Question Updating RenderTarget Texture ID from Native engine

Iam new to Unity and can you help me with some tips on how to design the following application?

1) Unity uses DirectX backend and we use another Native Library to render on RenderTarget.

2) Native Library returns Texture ID after rendering on RenderTarget.

3) I need to use this ID to display image on the main Unity application.

I see applications where we create materials and add Images to it and use them script / shaders.
In my application initially there will be a solid plain window (say white) and later the RenderTarget Id given by Native engine should be used as Texture and just needs to be texture mapped.

Do i need to write HLSL shader and/or script to handle this.

If i need to write shaders how do i update the texture id before the call to SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, IN.uv);

Please let me know, thanks in advance.

Venkat

 

Take a look at
https://docs.unity3d.com/ScriptReference/Texture2D.CreateExternalTexture.html

You don't need to write a custom shader but you do need to write a C# script (assuming that your native library already provides the texture id to C#)

 

Thank you for your reply.

I tried this earlier but for some reason, this doesn't seem to work.

I get texture ID from the native engine and assign it to createExternalTexture(), I don't see the O/P.
I tried writing a simple OpenGL application that uses the same native engine and did a texture mapping with the texture ID. It works well. Only in Unity, I don't see the results.

Please check below.

############################################
Texture2D tex ;

uint OpenGLTextureID = update_demo(byteArray, Width, Height); // call to native engine which returns texture Id

tex = Texture2D.CreateExternalTexture(Width, Height, TextureFormat.RGBA32, false, true, new IntPtr(OpenGLTextureID));

GetComponent<Renderer>().material.mainTexture = tex;

Regards
Venkat

 

Looks good to me (just don't forget to destroy the material and texture in the end). I have never used it personally, though, so I'm not familiar with pitfalls.

My only guess is that update_demo and Unity are using separate OpenGL contexts and the contexts are not sharing data.

 

No they share the same Context, the native engine is initialized with Unity Context

 

Maybe try taking a RenderDoc capture with validation enabled...