Falcor Missing Parts

Hi, I’m trying to build https://github.com/league1991/RTCaustics project,

In project instruction it said :
To build the demo, one should take the following steps:

Download NVIDIA falcor 3.1
Make a folder called "Caustics" under \Source\Samples\Raytracing
Checkout the repo under the "Caustics" folder
Copy content under "Source\Samples\Raytracing\Caustics\Media" folder to "Media" folder under falcor root directory.
Add "Caustics.vcxproj" to falcor solution
Build falcor with caustics project

So I did, I downloaded falcor 3.1.0 from github and built it, it was working fine, but when I add caustic project, it’s very confusing.
It seems developer mixed two different versions of falcor for their craft, for example their source contains IRenderer which is presented in newer falcor and not in the 3.1, They used RtScene, StructuredBuffer, RtState which only exists in falcor 3.X, They used RasterScenePass which is only in falcor 4.X+

I’m completely confused, anybody knows how to deal with the following issue?


Hello @thegpuguy and welcome to the NVIDIA developer forums!

Falcor is already on version 5.1, did you try and contact the owner of the RTCaustics github project to update his dependencies and instructions to a newer version?

Beyond this I am afraid i can’t help much, but maybe someone in the dev community has faced a similar issue?

Thank you!

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Thank you for warm welcome!
I informed developer both in email and as github issues, He hasn’t been active almost for a year, Now he works at Nvidia I’m not sure if I can reach to him, I will be thankful if someone at Nvidia can inform him about the issue, it’s a very useful repo.

Thank you

Oh I didn’t know that the person works at NVIDIA. I can make no promises, but I will see if I can find him.

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Thank you so much!
Person name is Yiubun Auyeung and it seems he is the man behind the Unreal Engine 4 caustic system.
I hope he update the repo to latest Falcor soon.

Hi, I am the author of the repo. Now I am migrating the code to the latest falcor. It’s not an easy task because lots of stuff has to be changed. I will teel you when I am done.

You can also checkout yaobin/falcor5.1 to see the progress.


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Thank you so much, I waited for this so long. Is there anything I can help you with let me know!

Is there any chance that you add the dispersion like unreal engine to falcor version?

Thanks again!


I am sorry to tell you that I still cannot recover the project because the falcor code is so different from what it was.

I suggest using the ue4 repo, in addition to my repo’s main funtionality, it also contains dispersion and supports various light sources. You can start from this file:

On the other hand, I did make some progress on the falcor demo. I can compile the project with falcor 5.1, though it still cannot initialize the scene and shaders and I have no confidence when I can fix all the errors. You can check out the “yaobin/Falcor5.1” branch if you like.

Hopefully that can help. If you have any question, just leave the message here, or send an email to me. My email address is yaobino@nvidia.com.