C4D output system file size vs V-Ray output system file size issues

[akos_kiss]

Hi All!

We've done some test using the c4d default output system and the vray output system and noticed an interesting thing.

I've attached the simple scene file with 3 spheres. The render settings are simple, the main difference is that one uses the Picture viewer to save the file and the other uses the vray output system. The format is exr 32 bit with DWAB compression for both settings.

There is a 10+x difference between the files if i render from the picture viewer vs the vfb with vray output system. the PV one is 106 875 KB and the vfb one is 7333 KB. I cant figure out what is causing this issue. Anyone ran into this?
Don't get my wrong i take the vray output systems smaller file any day, but i just don't understand what kind of data is in the one from the picture viewer...

I've put both of them in difference mode in after effects and if i crank the viewport expo up i can se some difference, but i don't know what cases this. I tried with the Animated Noise Pattern turned on and off and the difference was the same or similar. it looks like there is some difference in some areas. Any ide why is there a difference?

C4D File and exr renders.

[aleksandar.kasabov]

Hello akos_kiss,

The difference in the file size comes from the naming of the EXR channels.

For example: in the V-Ray output, the channels for the "Caustics" render element are named "Caustics.R", "Caustics.G", and "Caustics.B", while the EXR from the native Cinema4D system has channels with names "Caustics.red", "Caustics.green" and "Caustics.blue". That means that the way Cinema4D saves openEXR files is the reason for this difference. I hope this is of help.

[akos_kiss]

Hi aleksandar.kasabov,

If i understand this correctly The way c4d's native system does the naming of the channels results in the file size to go from 7 MB to over 100mb? This is hilarious

[aleksandar.kasabov]

Actually, the OpenEXR library is written in a way that when there is a DWA compression, it is actually applied only for RGBA information. All other channels are compressed with RLE compression, including the old EXR names for RGBA- .red, .green., .blue and .alpha. I hope this makes sense.