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Hello this is a tutorial to use Open CV on Unity-Windows with the use of Emgu CV.
This is open source for open source but for commercial uses you'll need to purchase licenses, for more details see : https://www.emgu.com/wiki/index.php/Licensing:#A_Quick_Overview
then you can copy the /Plugins directory above and put it in your Unity's /Assets/ directory
Or build it step by step see below (skip to Test otherwise)
On this link https://github.com/emgucv/emgucv/releases
Go find the release 4.9.0 (latest currently) download "libemgucv-windesktop-4.9.0.5494.zip"
<img src="screenshots/emgucv_release_4_9_0.png" width="550">
Unzip it and go into \libs
Make a directory anywhere called Plugins (It'll go in your unity project later)
Copy all the dynamic link library ( .dll) here into Plugins.
Now go into \libs\runtimes\win-x64\native (change win-x64 if you're not in 64 bit)
<img src="screenshots/libemgucv_libs_native.png" width="550">
And again copy all the dynamic link library ( .dll) here into Plugins.
I didn't test in all version but it worked in my 2021 version's project
I'm using 2022.3.37f1 version here. We'll start from a blank 3D project (if you can't make it work in your project you can create a blank project quickly and try)
In Assets we will (create a Scripts directory for later and )
copy the Plugins directory. You will have a lot of Dependencies issues :
<img src="screenshots/erreur_drag_plugins.PNG" width="550">
We'll need to go on www.nuget.org and download those dependencies :
Here I need System.Text.Json , (PresentationCore) , System.Drawing.Common , Microsoft.VisualStudio.DebuggerVisualizers
First download the nupkg and extract it (same as downlading a .zip and unzip)
Then inside we go to lib/netstandard2.0 and copy the .dll to Plugins
We keep downloading until all dependencies are resolved (note that some dependencies will have dependencies of their own).
I deleted Emgu.CV.Wpf in Plugins because I couldn't find his dependencies PresentationCore properly.
It's a minor part of EmguCv we should still be able to use the majority of it.
Wether you downloaded my /Plugins/ directory or built it step by step, we can now make a few test.
(We'll add a ball and a move script to have something to look at in our blank project see [Scripts/move.cs](Scripts/move.cs))
a real time recording feature see [Scripts/Recorder](Scripts/Recorder.cs).
Place the script on a gameobject and link it the camera you want to record.
There is a colorConversion because OpenCv is in BGR while Unity is in RGB.
And a Flip because OpenCv places the origin on the top left of images and Unity in the bottom left (=> going up means an increasing Y_coordinate in Unity but decreasing in Open_Cv)
The script can extend frames duration be sure to use Time.deltaTime in your scripts when needed.
If you have performance issue try recording in .avi format instead of .mp4 (comment/uncomment appropriate lines).
Note that the path by default ( Assets/output.avi ) will only be useful in the editor as /Assets is inaccessible once built.
You can use "Application.persistentDataPath" for a consistent way to read/write outside your Unity Application.