Rendering interiors and render engines 2015

Hi, I’ve been with blender for some time now and have been with Cycles from the beginning, (see some of my earlier work on Blenderswap http://www.blendswap.com/user/Jay-Artist/blends).

I love Cycles - If you can love a render engine. But there are some occasions when Cycles just isn’t the correct render engine, one of the typical instances is interior architectural scenes. This is where Photon Mapping or similar is really important, Path Tracing in Cycles just doesn’t cut it even with excess samples – you could render a million samples but you just won’t get those rays into that corner to get that element of realism and a noise free render.

I was wondering what peoples thoughts are on other render engines for 2015, both free and paid. Some such as Luxrender, Yafaray, Mitsuba seem to be fading away judging by the amount of user art I’ve seen with them. Maybe users are more interested in Cycles as it’s more up-to-date and is continually developed, or are the old engines just not up to it anymore?

Is it even worth learning them if there isn’t really any new tutorials or galleries?

Luxrender always seems so slow too, even after rendering overnight on a quad core, and Yafaray has always been hard to get the settings right – a lot of experimenting = time wasted sadly.

Commercial renderers such as Thea, Octane and Indigo etc seem to be more popular than the old guys, but the users views can be mixed.

Also is Un-biased rendering really quick enough for a job? Can you render something within a few hours or is it like waiting for wet paint to dry when it’s raining?

Vray, the holly grail for some and is the king for commercial work usually, sounds great, but it’s very pricey for some and requires a custom version of Blender as far (as I’m aware).

Then there’s the up and coming free (free for non commercial) Pixar/Renderman engine this year (2015), but is this going to be any good for interiors or will you have to cheat the same way as you have to with Cycles to render them? (Removing walls behind the camera and all that jiggery pokery etc). Is there even going to be a usable plugin for blender?

Will Cycles eventually do something like Photon Mapping? Or is it just not that kind of engine? I’ve heard of MLT could be on the cards.

Plus there’s always the issue of some of us just not having the funds to pay for a commercial engine too, not all of us have good jobs, or jobs at all… sniff. So looking into commercial engines it’s important we don’t waste our time and especially are limited money.

Some users do have some loose change to spare (apparently) but oddly don’t use their paid for engines anymore – why?

I’m on Linux, so for some this can be limiting too what choices are available.

It’s a necessary topic for us all, what’s you thoughts guys, lets share!

Well, since Cycles is a path tracer, there are some rumors going around that it could do some of that path tracing thing :slight_smile:

oops, re-editted :wink:

Many archivis people use path tracers for interiors (octane is afaik also path-tracer). With the GPU it’s not actually that slow and you don’t need to tweak many setting like for example with photon mapping. It produces some noise, but the plus side is that there are no other strange artefacts.
I personally use cycles for interiors and I am OK with that. I don’t even need million samples for my finals - I usually use just 1200…

Try Corona render engine - its fast! but, as for now, I have problem rendering groups/instances - solution: triangulate modifier everything, make real everything (which is really troublesome).

maraCZ, I always find that Path Tracing for Interiors looks a little fake, you get a certain photographic ambiance with Photon mapping. Even after heavy post production there’s still something missing - many old Yafaray renders look better than modern Cycles. Most of the good Interiors in the gallery here are not Cycles too, others typically preferring Octane or similar. It’s always a matter of opinion I know in the end though.

mziskandar, It’s a shame that Corona isn’t available for Linux yet - from what I’ve read it’s just for Windows Vista and up. There are some great looking renders on the site though.

I thought I’d just share this from last year, I didn’t notice it previously - by Class Kuhnen
https://plus.google.com/101076135528517730950/posts/EzTptERtRhg

Maybe Irradiance Cache is what Cycles needs for Interiors?

Also posted was a neat little trick, by marcoG Ita:
http://www.blenderartists.org/forum/showthread.php?216866-Cycles-tests-the-new-blender-CPU-GPU-renderer-of-awesomeness&p=2571995&viewfull=1#post2571995

Makes such a difference!

If you want interiors (or any hard to light scene) your options are pretty limited if you want sane render times. BiDirectional Path Tracing with MLT is your best realistic bet, but aside from Lux (which isn’t king as far as speed goes anyway) you’re not going to find much in terms of free options.

Thea and VRay are truly the champs here. VRay has its proven stable of biased options, and Thea has an amazing proprietary method called Field Mapping which can handle even the toughest lighting situations in a reasonable amount of time.

I’ll wipe my previous statement as it was not much of an advice.

Yes cycles looks artificial I agree. Will post some cycles vs maxwell renders so OP knows that I agree with him.

For stills it is much easier for a trained eye to distinguish between flaws in light distribution and materials.

Cycles is animation centric meaning that the eye is less likely to find faults.

It is also very hard to make non-spectral renderings look like spectral renderings.

Have a look here maybe this helps ! http://opensurfaces.cs.cornell.edu/

I’ve been comparing render engines a lot lately and that “something” just isn’t present in Cycles renders. As I said previously I like Cycles and have used it since it’s beginning. I’m not here to slag off Cycles, it works very well, but it’s best for certain types of renders, not interiors.

That “something” is how the light travels around the room and bounces, and no professional artist would disagree.

I’m no fanboy and would like to know more about other users opinions that actually know what they are talking about, and hopefully have images that speak for themselves.

Path Tracing that Cycles uses does not give a good photographic/photorealistic style render for interiors like some of the commercial renderers do. No post work in the world will make them good enough in Cycles.

reC , Just look at the galleries here for interior Archviz and then have a look at the Thea, Octane, Luxrender, Yafaray, Indigo, Vray etc. you just can’t compare - if you don’t understand this, then maybe you should spend a little more time rendering and not advising.

“With cycles on GPU say GTX980 reference it is fast enough even for interiors.” - I have an Nvidia card and use GPU, but it’s not about how long something renders = quality.

It’s all very well doing post work on an a render, you have to for all renders whatever the engine, but you need the best start you can.

I was hoping that I’d get some users that who use/d other engines and get an idea of what they thought, not just in price, but pros and cons and how the old engines compare these days, even if they are still viable etc.

I’m not looking for advice on what I should buy or that I’m not using Cycles correctly. But what seems to work best for others for Interiors. Geez you’d think I was writing in foreign tongues or something!

Here’s 3 renders done by another artist (jan walter) the samples are Cycles, Luxrender and Indigo. The Cycles one could be improved with a little diffusion, curves and maybe better materials obviously - but this is what I’m talking about - the cycles one is pretty lifeless, missing that initial “something”. See which you prefer.

Even my Misses who knows nothing about rendering didn’t like the Cycles one and thought it looked artificial.

For better quality png versions check out the site:
https://www.janwalter.org/jekyll/rendering/cycles/2014/09/12/salle-de-bain-cycles-lxs-igs.html

Cycles


Luxrender


Indigo


There are two main problems with the cycles render on the example: There are no caustics and the materials do not use fresnel for reflection. If I remember correctly, lux uses glossy material with fresnel by default, in cycles you need to mix your difuse and glossy with fresnel input. The wood on the cycles render is washed out becose it uses too high glossy value on the faces facing camera. Other than that the diference is IMHO very small.

There is one very important thing:
Fresnel in cycles is somewhat inaccurate and different from lux or indigo fresnel.

It’s also important to keep roughness at low level (< 0.3)

I’ve never had much luck with Cycles Fresnel, never seems to work with real world figures, but forget that and the objects in the scene. Even on the basics the wall around the window looks so artificial in the Cycles one.

There’s also a natural bloom/diffusion/glare on the Luxrender and Indigo renders which is simulating the bright light reflecting on the lens and overexposing the scenes a little. They’re more photographic, and lets face it, that’s what we’re trying to copy, not real life, but what the lens sees.

Indigo applies vignetting to the image by default hence the “bloom” look.

Cycles uses the same exact material definitions as every other path tracer out there. They’re all based on the same exact white papers. The only difference between Cycles and the others is the lack of spectral light transport and caustics, and a simplified Fresnel term. As stated above, these things are for speeding up animations, which is the stated goal/purpose of Cycles, not archviz. Comparisons between renders are fairly useless, as material setups differ between material systems. Matching two beyond using the same models and textures is an exercise in futility. Additionally, renderers like Indigo do tonemapping as part of the render process, rather than using the direct floating point output of Cycles with sRGB color profile.

A lot of users seem to think you can achieve good archviz with Cycles - “Cycles does everything and your engine sucks!”, is what you generally hear. So it’s hard to read between the lines of what it is actually capable of.

As a path tracer I’ve always thought that it’s not possible, at least with Cycles currently. But there’s always a trick (see the above AO tip), or some other guy working on something to make it better - who knows the future.

I was unaware that Cycles was just intended for animation - maybe a lot of other users should know that to save them wasting their time.

m9105826, are you saying that if a user wishes to do quality interior archviz, that they should use something else?

And regarding other renderers, does anyone know if Yafaray and Luxrender are still contenders in 2015?

I was also enquiring as I’ve said several times already I was hoping for some personal opinions on other render engines that work with Blender, especially with archviz and interiors. The likes of Octane, Indigo and Thea, how do they compare? What’s the pros and cons for them?

Can you get quality archviz interiors with Cycles? Absolutely. Is it the best choice? Absolutely not. If realism is your number one goal, you’ll need spectral light transport and bidirectional path tracing. That means Maxwell, Indigo, or something similar. Your choices are quite limited in that respect, as bidirectional path tracing is very difficult to achieve with a full material system and production features.

Cycles isn’t intended JUST for animation, but its goal from the outset has been character-based production animation, similar to Arnold. Interiors that aren’t well-lit simply aren’t in the wheelhouse of any unidirectional path tracer, though. It’s just the nature of the algorithm.

Are Yafaray and Lux viable in 2015?

Yafaray, I would say no. It’s simply incomplete in terms of feature set and development is somewhere slightly above non-existent.

Lux in its current form is slow. However, the core of Lux is in for a huge update fairly soon that will modernize a lot of the cruft that’s been sitting around since it was a new branch of PBRT. What this means for users remains to be seen.

Octane suffers from the usual GPU woes: vRAM limitations and feature set limits. That said, it is the most advanced of the GPU renderers and will suit most artists working with archviz well. Just don’t plan on including much in the way of exterior renders with grass and trees, as you’ll quickly run out of memory even with instancing.

Indigo is a good choice. It’s a solid bidirectional path tracer with decent speed. I personally hate its material system, however.

Thea is my personal favorite for interiors and hard-to-light shots these days. The material system is idiot-proof, and between its biased and unbiased integrators you can light any scene you throw at it efficiently, with a little knowledge of when to use what, of course. It even has a GPU previewer now that is almost completely feature full. Its Field Mapping in the biased renderer is very impressive and efficiently lights interiors in cases where good old final gather and photon mapping fail.

Of course, the gold standard is still VRay for archviz. But it’s expensive, and I’d argue that it’s not as far ahead of the pack as it once was in terms of speed and cutting edge render options.

Thanks m9105826 for the intelligent response!

Thea does look good, although at £223 (€295 euro) it’s a bit of an expense unless your working. Indigo RT seemed a better alternative, as it’s £109 (€145 euro), Although Octane is an incredible £315 (€416 euro), you even have to pay for the exporter!

There’s some good rendering to be had out of Yafaray, but getting anything out of it is very hard I found in the past. Luxrender for me is good, but really slow - maybe the major update that is coming will improve things, here’s hoping as my current income is probably only going to stretch to free or at a push Indigo.

Maxwell and Vray though, yeah, ok :wink:

Hi, just dropping a better setup for the AO shader trick linked above.

Diffuse BSDF becomes AO BSDF after a user defined number of bounces just for Diffuse Rays, without the need to take care for refraction and glossy materials.

Example
https://db.tt/WFi2GXiN

BTW if we had light portals interiors would be quite faster. (when using HDR or Sky texture)

Cycles interiors can look artificial in cases because…

    • Materials do not have fresnal, don’t let the incorrect fresnal node stop you because you can use use custom curves with the Layer Weight node ‘facing’ option.
    • Many people do not use the more advanced curve mapping function available in the color management panels, with the right curve, you can get a significant reduction in the amount of burnout in the image.
    • People don’t make any use of GGX specular shading, I usually just use a group node that can mix the Beckmann and GGX models for allow for a custom falloff depending on the material.
    • Cycles is not spectral, this isn’t so much of a big hurdle against Cycles if you apply the last three points to the image, but it eliminates the possibility of a simplistic method for adding Cauchy B dispersion or other spectral effects in the image (you will have to create a node setup to approximate it).

Even in the case of caustics, you can use a combination of lightpath tricks and the ‘filter glossy’ option to get some of those effects in, there’s no shortcut though for really good caustics outside of thousands of samples though.