New project and build same problem Major slowdown above 2K resolution

[3Dmotif]

Ok so I had this issue when I thought had been resolved at least so I though. Now I'm late on a deadline and I can't get this thing to render at the needed resolution. under 2K this scene will render at less than about 3 minutes. But if I turn the scene up to 4K the math says that it should take 4 times as long and my render time should around 15 minutes at most. ok well I have been here for 7 hours now and the pre pass is at 57% wtf! This is getting to be a constant thing with Vray for maya. Why does it not scale properly. Why do the render times change solo drastically above 2048?

Now I'm late on a deadline and I still have no finished render. at this rate I'm looking at almost 11hrs to complete the pre pass! for a 4K image! when the image at 2K render in about 3 minutes.


Vlado you guys have something very wrong with you vary for Maya on OSX builds.

[Morbid Angel]

Sorry to hear for your troubles. Without a scene it would be difficult to help trouble shoot this problem. What I can say though, is that its a common practice to calculate irradience map at lower resolution and render final result at higher. Perhaps this would be a solution for you? Also, you should keep in mind that things do not scale linearly with irradience maps in particular and in some cases a different setting all together should be used for a large frame. Lastly I can say that have you checked your memory buffer? perhaps you just run out of ram for a high res render? is your cpu at full load during a 4k render? Are you hitting the dynamic memory cap? A bit more info would be necessary to be able to help you with the issue.

[vlado]

The more probable culprit would be displacement/subdivision surfaces (including viewport subdivision, when enabled); those are tesselated to pixel-related values and when the resolution is increased, more sub-triangles are generated. In that case, increasing the dynamic memory limit, or reducing the edge length for displacement/subdivision helps a lot. V-Ray would generally print a warning when the dynamic memory limit is too low, but it may be easy to miss.

Best regards,
Vlado

[3Dmotif]

I looked and there is no displacement going on in the scene at all. And to be honest rendering doesn't take that long But the pre-pass goes up exponentially and The limits seems different. on OSX it happens over 2K where on windows it happens when I go over 4K. I have 2 very large renders that I need to do at about 16K here in the next week. I tried using David Girard's Vray tuner tile script but that really doesn't do anything for the pre pass. It still goes just as slow as the full thing was being rendered.

@Morbid Angel: I am saving all of the Irradiance map and the Lightcache out at the 4K resolution and reusing them.



I just don't understand why this can't scale properly. Not even god awful mental ray has this issue. "but yes it has many other that make it undesirable"
Just out of curiosity what is being calculated int he pre pass. I mean when you have both of your illumination methods cached to files. And I have not been getting any notifications that memory is running out.

I seriously think that there is something wrong here though as going from 1K to 2K to 4K all seem to roughly scale in time properly but as soon as you go above that it takes about 20-40 times longer than it should. This just doesn't make any sense. if you are rendering say 16x the number of pixels then it should take roughly 16x as long to process. The is no reason that I have seen thus far that justifies these increases in render times.

[vlado]

Would be best to take a look at the scene itself then. Can you send it to vraymaya@chaosgroup.com so that we can debug it? Please mention this thread specifically.

Best regards,
Vlado

[3Dmotif]

It is WAY to big to email and contains a lot of gray proxies and references. But I will see if I can put it on a FTP for you. But seeing as we have had this issue with other scenes when we try them at high resolution and the same things happens I'm inclined to think that is is something with V-ray. Perhaps it just needs a mode that forces it to scale in a linear fashion. Also it would be nice if it supported Maya's 2D pan and zoom attributes. at least then I could script in a tiled render that I could reassemble in photoshop and not have to increase the resolution in Vray.

[vlado]

But seeing as we have had this issue with other scenes when we try them at high resolution and the same things happens I'm inclined to think that is is something with V-ray.

Exactly what I'm trying to find out

Also it would be nice if it supported Maya's 2D pan and zoom attributes.

We do support the camera offset/zoom correctly from what I remember.

Best regards,
Vlado

[3Dmotif]

We tried enabling it in 2014 and it has no effect. Vray just renders as though it is just ignoring it.

On another topic how come the OSX version of Vray for maya is missing all of the DR options that appear in the windows version. OSX only has an enable/disble checkbox where the windows version has about half a dozen features that you can toggle.

[Dariusz Makowski (Dadal)]

We tried enabling it in 2014 and it has no effect. Vray just renders as though it is just ignoring it.

On another topic how come the OSX version of Vray for maya is missing all of the DR options that appear in the windows version. OSX only has an enable/disble checkbox where the windows version has about half a dozen features that you can toggle.

Are you sure you are running nightly on OSX? Because u need nightly for that.

Regarding scene most of it should scale linearly but if u have GI/Displacement/and other view depended features then that will NOT scale linearly and you need to readjust ur settings. I believe its ur GI that was too high and you need to adjust that in order to render it fast.

[3Dmotif]

well the GI is set to medium and the irradiance and the LC are both being read from file. and as I said before there is no displacement in the scene at all.

[t.petrov]

We do support the camera offset/zoom correctly from what I remember.

I think this is different from the ones available as tools in the viewport.
We do support pan&zoom, but it is available in the 3.0 builds

[Svetlozar Draganov]

It is WAY to big to email and contains a lot of gray proxies and references. But I will see if I can put it on a FTP for you. But seeing as we have had this issue with other scenes when we try them at high resolution and the same things happens I'm inclined to think that is is something with V-ray. Perhaps it just needs a mode that forces it to scale in a linear fashion. Also it would be nice if it supported Maya's 2D pan and zoom attributes. at least then I could script in a tiled render that I could reassemble in photoshop and not have to increase the resolution in Vray.

We could provide our FTP if needed - just let us know at vraymaya@chaosgroup.com