consecutive frame times very different.

[Nickh]

Hi,

We have a project which we are just trying to render now, and frame time are being very random.

a few different machines will be rendering at about 7 or 8 mins a frame, and then suddenly a machine will take 15 mins on the next frame, or even sometimes 30 or 40 mins. And its not consistent which machines do it, and happening a lot.

This is a big problem as we have 4000 frames to render, and this is massively affecting the average frame time, so I cant even accurately predict how long its going to take.

Scene is a large landscape, so there are huge amounts of trees - vray proxies being scattered with Forest pro.

Does anyone have any suggestions on this one please?

Many thanks
Nick

[Morbid Angel]

sounds like a forest pro related issue. We just did a project with few million trees in it using vray scatter and all render times were consistent.

[Nickh]

Thanks Dmitry,

so with an animation with vray scatter you see consistent frame times, when backburning frames?

I've just left an 'include maps' test going, also with irradiance map copied locally - as I have seen massive loading time issues when irradiance maps have been loaded from shared locations.

but I really dont have too time to test every permutation, so any info appreciated.

Cheers
Nick

[Morbid Angel]

curious about irradience map. Yes we had no problem on backburner. However we did not use irradience map; instead we used brute force method, which really did not slow down that much since the scene is an exterior and produced much higher quality of gi.

[vlado]

Which V-Ray version are you using?

Best regards,
Vlado

[Nickh]

Vlado, 1.5 sp3a. Any magic little check box to tick?

Morbid, could you please confirm how you use your GI for exteriors? primary & secondary brute force?

Thanks a lot

Nick

[Roest]

I think the last 4 animation projects we had the same problems. From 8 minutes to 40 even 6 hours and then 12 minutes. I can't explain..
Also very different times locally (preview tests) 8minutes and in the animation via backburner the same frame 18min?!
Nowadays we must check every 4 hours, if we're on a deadline, to look if everything is going well. Very nice in the weekend..

I' don't know what causes this and don't have a solution.
I think something to do with the network / backburner?

[Itoosoft]

I think the last 4 animation projects we had the same problems. From 8 minutes to 40 even 6 hours and then 12 minutes. I can't explain..

Are you using Forest Pro as well ?

[Roest]

Nope,
The last project we used vrayscatter, but before it was a known problem.

[Itoosoft]

Nope,
The last project we used vrayscatter, but before it was a known problem.

Ok. I have a theory that problem would be in the vray proxies, because the render engine needs to load them dinamically from disk (or network) while rendering. This would be have a impact in random render times, because the network load or other factors.

We have a post in our forum about this issue (for Forest Pro). I suggest to use meshes instead proxies, to check if there is some difference, since the meshes are already loaded in memory when render starts:

http://www.itoosoft.com/forum/index.php?topic=351.0

Of course this is only a theory, and i can be completely wrong... but i believe that with these type of problems any new idea would be helpful.

[Roest]

Sounds plausible.
Yet the solution to use meshes instead of proxies isn't doable for many cases.

[Itoosoft]

Sounds plausible.
Yet the solution to use meshes instead of proxies isn't doable for many cases.

Well, i mean to use meshes instead proxies in Forest, because both types are converted at render time in VRay native instances. This can be done without any performance penalty.

[Morbid Angel]

I recall actually having a similar problem on the farm. We had our frames rendering on local machines anywhere between 15-30 min a frame. On the farm it was anywhere between 15 min to 4 hours.
Solution was to copy all the assets to local drives of all machines. The render time went back to "expected". We never used that farm before so we did not know what kind of network they had.
You might want to look into this as a test.

[Roest]

Well, i mean to use meshes instead proxies in Forest, because both types are converted at render time in VRay native instances. This can be done without any performance penalty.

OKay, misunderstood.

@Morbid Angel:
I think i will try this. It also explains why we cant start a animation in backburner with 8 comps at the same time.

[Roest]

Well, after a few test locally (every resource on every computer), i can say:
It renders ROCK SOLID!! a dropdown in rendertime!