This manual details Blendy VJ operation step by step, meant to be used as reference.

If you want to get started quickly, watch the tutorials.




1. Installation



1.1 System Requirements

You need Mac computer with OSX 10.6.8 or higher. A Macbook Pro or Mac Pro is recommended.

It can be used with a Matrox TrippleHead2Go or DualHead2Go, and/or with multiple video outputs.


1.2 Fresh Install

Download Blendy VJ, open the dmg package and drag Blendy to your Applications folder, or any folder you want.


1.3 Upgrade from beta version

Do not upgrade your current work if you are not online. If there’s any problem, you will have to reauthorize the beta again.

If you are using MadMapper, you may have to open it and re-select Blendy VJ as it’s Source.  This is correct some strange behavior Blendy VJ beta was having with MadMapper saved projects.

Once you start the latest Blendy VJ for the first time, it will update the licence info on your computer and the beta will stop working. This is done to better secure your licence info. You can still use the beta version if you want, just open it and Authorize from it again.

The location and format of the default project file has changed. Blendy VJ will still read automatically the Blendy VJ.blendy file if it is located on the same folder as your app. So it is recommended that you save (CMD+S) your project after you open it for the first time. Then you can delete the Blendy VJ.blendy file. More details on the FILE section.


1.4 Authorization

Blendy VJ can be tried for free, but with a vertical watermark in the middle of the blend. To remove the watermark, you need to buy a licence. Licence types and prices are on the download page. You will receive your serial once we get the payment confirmation. Each licence can be installed on 2 computers.

Once you have your serial, open Blendy VJ, go to BLENDY VJ DEMO tab and click Authorize. Your default browser will open on Blendy’s  authorization system. Fill the registration, and then you  will be asked to click Authorize again on Blendy VJ. Do it!

If you want to remove Blendy VJ from one computer to use on another, open it on the computer it is authorized and click Deauthorize. Then proceed to authorize the new computer as explained above.

You can see your licence status and all authorized computers on the Licence Manager website.

Blendy VJ status

Blendy VJ status

2. How Blendy VJ works

Blendy VJ solves the problem many Vjs, artists and projectionists face when more than one projector is needed to cover an area with light. It is usually impossible to make a perfect seamless alignment of multiple projectors side by side. Either you’ll have a gap between them, doubled light, or worse.

The Problem


The solution is to overlap the projectors and fade out the edges of each one to make a seamless blend. Due to the nature of light, this fade is not a simple gradient, but a gamma curve. Blendy does all the math to get the perfect soft edge, for as many projectors as you need. All you need is to place blend strips exactly over the edges.

The Solution


Blendy VJ is a tool designed for VJs, and uses the Syphon framework to stand between any Syphon-enabled player (like Modul8 and many others) and the projection mapping tool (like MadMapper or Resolume Arena). Syphon is based on a revolutionary technology called IOSurface, available only on Mac OS X 10.6 (and above), which allows graphic applications to share textures in the graphics card, with near to zero overhead.

The simplest configuration is to use Quicktime files and MadMapper. This configuration will not allow realtime mixing and is intended for installations. Drop the Quicktime files on Blendy VJ and use MadMapper to project.

Blendy VJ + Quicktime files

For realtime mixing, you can use any Syphon enabled application/mixer (like Modul8, Resolume Avenue/Arena, VDMX, Quartz Composer, Processing, OpenFrameworks, Cinder, etc.) and MadMapper. Blendy VJ will stay between them, read the mixer’s Syphon output, combine with the blend pattern and generate a new Syphon for MadMapper, which will be used to map all the layers on the projection.

Blendy VJ + Modul8 + MadMapper

Some applications, like VDMX and Resolume Arena (not Avenue), have built-in tools for layer mapping, so they don’t need MadMapper, Blendy VJ will send only the blend pattern to the mixer, and you do the layer mapping from it.

Blendy VJ + Resolume

Blendy VJ + VDMX








3. Blendy VJ Basics

You will notice that there are very few things to setup on Blendy VJ. Basically you choose an input, blend orientation and Gamma correction. Once this is done, you can lock, minimize it, and go mix your videos.

The FILE tab

The FILE tab


Blendy VJ works with a concept of a Default Configuration. Once your setup is ready, click Save as Default on the FILE tab, or use the shortcut Command+S. After you quit Blendy VJ, the next time you open it, it will load the saved Default configuration. Load Default (shortcut Command+L), will load the last saved default configuration. On the FILE tab, the project name will be  < default >

You can also Export Config to save the current configuration to a file (shortcut Command+E), Import Config to import an exported file (shortcut Command+I), or Reset to initial factory configuration.

When there is an asterisk (*) in fron t of the current loaded project, it means that something changed on the blend and it must be saved.

Blendy VJ’s default file is stored at $HOME/Library/Application Support/Blendy VJ


4. Setting Up The Projectors

Obviously, you need multiple video outputs on your computer. Since 2012, the Macbook Pro Retina has 3 video outputs that can be used to blend up to 3 projectors. The Mac Pro usually comes with one or more video card, each with multiple outputs. You will use one for the monitor, all the others can be used for the projectors. Blendy VJ have been tested with success on a Mac Pro with 6 projectors and one monitor, but there’s really no limit.

If you do not have multiple video outputs, you will need a Matrox DualHead2GoTrippleHead2Go or similar product to output to 2 or 3 projectors. If you need to buy one, I recommend to go for the TrippleHead DP Edition. It is the most versatile, you can use adaptors to convert it’s native DisplayPort outputs to DVI, VGA or HDMI, and also works as a DualHead.

Is is important that all projectors should be the same brand and model, and their lamps have the same age for a perfect blend. Most modern projectors have the lamp hours of use information on their menu. Otherwise, you may have difference in brightness and/or contrast between them. If that happens, you need to adjust their brightness so they are as closer as possible.

Place the projectors side by side, with at least 20% of their light overlapped. If needed, you can also place the projectors vertically, making a column.

Projector Setup


The projectors’ resolution depends on your project and video cards. The simplest and flawless case is to set the projectors at 1024 x 768, totaling 2048 x 768 (2 projectors) or 3072 x 768 (3 projectors). You can use higher resolutions, of course. For full HD, set the projectors at 1920 x 1080 totaling 3840 x 1080 (2 projectors) or 5760 x 1080 (3 projectors). Anything above this, it is recommended that you first test if your video cards will support and perform well.

You can also plug 2 TrippleHead2Go on one computer to get 6 outputs. It is recommended that each TrippleHead to be plugged on separate video cards. You can plug both on the same video card or on a MacBook Pro Retina, but you will not get very high resolutions. On a MacBook Pro Retina, I could make both on 3072 x 768, but not higher. Test on your machine first!

To configure 2 TrippleHeads on the same computer, plug only one and configure it to the desired resolution. If the resolution you want is not available, open Matrox Control Panel and select it from there. Once it is ok, plug it out and plug in only the second one, configure it the same way, with the same resolution. Then plug both in and see if they go green. If not, repeat it all with a lower resolution. Once both are running, restart the computer with both plugged in and start mapping.


5. Template and Medias

When projecting or mapping anything, it is important to have a template, a blueprint of the area you will map. This template must match the resolution of your medias.

Blendy VJ has several templates available for download.

There are two ways to calculate the size of your template and media resolution, depending on what you are mapping.


5.1 Free projection

If the area of your projection is unknown, if you have freedom to project somewhere not restricted, like a big wall, the easiest is to match your media to your total output resolution. In the end, they will be scaled down a little bit, because you will not use the whole area of all projectors, since they are overlapped, but that’s not a huge problem.

Media Scaling

A 3840 x 1080 media will be scaled to fit into 2 overlapped and blended 1920 x 1080 projectors

For those basic cases, you can download templates from Blendy VJ’s TEMPLATES tab. Choose the aspect ratio, the base projector resolution and how many displays/projectors you are using. Blendy will open your default browser with the correct template. Needless to say, you must be online.

Remember, check the resolution of use this template, it must match your media! If your media was made on a different resolution, make your own template, or scale them to match the template.




Sample BLendy VJ template

Sample BLendy VJ template


5.2 Restricted Mapping

But… if you know the area of your projection, if you have to fit it in a restricted space, you need to calculate the template and media based on that area, or else it will be distorted! You will have to cover all the area with light of the projectors and when you map your media inside it, it will fit perfectly. Usually on these cases, you need to make your own template…


So, let’s take a break for some basic mapping lesson… how to make the template?

Calculate the real world height and width you want to map and find the aspect ratio by dividing width by height. Your media height will be the same as your projector’s height, and your media width will he this height multiplied by the aspect ratio.

Example: The area is 20 x 5 meters. Aspect ratio is 20/5 = 4. Projectors are 1920 x 1080. Your media will be 1080 * 4 by 1080 = 4320 x 1080.

You’re gonna need 3 projectors, the blend areas will be 720 pixels wide each. More than enough!

Zoom them out a little bit so you have some comfortable area to work with, don’t lose your time fitting them perfectly to the borders.

If the area is completely flat, your template should be something like Blendy VJ’s templates, with a grid and some circles to avoid distortion.

Now, if the area is not flat, like the facade of a building, with windows and doors, elements you probably will want to play with, take a photograph of the area you want to map and fit it inside your template proportionally. Import into Abobe Illustrator and vectorize every line and element you want to use. Use this template as a base to make all your media.

You’re gonna use the template to map, then when you change for your media, everything’s in place!

Find this interesting? Want to spend some time in Brazil learning more and drinking Catuaba? Check out our VJ University schedule….

 Now you have a template and media, it’s time to map!


6. The Input

The input is your media. Blendy VJ can use Quicktime files or Syphon server as input.

Blendy VJ will create a new Syphon server by joining the Input with the blend pattern.


6.1 Quicktime / Image Files as Input

Use Quicktime files if you do not need to mix your media. Ideally, use only on standalone installations. You will need MadMapper to do the mapping.

Blendy VJ is optimized for the HAP codec, so it is suggested to encode your media with HAP and put them on a SSD drive. Hap files are very large, if they are not on a SSD drive, there will be no throughput and performance will be worse. So if you do not have a SSD drive, use Photo-JPEG as codec.

Turn the INPUT tab ON and drop the files on Blendy VJ or click Load Movie/Image.

First drop your template to map, then drop your media to smile.

Input QuickTime / Image

Input QuickTime / Image


6.2 Syphon Server as Input

You can use any Syphon server as input to BLendy VJ. You will need MadMapper to do the mapping.

Syphon is a revolutionary technology available only for Mac OSX 10.6 and above, that enabled graphic applications to share textures. One application generates a render and publishes as a Syphon Server, Blendy VJ reads it and publish another Syphon server for MadMapper. Thanks Vade and Bangnoise for making Syphon, you both saved my life!!

There are several VJ applications that act Syphon Server, most notably Modul8, Resolume Avenue/Arena, VDMX, Mullumin, CoGe, Arkaos, and many more.

Syphon is also available as a library, so you can make your own application to act as a Syphon server with Quartz ComposerProcessing, Cinder, OpenFrameworks, Pure Data, Unity 3D, FreeFrameGL and Max. All libraries are avaliable at the Syphon website.

Input Syphon Server

Input Syphon Server

Once the Syphon server is running it will appear on Blendy VJ’s INPUT tab. Turn the INPUT tab ON, and select the Server.

All the tutorials use Modul8 as server. Despite it’s slow development cycle, I still think it is the best VJ mixer for any kind of performance.


6.3 No Input

Depending on the software you’re using, there’s no need for Input at all.

If you can live without input, do it! When Blendy VJ uses a Syphon input, it will have to duplicate it and add to it’s own Syphon server, consuming more GPU memory and power. Without Input, Blendy VJ will be light as a plume, generating a 1024 x 1024 Syphon texture, at 1 FPS. Yes, 1 frame per second!

Resolume Arena or VDMX have their own layer mapping tools, so all you need from Blendy VJ is the blend patterns that you will place abobe the projectors’ overlapped area using it’s own tools. Resolume Avenue does not have layer mapping, so it will need input.

Turn OFF the INPUT tab and watch the Resolume Tutorial or the VDMX tutorial.

If you know any other software that have layer mapping tools and could be used without Input, please tell me.


7. The Blend

Here will be discussed the main concept of blending with Blendy VJ and MadMapper. For practical examples, watch the tutorials.

You will use blendy VJ’s Syphon server as input on your mapping tool (MadMapper, Resolume or VDMX). Blendy VJ’s Syhon server is always active and running, there’s no need to turn it on.

I will explain how to blend 2 projectors horizontally using a Matrox TrippleHead2Go. Execute the same process for any additional projector. If you know how to blend projectors 1 – 2, imagine projector 2 – 3 as another 1 – 2, and so on… There’s a tutorial that shows how trivial this is.


7.1 Map the Template

Once you have light from the projectors all over your mapping area, with all the projectors are overlapping about 20% of their area making the blend areas, you will map your template tho the whole area.

This is made by creating one layer for each projector, The uv mapping (input) of each layer, must match the area. The layers will have overlapped inputs, because the projectors have overlapped areas. Make sure that the overlaps match perfectly. This is totally up to your skill, there’s no automatic way to do it, this trial and error.

The best way is to drag all the layer vertices covering all their projector’s area, and then play with the input uv mapping of each layer.


Mapping the template on MadMapper

Mapping the template on MadMapper


There is a video tutorial showing tho whole blending process in MadMapper

If you are using multiple outputs on your video card instead of a TrippleHead2Go, you will need to open multiple MadMapper instances. Watch this tutorial to see how to do that.


Mapping the template on Resolume

Mapping the template on Resolume


There is a video tutorial showing tho whole blending process in Resolume


Mapping the template on VDMX

Mapping the template on VDMX


There is a video tutorial showing tho whole blending process in VDMX


7.2 Setup Blendy VJ

Blendy VJ uses an original method of pure RGB colors to identify the blend areas of each projector.

Edit Mode: Mapping

Edit Mode: Mapping

First, all the input needs to go BLUE:


Making the template BLUE on Resolume

Making the template BLUE on Resolume



Making the template BLUE on VDMX

Making the template BLUE on VDMX



7.3 Map the Blend Stripes

Now the fun part, RGB math!


It is clear on the projection which is the overlapped area, it’s blue is doubled, it is much stronger.

We just need to addd blend stripes over this overlapped area.

Blendy VJ is outputting 2 stripes, one GREEN and one RED, because it is on EDIT MODE.


The GREEN is used on the overlapped area of the LEFT projector. When it adds to blue of the right projector, becomes a pure CYAN rectangle.


The RED is used on the overlapped area of the RIGHT projector. When it adds to blue of the left projector, it becomes a pure MAGENTA rectangle.


When both stripes are positioned on the overlapped area, perfectly one above the other, their GREEN and RED adds becoming pure YELLOW.

Mapping the blend on MadMapper

Mapping the blend on MadMapper



Mapping the blend on Resolume

Mapping the blend on Resolume



Mapping the blend on VDMX

Mapping the blend on VDMX



7.4 Adjust Gamma

If you turn EDIT MODE OFF, the GREEN and RED stripes will be replaced by the actual BLEND PATTERNS.

If your computer’s Blendy VJ is not authorized with a valid serial, you will see a big white line right in the middle of the blend. Acquire a licence and authorize tour computer to get rid of the watermark.

Light addition is not linear, so simply fading the edges does not look good, it’s needed to add some GAMMA to compensate. The best way to apply Gamma Correction is with a pure white image.

If you’re are using Blendy VJ with Input (MadMapper), you have helpers to adjust Gamma and colors.

Edit Mode: Gamma Correction

Edit Mode: Gamma Correction




If you see ano more white vertical lines, there may be some layer bleeding from it’s projector. Fine tune your mapping to get rid of it.


8. Lock And Go

Once the blend is ready, save your project and turn ON the LOCK tab. This will avoid you from touching controls that can prejudice the blend and minimize Blendy VJ’s operations to it’s basic, which is just render and publish it’s Syphon server, internally, without preview for better performance.

When locked, the only thing you can do is change the input Syphon Server and load new Quicktime files, if Input is enabled..

Locked Blendy VJ

Locked Blendy VJ