I have prob with RPC and vray 15 RC3 - Max 9 -64 bits.
I’m using vray sun + skylight + physCam.
All my rpc are very very dark. I try to include/exclude to GI. Include in vray sun, rpc are all in 100% illumination. but they are always darK. I try too render only one in isolate selection and another vrayPhysCam and when i start rendering, Rendering windows stay with the message ‘Preparing tone operator’ and nothing… Impossible to cancel rendering. I must restart max.
has the rpc plugin been released for max 9?
Of course… one week before release of max 9. receive link to download from archvision by e-mail.
You can download here. Now it’s free. 
The prob comes from exposure from the Vray Physical Camera. When i turn it off rpc are fines. So i will render in 2 pass but if another way exist to render in only one pass…
Resolved.
1. In Vray Sun, rpc are excluded by default, include all.
2. Put illumation of rpc in Mass Edit for each between 0 to 25, seems to be the inverse. For a tree in 75 by default put it in 100-75=25.