Update readme.md

Author: julienkay

readme.md

@@ -1,5 +1,5 @@
 > **Warning**
-> !! Work in progress !!  
+> **!!! Work in progress !!!**  
 > Does not work, but could be fun to fix.
 
 # MERF Unity Viewer
@@ -9,6 +9,10 @@ Real-time View Synthesis in Unbounded Scenes](https://creiser.github.io/merf/)[^
 
 *Please note, that this is an unofficial port. I am not affiliated with the original authors or their institution.*
 
+## Known Issues
+
+- Everything mostly works up to calculating the diffuse term of the volume. But the *'evaluateNetwork()'* function in the shader seems to return unreasonably high values, probably due to some coordinate space or other platform-specific differences between the original Three.js viewer and Unity. Contributions welcome.
+
 ## Acknowledgements
 
 [^1]: [Christian Reiser and Richard Szeliski and Dor Verbin and Pratul P. Srinivasan and Ben Mildenhall and Andreas Geiger and Jonathan T. Barron and Peter Hedman. MERF: Memory-Efficient Radiance Fields for Real-time View Synthesis in Unbounded Scenes. SIGGRAPH, 2023](https://creiser.github.io/merf/)