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A recent little ditty I was putting together gave me a devil of a time with render speeds... kept taking forever.
This morning, I discovered why: Subdivision. Something had somehow cranked up SubD on each of the two Genesis 8.1 figures from the typical 2 - 2 (SubD level and Render-SubD-Level, respectively) up to some obscene amount like 3 - 5. This had the effect of blowing up the scene Geometry weight from maybe 200 MB to an obscene 2.4 GB, which in turn turned a typical 10-minute render into a 2-hour one.
So if you find that your render times are getting ugly, maybe you can fiddle with the SubD sliders a bit, maybe turn them back down to something tolerable.
Took forever to find out why the render times went nuts, and I can only guess that maybe someone built a couples Pose Preset with a few additional (and IMHO dumb) setting-changes in it? I'll have to carefully test and find out (can't recall offhand which, since I test out a lot of different-but-subtly-so pose presets as a base for what I eventually want and tweak from).
It's the only theory that comes even close to why the SubD all the sudden got jacked w/o any intentional actions on my part. I got there because sometimes a pose preset will add morph settings nobody asked for, so it's not beyond the realm of possibilities that someone ganked in SubD as well. The characters themselves I've had for awhile, and never had issues with them before, so...
Yes...That was the problem...Long render times. This SubD is the SOB.
Have just tried this out...and booom Sunshine everywhere.
Thanks for the hint. Also good when you use the Iray preview..Much smoother.I am sure I am not the only one that has a Rush song playing in their head when reading the title of the thread.
🙂
In the high school halls, in the shopping malls...
Nope, now that you mention it, it's not just you 🙂
Not really. A SubD level of 2 is quite smooth enough. Also, if you crank up the SubD levels too high, you stand a great chance of seeing weird deformations in arms and legs.
Most figures can do just fine with a SubD level of 1 - especially for full-body shots. If you're doing up-close work (like 'inspecting skin with a magnifying glass' close), then maybe it would help a bit, but otherwise, SubD is something you don't really need that much of.
Best way to go about it is to crank it down to absolute minimum (1), render, and see what comes of it. If something looks chunky, you can turn it up a little, render again, and see if that fixes things.
It certainly makes a difference GOF. I dropped my 4 characters from SubD 2 to 1 and it rendered in about half the time. No obvious deterioration at a distance of a few metres. When I want to render closer I'll need to up the SubD level back to 2. Thanks for your suggestion.
Some HD characters default in subD4 so at subD4 they don't need to use normal maps. Without normal map a subD4 character can render probably as fast as subD2 using normal albeit it will need more VRAM. It's more flexible and easier to use subD to adjust between distance and close shots than sticking with lower subD and normal maps. Geometry over texture tricks is the future with GPU getting more VRAM.
Good points @I53570k. I noticed that when I reopened the scene the characters had defaulted back to SubD2. Most of my scenes are complex with lots of things in them so reserving my 8GB VRAM is a priority. The "texture reducer" script is a godsend for some scenes.
Along with this don't underestimate the value of re-starting DS or your PC after a couple of renders. This stood out yesterday with a render that sat on 0% for 10 minutes, then crawled to 15% in 15 minutes. After a DS re-start the whole thing rendered in just under 9 mins.
I use Iray preview a lot during setup and I think this messes with VRAM when I go to render.G8.1 (default) loads with viewport subd at 2 and render subd at 3 (as opposed to G8's 1 and 2, respectively). Each step up in subd level quadruples the polygon count (approx 16,400 @ subd 0 => 1,050,000 at subd 3).
If you're loading a character preset, as supplied by a PA, they may have set their own subd levels - usually to match the subd level they sculpted their HD morphs at.
For visual difference, I generally don't go above render subd 2 unless it's a close up. This level gives a smooth outline, i.e. no polygonal angles, and captures the larger detail introduced by HD morphs (the rest can come from normal/bump maps). If you are going to rely on HD morphs, then a higher subd may be necessary. As a rule of thumb, geometry renders faster than normal maps but uses exponentially more vram the more subdivisions you go up by.
As for having to restart DS - whether that's Daz or Nvidia's fault for not releasing vram properly, I don't know, but I suspect it's more in Nvidia's court. I'll tend to tweak render settings using iray preview, then save the scene and restart when I'm going to do the full render, just to clear out the cache.
BTW thanks for the Rosemary Winters Tweaked Head Morph @Duval99. I haven't DL the model yet but she's very tempting.
No worries, @Frank22 - I think it deserved a little TLC as the overall character is very good.
Well I just DL her and she does look well made when I took her for a quick spin. Where do I find your correction tweak in the parameters list?
....sorry GOF for hijacking your thread
Good point on normal maps vs. SubD...
Also, I normally tweak-up my own custom chars, then save them off as scenes, so they always open with the SubD levels I originally set them at. My thing is that they had changed out from under me, and I never thought to check until I stumbled across the dials.
DS crashing of slowing to a crawl is an ultra-rare thing for me. I tend to not use iRay preview though, unless I'm dorking with something really low-poly or older figures that are light on system resources overall. I also tend to turn off DS when I'm done messing with it.
I do notice that DS won't shut down completely. I found that out when I turned it off ocne, then forgot something and turned it back on - and discovered it wouldn't restart. A quick peek in Task Manager of all things showed me that it was still running from before (and eating anywhere from 3-6GB of RAM). Subsequent testing showed that if I want it truly shut off, I have to kill the process in Task Manager after I shut it off. It will shut off on its own in 10 minutes or so, but otherwise it tends to linger behind-the-scenes... no idea why.
I haven't test this yet on 4.15.0.30, which I just updated to late last week.
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