ok so i have an interior scene set up with gamma 2.2, using the vray frame buffer. im trying to add vray lens effects.
if i hit the “interactive” button to adjust the effect, it does a render, in the vfb, then opens a max frame buffer with the effect in.. however, the image is completely over exposed, before ive even enabled glare and bloom. initially the vfb keeps its original exposure, but if i minimise and restore it, or even drag another window over it, it refreshes to the over exposed look of the other fb.
i dont have this problem if i use the max frame buffer.
also, i have some issues with the dynamic range of the render i think. i have quite a contrasty scene, with a dark interior and vray sun coming through the window reflecting off some chrome.. ive deliberately darkened the wall material etc to give a strong contrast for the lens effects to work with. i dont have a clamp on the output, and the reflection of the window is pretty completely blown out on the reflective surface..
however im adjusting the settings for both glare and bloom, plus playing with the camera settings for bloom, but i cant get a good result.. either the effect is extremely subtle, or if i increase the weight, the whole image gets a blur, including the dark walls.
also trying to get a glare with rays from a saved lens effects hdr is impossible.. i can just make out some rays if i turn the weight waaaay up, but by that time the whole image is unusably blurry. compared to the result on the spot 3d page… which is super strong.. mustve had quite a multiplier on the light there.
any tricks to get control of the result?
i cant help thinking some kind of “contrast” or “balance” control to exaggerate the difference between bright and dark areas for the purposes of glre and bloom calculation would be very useful. i understand an actual “threshold” for the effect would be bad, as it would lead to highlights flickering in animation, but some more control would be good..!
just to clarify, when i do the final render it works ok, and only the “lens effects source” element has the overexposed look to it.. but when using the vfb for the interactive setup, the render on which the effects are being adjusted ends up looking like the lens effects source layer. if i set to max FB, i can set up the effect ok using interactive, then swap back to VFB for my final render.
also ive managed to get more contrast and a much more believable result by turning the sun multiplier to 5! (after calculating the gi obviously.) however this isnt ideal cos it screws with various other things, as you might imagine.
I am experiencing this as well. The lens effect appears in an over exposed 3ds Max frame buffer, and then no lens effect at all in the V-Ray frame buffer that is correctly exposed. Interact works only in 3ds Max frame buffer as well.
I’m not sure where the problem is with this (simple test cases work fine here), so for future builds we just moved the lens effects to the V-Ray VFB. In any case, if you can get us a way to reproduce this, it will be helpful.
I think I have found the issue. Its to do with the show effects/show original button. By default this is set to show original. In the 3ds Max frame buffer the effect appears with double gamma applied where is in the V-Ray frame buffer it doesn’t appear at all until you change it to show effect. Only then does the interaction/update effect work fine in the V-Ray frame buffer.
The interesting thing is if you try and change it back to show original after you have done the above, only the 3ds Max frame buffer shows the original and the V-Ray frame buffer stays the same and doesn’t show the original. I think for me there are too many controls/things to look at which make it confusing at first. The show effect/show original doesn’t need to be there IMO and having the effect appear in both the 3ds Max frame buffer and the V-Ray frame buffer at different gamma levels.