Render Time Question

jlc767

Question for some of you that have been doing this for a while:

How long do you think it would take to render something like this?

http://laticis.deviantart.com/art/Raw-460266742

I ask because that's the caliber of 3D I'd like to one day be able to achieve. I look at that and... obviously it's great. But I'm messing around in entry-level / otherwise mediocre renders and I'm sitting on a 500 pixel wide (small) LuxRender for something like ~8+ hours and it's prolly only something like ~60% complete.

I have a pretty powerful gaming PC purchased a year or so ago (Win 7 64, i7, GTX670, 16GB). I realize it takes time and I'm OK with that, but... for these rare exceptions of simply gorgeous 3D (stuff like Metropolitan renders)... what's the render time on stuff like that? Are we talking weeks? Just curious.

Thanks!

SimonJM

First off, it was done in Octane 1.5 which means that it was exported from DS as an .obj format and imported into the stanalone version of Octane (the OcDS plug-in currently uses the Octane 1.2 engine).
It will depend on which 'kernel' the render used - much like DS has various 'render quality' settings, so does Octane from 'Direct Lighting' (which is very, very quick and still pretty good quality) up to Path Tracing (which is quick for what it is, and does very good lighting). Bear in mind all of these are 'in GPU' only un-biased renders, regardless of 'quality' level which is more down to (so far as I can tell) how well and accurately light is handled.
It will also depend upon how many samples the render ran for. You can increase the number in-flight to allow the render to run longer and produce more samples and thus produce a better quality render.
It is possible that the render took anything from 2 minutes (I am not kidding!) to 20 hours.
If I had to take a wild-ass stab in the dark, knowing nothing about the hardware involved, nor setting used, I would guess it took in the region of 2 to 3 hours.

jlc767

Wow. I'm creeping up on ~4 hours for this little 400 pixel laughing stock (via LuxRender standalone).

So, yeah... I guess I'm just making the renders take longer because I'm a noob and have bad settings / lighting? Are you saying it's about experience and efficiency for renders more so that brute PC power?

SimonJM

It's a little of both ... and it is also worth noting that LuxRender uses (mainly) CPU whilst Octane uses GPU for processing. And in that race GPUs tend to win! LuxRender can use GPUs (in either a hybrid - mix of CPU and GPU - or GPU only mode) but it is not as a mature a system as with Octane. You look to be using the hybrid mode - not sure why it is showing 0% GPU efficiency!
The setup of the scene: number of lights, the geometry (visible in render and not), materials (particularly glossiness) all help in producing efficient renders. As with most things, experience helps!
I've never been good at reading the LuxRender stats, but you seem to have run it out to over 7,000 samples per pixel (the 7.61kS/p value) which is really quite high: it will depend on the scene but a finger in the air figure of 2,000 has been quoted by Paolo (Pret-a-3D, creator of Reality) as being a good value to aim for. It looks like you have a few reflection bright points which, to me, would indicate bright lighting and/or glossy or specular materials. Is that window set to Glass and if so is it architectual or hyper-realistic (I forget the terms!). By the way, I have made an assumption that you are using Reality but you may be using Luxus as the intermediary to LuxRender. The end results will be pretty much the same (same render engine and all that) but LuxRender does a bit more hand-holding and hiding of the nuts and bolts of LuxRender. Luxus does a bit less holding of hands and exposes more of the 'underbelly' of LuxRender if you want to get 'down and dirty'.

jlc767

SimonJM said:

It's a little of both ... and it is also worth noting that LuxRender uses (mainly) CPU whilst Octane uses GPU for processing. And in that race GPUs tend to win! LuxRender can use GPUs (in either a hybrid - mix of CPU and GPU - or GPU only mode) but it is not as a mature a system as with Octane. You look to be using the hybrid mode - not sure why it is showing 0% GPU efficiency!
The setup of the scene: number of lights, the geometry (visible in render and not), materials (particularly glossiness) all help in producing efficient renders. As with most things, experience helps!
I've never been good at reading the LuxRender stats, but you seem to have run it out to over 7,000 samples per pixel (the 7.61kS/p value) which is really quite high: it will depend on the scene but a finger in the air figure of 2,000 has been quoted by Paolo (Pret-a-3D, creator of Reality) as being a good value to aim for. It looks like you have a few reflection bright points which, to me, would indicate bright lighting and/or glossy or specular materials. Is that window set to Glass and if so is it architectual or hyper-realistic (I forget the terms!). By the way, I have made an assumption that you are using Reality but you may be using Luxus as the intermediary to LuxRender. The end results will be pretty much the same (same render engine and all that) but LuxRender does a bit more hand-holding and hiding of the nuts and bolts of LuxRender. Luxus does a bit less holding of hands and exposes more of the 'underbelly' of LuxRender if you want to get 'down and dirty'.

Intersting about GPU. I'd sure love to be putting this GTX 670 to use! I'll look into it for LuxRender. And, as far as I know, my renders are pushed to the standalone version (I don't think my Reality plugin is functioning properly - there's some error when I check). I tried importing my scene as an .OBJ to Octane, but... first it crashed, then it did nothing (I have NO clue how to use that program).

As far as the scene I attached, I had a few lights within Daz3d, but... none of them carried over into LuxRender. So I deleted them, added a Sunlight, and just started the render with that one light source. I actually had the scene MUCH darker, with subtle blue ambient lighting, but, again, LuxRender didn't import my settings or chose to ONLY render the sun. I R CONFUSED.

Gunna try to get Reality 2.0 (plugin) up and running soon and see if maybe running the program (instead of LuxRender) helps.

Thanks for the help!

SimonJM

A couple of quick points:
Octane ONLY used CUDA-compliant gfx cards: which pretty much means ONLY nVidia cards.
LuxRender uses CPU and can also make use of OpenCL compliant gfx cards (NOT OpenGL, OpenCL), which ATI used to be better at.

DS Lights do not transfer to either render engine as, generally, only things with actual geometry get passed across. The exception to this is any DistantLight you rename to "Sun" (Reality 'cheats' and uses that to set up sun/sky in LuxRender) and any other lights that you rename to start with the letters "RealityLight". Reality will convert those across but they will not act like they do in DS as they will take on the physical properties of spotlights, etc.

As Octane is VRAM-bound (and until version 2.0 of the engine, also limited to numbers of various types of texture maps) you have limits to just how much 'stuff' (geometry and textures) will fit in the memory of your graphics card. I suspect you are blowing one limit or another. If using the latest standalone version of Octane ensure that you are running a recent (if not the latest) version of drivers for your gfx card (I had to upgrade the drivers to get 2.0 to work).

The 'usual' suspects for error messages in LuxRender are about invalid vertex winding order (which may be an issue as it can cause the appearance of the item to look wrong) and mentioning that a parameter type is deprecated (which is not, yet, an issue).

philiphowe

Just adding my 2 bits after using Reality for over a year now. It renders very quickly for me after following the advice of Paolo, who told me to just use one or two simple mesh lights (found under Reality add ons). I believe the smaller they are, the faster they render and the shadows are softer, or its the other way around. I usually set up one as my closer base light (warm) which casts shadows, then another with a cooler light for fill. That's it. I get more realism in a shorter period of time this way than monkeying with multiple lights and complex settings via Lux or purchased sets. I still love the Uber lights (Uber Spot Light shader) which have nice barn-doors, as in real photography lights that I'm used to. Same type of setup though for the Uber lights, one closer warm light and one cooler opposite or bounce.
Reality works very quickly with minimal tweaking, but I did enough online searching to find there are ways to get it even closer to photo-realism without much effort. I prefer the Image/Tone Mapping Kernel to be Linear, so I can easily adjust the settings, often starting with the Estimate Settings button and adjusting as I like. I don't use the SunLight very much unless its a large landscape scene because I have a lot more control with the 2 small mesh lights. They work similar to how the old pin-hole cameras worked, with great detail and render extremely fast. As a rule, the more lights you have in a scene, the longer it takes to render.
For my illustration work (www.philiphoweillustration.com) when I do 3d, if I use Daz, I usually combine the best qualities of the Uber renders (done in parts with alphas, the figure, middle ground, props separate, set, then background) then layer in the Reality render (which is nearly always the most realistic) and I get a beautiful mix by creatively layering in percentages. (dropping the opacity usually to around 50% of the base Uber and base Reality render.) This actually goes very quickly, I know it sounds complex but its quite simple really, and I have complete control in Photoshop to get heightened effects, contrast, color, etc.
Anyway, try just the one or two small mesh lights with Reality. When the guy told me how to do this I thought it was not going to work, but it makes a lot of sense now, far more sense than trying to dial in all these extra lights and push Lux or even Octane. I just got Octane and yeah, its the fastest by far, but its going to take a bit to learn how to tweak the materials for the best output. Its easy straight away, sure, but to get that polished edge will take a few days to play with. I'm looking forward to testing it all out as I think it might work well for animations... maybe. I'm getting the Daz plugin next, it only runs in version 1.2, but has the feature where you can paint in Photoshop on the skins and see it updated in near real-time, which is pretty cool since I am an illustrator/painter so I think I'll be able to paint in skin tone features, hair, etc, and see it update right on the model as it renders.
Oh, one negative on Reality, it will sometimes just sit there and not load in the file. I can usually get past this by resetting the Lux scene file name location and the Output location (or just change the name there.) Seems to have trouble at times finding those files, not sure why. I always render huge files, but they still go fast. Now, if its a skin issue, like when I converted all my V4 skins onto G2, and M4 onto G2 male (which saved me a ton of money and I can now build an army of Gen2 characters!) I noticed that some of them won't load properly into Reality. Also, that sample at the top of the thread that you posted is probably a quality skin. If you want quality skin renders for the realism, you should start with the best skin. I noticed a huge difference when I started buying the better skins, even the older V4/M4 ones they have on sale for 80% off. A lot of those are really quite good for the conversion to Gen 2 as a high quality skin to start with. Me like!
Hope some of this info helped.