I´ve been using Vray for a number of years, but this is the strangest issue I´ve encountered yet. Take a look at the images, and pardon the lighting conditions - I´m in the middel of testing this issue:
This is where the strange thing happens - the ONLY thing that is changed here is that the door is open enough that its possible to see its backside, and the whole exposure goes to shit.
On the last picture nothing in the scene is changed whatsoever. I just moved the perspective viewport enough so that the doors backside isn´t visible anymore, and the whole thing goes back to normal.
All the pictures are in perspective viewport
The first and second image is an animation on the door while the perspective viewport stays the same. From the second to the third image the perspective viewport is slightly changed, while the door doesn´t move.
Please note that although I´ve tested different exposure settings, cameras etc, I´ve narrowed the issue down to wether I can see the backside of the door or not. Everything stays the same, but if I change the camera or perspective just enought to see the backside of the door (even if its just a few cm change of camera position) the exposure changes radically.
The door is normal, just like any other geometric part. It has a properly built backside, so its not the backside of polygons. I´ve also tried to collapse the stack, to no avail. Does anyone have any idea of whats happening here? I´m kinda lost, and have no idea why it happens. Although its a couple of years since I used Vray last time, I´m a pretty experienced Vray\3dsmax user.
100% positive, yes. The ONLY thing that changed between the second and third image is that I moved the perspective viewport just enough to not reveal the backside of the door. Believe me, I tried many times too, because the problem is just too weird …
Before I figured out that the door was the reason, I went through all the normal assumtions like changing exposure, changing camera settings, collapsing the stack etc. At first I thought it was some new auto exposure thing that was implemented since the last time I used Vray
Did another test now, just to see if anything magically fixed itself after a complete restart. But unfortunately no :(.
The only thing I did (again) was to move the perspective viewport just enough to reveal the inside of the door or not, and the whole exposure changes. This is by far the strangest problem I´ve encountered in Vray
(Btw: The renders below are done with different lights than the first renders.)
Each camera has its own set of lights. The camera and its corresponding lights are in layers named "Seq_xx)
You can use whatever set of lights, just hide the other Seq-layers.
In the layer ctrl you will find animation controls. Use these to open the right-side door.
Use the viewport or camera to alternate between seeing the inside of the door and not, and see how the exposure changes
Sorry, a bit of misunderstanding there. I tried with auto exposure both on and off, but the problem persisted. And even if its on, it shouldn´t react like that. But anyway, are you saying you have it fixed?
I turned off Auto Exposure in the Render Settings > Camera. I selected CAM02, set the EV to about 3. (Aslo tried regular PhysCam and Physical Camera Exposure). Rotated the door all the way open with the controls and no problems. Exposure stays the same all the time.
Without a Cam though (just in perspective) everything has a huge DOF or blur. Very strange, but when I uncheck Camera Motion Blur in the render settings, it’s gone, and when I enable it again, it stays off not to come back…
Its been a while since I used Vray, and this auto exposure in render settings was new to me. Its probably been there for a while, but I can´t remember it. (I talked about exposure control in environment and effects.) Turning it off fixed several issues for me.
Anyway, thanks for the help Vizionen. While it was a small thing, you really helped me out
