out!

In some cases, render farms can help update or, on the contrary, lower the version of individual software on some parts of the servers to correctly render your project, but you need to talk and agree. And a test render will not hurt, as always.

Main features of render farms

Before choosing a render farm and starting the render, I recommend paying attention to the features of the work, and sometimes it’s even worth reading the user agreement during registration. Here are a few highlights to keep in mind:

• Data storage on the render farm does not provide for long periods. Usually, after some time after rendering (from a couple of days to several weeks), your projects and results will be deleted. It is important to clarify the data storage period, whether there are volume limits and whether there are any additional payments for space.
• The funds on the account of the online service are usually valid indefinitely, but some farms may reset the balance after some time. Better to clarify.
• The refund policy varies from farm to farm, but in my experience, more often than not, render farms do not refund funds after purchasing credits and replenishing the account.
• The rules for using credits and bonus funds for testing the service also differ significantly, but, usually, when registering, the service credits you with a certain amount of funds for free, and you can only spend on test frames. Such footage will be watermarked and/or taken at a lower resolution.
• All online services work 24/365, ideally, technical support should also be around the clock.

Non-disclosure agreement

Like any cloud service, render farms take significant measures to protect user data and a non-disclosure agreement is an important part of the user agreement. If you need additional guarantees, you can request a separate farm agreement.

Discounts on render farms

If you are going to render a large project or use a particular service all the time, it will be useful to study in detail the discounts for one-time large top-ups and the policy of special promotions and offers. All that is saved is earned!

Conclusions:

The first experience with render farms can be quite controversial. There are many different services, with different approaches and tools, and it takes time to look at, test, and understand them. And only then will convenience, simplicity and time savings come.

First of all, you need to check whether your software is supported, and what prices the farm has. You can compare several farms on calculators, but many factors that affect the real cost will still be missed. In any preliminary estimates and forecasts, I advise you to lay an additional 20-30% boldly.

It's a good idea to do tests not only with the final versions of the scene, but also in the process of work. This will help to learn about possible problems early, fix them and avoid them in the future. As a result, this will greatly facilitate the final phase of the final renders, when the deadline presses and the degree of tension grows.