Artby - Final

Started by Artby, January 27, 2015, 03:09:17 PM

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The river looks like it's running downhill and could do with some rapids?


Hi all !
A lot of work since the last time. I decided to bring back the mood of my thirst image, but with more terrain and river work (from what I have learn with the second image). But I have now a big rendering issue. A part of the mountain is taking so much time to render, I don't know if it will finish a day. When I am working in 700px width, detail 0.3, AA3, it is taking about 5-8 minutes to render everything. But when I increase settings, here is what I get :


I have tried defer atmo/clouds, same thing append. Could you please help me ? I have no idea what to do, and the deadline is very soon...


Sometimes renders can take several hours!  what render settings are you using? What quality settings are you using for the clouds and atmosphere? With the water you probably don't need transparency, turning it to zero will greatly speed up rendering.


Yes but I my case, the probleme is localised in the black zone of the mountain. And I am talking about days, not hours (you can see the render time on my screenshot...). No problem with the water.
I am using a Xeon with 19Go RAM (at my work) and it is waaaay to long for such a config. Anyone has an idea ?

EDIT : What should I use in the advanced tab of the render node with such a config ? By default I have min thread : 1; max : 64; size subdiv thread : 1600; buckets are 256x256

Atmo is 32 samples (I need them for this scene), 4 localized cloud layers, about 0.5 quality for each one, no acceleration


Here is my project file...[attachurl=1]

(EDIT : On the share file I've check receive shadow from surface but the problem is not there, I had it before)


The haze density setting of 28 may be the cause - try reducing it and adding a smooth cloud layer masked by a density shader with a very low cloud density instead.


Wow, 28! Hehe. Yes, this may be better handled with a cloud layer instead of the atmosphere. Still I'm not even sure why that would be causing such longer render times *in a particular area*. At 32 samples I could see it taking a while in general, but why that particular part of the mountain? What's there that's not everywhere else?

I will say that outputting all render elements like in your scene file will slow things down a bit and use more memory. I doubt you need all of them, so you might consider narrowing it down to the elements you're actually using.

Other than those two things there is nothing *immediately* obvious in your scene file that would be causing such a problem. But if you're aware of using a Reflective Shader anywhere but on the water (i.e. on the mountain somewhere, somehow), then reflectivity could be a contributing factor (I didn't see any such shader in that area though).

- Oshyan


Thanks for the fast response, (this forum is amazing I have learn so much here and it is continues)! I am trying this. I used Vue in the past, and in this software rendering low density clouds was way longer than increasing haze density. Now I am in TG (and very happy with it !!) I have to change some of my habit...


In the last node (snow_1-1) you use a color derived displacement of 3m with a smallest sized fractal of 0.01, which might very well be the culprit. If  you use color to drive displacement, it's better to decrease color roughness. But still, 1cm on the far mountains snow is way too detailed.
Furthermore; why do you use a twist and shear shader in a color setup (without even a stretched fractal base)? Any particular reason and effect you were after? I don't think it's doing anything.


Wow thanks Dune I think you are right about the snow displacement, and it makes more sense about the localized render time (and the fact that in lower render detail it do not have any issue, TG may skip this small details)! I have already used huge haze density by the past and TG generally handle it nicely. BTW, I am doing theses changes right now and hope my image will be rendered :)
I wanted to distort a bit the brown sand, but has you said twist and shear is not doing the job when used like this... Of course I need to work more on a lot of small things, but I needed to fix the render time first, so I can progress.
Thanks again everyone!


Finally I get something :)
With detail 0.6 and AA4, it took 10h40 in 1600px width. AA5 is looking a bit better, but I may use it only for final render.

Dune, I test what you think was the problem, and still have a very long render time with AA5 on the center of the image, for no reason... I am now testing the low density cloud instead of the haze, but it is quite hard to get the same result...
I am also working on the river flow and the ground detail with a "test atmosphere" to work faster... The next nights are going to be short :p


great improvement in render time, and this is looking great so far!
now for the final push...
get the coffee on!


The dark cloud out of the cone is excellent. In all, I think you have achieved your goal.


I had another quick look; your fractal warp is quite strong and together with small displacements that may increase render time. Also the compute normal before the snow takes a lot of time. Do you really need the latter?


Thanks a lot Dune, problem solved! The compute normal was taking about 40% of the render time in standard settings, and it may be more in high settings :)
It will save me until the deadline as I can work faster...