On rendering time
akmerlow
Posts: 1,124
Been looking at some of threads and galleries (i'm just a random stranger from D|S land yet, but got very interested in Bryce lately...), so i wanted to ask what are "key" conditions for situations in which renders take "days" and in which take "hours"? I noticed in Slepalex' gallery (for example) that some renders were 40 hours and some were 7 hours , both were landscapes with lots of vegetation.. Curious (and a bit afraid what could happen if you dont have perfectly stable electricity in house).
Hansmar said:
I hope that Horo and Rashad will answer on the duration of rendering question, because they have much more expertise in this, than I do.
Slepalex said:
What can I say? The duration of the render is too big a topic, for which you need to create a separate thread on this forum. Maybe she's here, look!
If you often turn off the electricity (this I have also happened!), That is, the possibility of rendering in parts. You can stop the render, save the current state, then continue the render from the saved state.
Horo said:
render time. It's always too long, people want a result in a few minutes even though they worked on a scene for several days. It is not easy to give you a straight answer.
Many lights with soft shadows take time. Doubling the IBL quality about doubles the render time, if soft IBL shadows are used, yet very much longer, but without IBL shadows at all the render is fast. Transparent materials take a lot of time. If rendered regular, depending on the lights and materials used, anti-aliasing may be faster than the render itself, or up 12 times longer. But Anti Aliasing can be adjusted: Radius, Rays and Tolerance.
Super quality mode is extremely slow. Premium can be faster than Regular but also longer, or much longer. Each higher Rays per pixel (rpp) setting about doubles the render time. An average render works fine with 9 rpp, True Ambience usually needs at least 64 and often even 256 isn't good enough. But adding more options in the Premium Effects doesn't prolong the render very much. Maximum Ray Depth also increases render time. Default is 6, usually 3 to 4 is enough. However, if you use opposite mirrors, mirroring the mirror, you may go up to 100 or more.
Each doubling of the document size quadruples the render time.
My strategy is, once happy with the scene I check the render time on a small document size. If I think it's going a bit long, I start eliminating lights and reduce quality and see if the end result changes. Often enough, there's more in the scene than necessary and these things may make the render longer.
That's it in a nutshell.
Jamahoney said:
On the render-time issue, Akmerlow - I'm currently running (right now) an animation that will take 1 day & 20 hours. I'm breaking it up into several small time period units (~ 3 hours) where Bryce allows me to stop such an animation in its tracks, save such a portion, continue on to the next following portion - when I need, is appropriate to...etc. It doesn't seem long when broke up, so organisation is vital (oh, and a little patience, I suppose). That said, while the Bryce render is runnng in the background, I'm also constructing a book, playing around with images, looking at a movie...multi-tasking...
I will finally merge ALL together using a graphics software - in my case, it is Sony Vegas, Movie Studio Platinum 15.0 - in a few days/weeks or so: the final animation perfect and editble.
Horo said:
not for an animation as Jay explains, but for a still render there is also the possibility to plop render parts, save each part and assemble the final image in a graphics application. This is helpful if the mains power is not reliable and the render is going to take long. This idea actually came from c-ram a while ago and I wrote a PDF (https://horo.ch/docs/mine/pdf/Plop-Mask.pdf) which features a link to an easy to use plop mask.
Thank you for answers! I quoted them to this thread, so it would not get lost in "renders" thread. I wish this forum would allow "search by thread title", so... If there is an older thread on subject, please merge with this.
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Comments
If you search for my Gallery and have a look, the vast majority of the renders in there took about an hour to render... Two hours at the most unless specifically stated otherwise. I run a 12 year old Mac Lap Top (the black Regular MacBook not the Pro).
The short answer from me is: Always use Premium Render where possible. NEVER use Super for ANY reason what-so-ever as it's a real slug with no advantages I can find.
Glass trees, anything with transparency is going to take longer (minimise the Mac Ray Depth to what is acceptable for your scene (usually 3 is fine, default is 6 and you can save quite some time reducing it to 3).
Volumetric materials (Clouds, smoke, fluff materials) are going to take longer to render. Minimise this by using the Volumetric controls in the Material Lab. The Quality/Speed setting is usually a compromise worth taking... Towards the Tortoise will make the render longer but will put more layers into your volumetric material making it look better. Towards the Hare will speed up rendering but use less layers to make the material and sometime payering is visible. Plop rendering it the best way to see exactly at what point the layers show so you can set the Speed/Quality appropriately.
IBL Lighting is complex but gives great results. Again reducing Quality is mostly not noticable (especially where Shadow Blur is switch on and turned up a lot). Excluding volumetrics from IBL is a great way to speed up render times, but you will mist likely have to tweak your materials a bit as they won't be getting the same light as the rest of the scene.
True Ambience is excellent but means you have to increase the RPP setting (though 32 or 64 is usually good enough, no need for every render to be 144 or 256).
Well that's the short answer... Damn, I'm gald I didn't type out the long answer, that would take all night.
Important: And I forgot to mention it.
If you have a multi Core processor, take full advantage of it by setting the priority to 'High'. Horo can better explain the technicality of this. I can say it speeds up your render time a lot. When set to 'Normal' Bryce will only use one core to render, when set to 'High' it accesses all of them I think.
See attached screen grab to find this setting.
Would it also help if my cpu only has 4 cores, not 8? (also haven't installed that LAA thing yet)
I'm a Mac person so don't know much about LAA, I've heard of it of course but have had no reason to learn about it. :)
As far as I'm aware 4 or 8 cores makes no difference, Bryce will use as many as it can. Others it will leave alone. My Mac only has 2 cores so again that's never been an issue for me.
Bryce does everything on the procressor, people sometimes think that a fancy graphics card will speed it up, but it doesn't.
akmerlow - it will. Here's what the Priority settings do: Low takes 1 core, Normal takes half the available cores (of max 8), High takes all the cores. All means 8 at maximum. During dev time we went to 16 but agreed to keep it at 8 because the more cores used to render, the more memory is needed - and with only 32 bit the memory gets soon exhausted. So with 8 cores it is 1-4-8.
Mind that hyper-threading doesn't mean that a 4 core CPU has suddenly 8 just because the Task Manager shows 8. The hyper-threaded or virtual cores add about 15% of speed in average while power consumption - and heat - increase more than 15%. Those 15% are average, in my measurements it can be as low as 10% or as high than 20%.
I have a 4 core i3 (my back-up machine) which I use at High priority for longer renders. The main machine is an i7 with 4 hyper-threaded cores (pseudo 8). Here, I always use normal so I can still use it while rendering away. Bryce takes the real cores and what remains from the virtual cores is ample to use the machine for other tasks.
I wanted to try a very lowres texture tiled to try if it gets rendertime down,but seems bryce don't take .jpg etc as import to bryce materials,so it seems I need to set it outside of bryce with hexagon or other 3dapp and import to bryce,if Horo doesnt have a solution to that?
Mach25: Yes, Bryce can import .jpg files into the material lab, but it may not be obvious exactly how so I'll give a very quick explanation.
Select the component and click the 'M' (material Lab) button in it's little side menu.
In the mat lab, drop a ball into the 'Diffuse' hole in Channel A.
On the right you'll see a box with the three micro mat previews with a selection of buttons.
Click the 'P' (Photo) button on the bottom row of the Channel A preview box.
Then click the second from the left on the TOP row (Texture Source Editor)
Click in the first available unfilled plain grey boxes in the bottom half of the window that opens up.
That will then open up a finder wondow where you can point your computer toward where you have saed your .jpg file and it will load into Bryce.
Then further edit the specular, reflection etc. in the same way you would with any Bryce material.
NOTE: though Bryce imports .jpg files, it uncompresses them, so you will not save anything by adding .jpg compression to the pics you import.
Hope this helps.
@Dave Savage :thanks very much
it probably uncompress any picture to internally work with hiprecision floating point channels
mach25 - oh yes, I do have a solution - the same as Dave Savage already gave. Pictures loaded can also be tiled and I have a video (link) how to do it on my website: Bryce & 3D CGI Documents > Videos > Horo > More Videos 4. Tiling Pictures on a single object.
Note that JPG pictures are compressed with losses in quality. Bryce decompresses it but the missing quality can not be restored. Bryce also removes Gamma for the rendering because it has a linear workflow and only adds Gamma for the saved the render.
The advantage of LAA is to allow Byrce to use additional memory that Bryce otherwise can't make use of, so you can cram more stuff into your scene or don't trip over memory issues while using it. It shouldn't affect the speed of the render at all (unless there's some obscure side effect I haven't thought of, but that's certainly not the purpose of it.)
Have to think about it once again.
I had 640x800 render being done in about 2 hours. When i change size to 864x1080, it promises me to took about 8 hours. 512000:933120 (overall pixels in both cases) ratio is 0,548 while 2:8 (hours needed) ratio is 0,25. I don't understand what are rules for time increase. Or those time predictions are more inaccurate at beginning than might have been.
edit:
I forgot to change "priority" to high (thanks for reminder, Dave). Interesting, it promises about 4.5 - 5 hours instead of 8 (as said before, my cpu only has 4 cores and i have browser running).
akmerlow - render time predictions for Regular rendering excludes the AA-pass, which can be swift or take 5 times longer. Prediction for Premium is lower by 10 to 25% than it will actually be. To render a work double the size will quadruple the render time.
_And good subject _
Quad-Xeon HT