What's up with Vray Lens Effect?

[yyk]

Here's a quick noisy render saved from VFB:



After rendering I enabled Vray Lens Effect and nothing happens. I tick "Bloom" and "Glare" and nothing happens. I then tick "Interactive" and Max starts rendering the scene again which is not what I wanted and could ruin a deadline had this been a final render that I had not saved and just presumed the Lens Effect works as a post effect you can just turn on after rendering.

After a minute the rendering is complete and I'm greeted with the same exact result I started with - no hint of any bloom or glare. I play with Bloom Weight and Size and nothing happens, same with Glare. I then find the LensEffectsSource element from VFB and switch to it, which results in a very burnt out version of my initial rendering so I switch back to RGB which, in turn, results in a completely white image. I figure the Lens Effect is finally doing something, namely, burning the whole image, so I tick Bloom and Glare off and VFB remains completely white. Next thing that comes to mind is to turn down the image exposure via VFB Color corrections and fair enough, turning it down results in this:



Which is an improvement I guess because now there is a certain bloom present. The downside is judging from the image I now seem to have gamma at around 1 which is an unexpected result. At this point it's no surprise ticking Bloom & Glare off does absolutely nothing to remove the effects, let alone correct my gamma to the point where it was in the original rendering.

I usually do all the bloom stuff in post but I'm curious to know what I'm doing wrong here?

EDIT: I have no idea why that third image insists on staying here

[PIXELBOX_SRO]

check out Alfa Smyrna (Pixela) tutorial on how to do this properly.
there seems to be EXACT way of pressing things.

Chaosgroup:
this sort of post has been here very often. Why not put the correct workflow into the tutorials in vray "manual"??

[PIXELBOX_SRO]

http://pixela-3d.com/blog/tutorials/vray-lens-effects

[voltron7]

Hi yyk,

I have also had similar issues with that effect that remain unresolved. Seems to work on some scenes right away, while others it behaves as you've described.
seems to do nothing with masks enabled, and total blowout with masks disabled.
I can't figure it out, but when it works, it is great, but seems really hard to get consistency between similar or very similar scenes. It also is more annoying to use without the GUI in the vfb. (more steps, clicking, and moving around open windows in my max screen.)

That tutorial is helpful, but even so, the effect seems really quirky.
Must agree with others that there should be better and more documentation/tutorial on the help page...

[yyk]

Thanks for the replies guys. Martin, I've seen Pixelas tutorial before and just to be sure I tried following it again. I remember a scene I tried it with and it worked, but this time around following the steps results in the very same behaviour I described in the original post. Namely, after updating the scene, ticking Bloom and Glare on and updating the effect nothing happens. I've played with the sliders and there is no response whatsoever.. like Voltron said, it seems to vary depending on the scene.

I'm not only trying to find out a proper workflow with this but also to point out that the effect which has been around for years is far from easy to use. It really shouldn't need a tutorial to work with.

[Svetlozar Draganov]

After rendering I enabled Vray Lens Effect and nothing happens. I tick "Bloom" and "Glare" and nothing happens. I then tick "Interactive" and Max starts rendering the scene again:

Lens Effects are Post Effects -this is true , but you need to turn them ON before the rendering , not after that.
This is necessary because Lens Effects are generated with e separate Render Element - and this element must be calculated as every other render element > that's why if you have already calculated image with Lens Effects OFF and you want to turn them ON Vray needs to calculate the image again in order to render Lens Effects Render Element.

Please send your scene to vray@chaosgroup.com and we will investigate what cause this burning.

[Slazzo]

I find very uncomfortable working with Lens Effects, sometimes in Interactive mode when playing with sliders after few moves starts to re-render the image.

I think this kind of staff should be programmed in a standalone frame buffer, that could enhance the image in more advanced way.

This will work as example: http://www.scriptspot.com/3ds-max/sc...x-frame-buffer

To shame after 10 years this kind of things wasn't done or done but in more like a lazy-way, and seems that if nobody asks for something then not much is improved. Don't get me wrong, I'm a very V-Ray fan!

[Svetlozar Draganov]

Thank you very much for your feedback.

If you still have troubles with Vray Lens Effects - it would be very useful for us if you send us your scene along with step by step instructions how to reproduce the issue you are facing.

Thank you very much in advance.

[voltron7]

I can't send a scene, but there is nothing unusual in the scenes...very simple.
My biggest issue with VRLA is that I might get it just right in one interior scene. Then, I have another interior scene, basically the same as the last one, but just slightly different layout of room.
I apply the VRLA with identical settings and often the effect does nothing you could visually perceive. Same lighting, same GI settings, same units, many/most same materials and same lens effect settings seems like it should
produce similar results, or at least close enough to use as a starting point.
I know that it will be different in each scene, etc, but it seems that it either works, or does apparently nothing. So I am guessing something is making the effect incredibly weak, or incredibly strong and seems to have no relation to phys cam settings, scene units, light multipliers so I am at a loss for the cause. again, they are really nice if they work, but it seems like a hit or miss workflow ATM. Also I prefer the lens effects button in the vfb rather than going through the "rendering--->effects" menu. Surely you are busy, but maybe chaosgroup could/should put up a couple of example scenes, maybe a few of different types (arch viz interior, arch viz exterior, product studio, etc.) Might be helpful in figuring the problem out...? Take itoo for example...great documentation and example scenes, too.

[yyk]

Lens Effects are Post Effects -this is true , but you need to turn them ON before the rendering , not after that.
This is necessary because Lens Effects are generated with e separate Render Element - and this element must be calculated as every other render element > that's why if you have already calculated image with Lens Effects OFF and you want to turn them ON Vray needs to calculate the image again in order to render Lens Effects Render Element.

Please send your scene to vray@chaosgroup.com and we will investigate what cause this burning.

Thanks for the reply. I will try to send you a simple scene with the problem early next week!

[fraggle]

+1 for me. It can work on a scene, then later on it will not work anymore.
"Interactive" is a joke because the scene keep rendering again just by moving the slider.
I notice that it faield less on very small scene size than bigger one.

fraggle