All posts related to V2
By deep__dive
#368817
Hello!

First i want to apologize for my bad english! :oops:

I wood like to make renderings with more realism, and y know with the right materials it is possible to get it, but i have a lack of konw how...

Im never sure if the materials in my scene are right adjusted or if they increas the render time unnecessary or if they reduce the realism. can anybody help my, and have a look in my scene?

its a rendering from a meeting room:

Image

https://dl.dropboxusercontent.com/u/100 ... e%203D.c4d

Thanks a lot for your advise!

Peter
User avatar
By dariolanza
#368819
Hello deep__dive,

Well, "more realism" is a pretty vague question.

Your render is looking nice, maybe the yellow cushions are excessively saturated, but further than this, the image is pretty nice.
What areas do you think should be adjusted? What are you unhappy with?

And about optimizing materials: check that you were not using displacement where you don't need it (i.e. the carpet would work fine with Normal or Bump mapping, rather than expensive displacement), do not occlude the emitters behind a dielectric glass material, ...
Essentially what is described in this page from our online Documentation resource about optimization tips:

http://support.nextlimit.com/display/kn ... ation+tips

And take a look at these advises to speed up interior scenes like this:

http://support.nextlimit.com/display/tu ... or+renders

Regards

Dario Lanza
By deep__dive
#368833
Thank's for answer Dario!

The transparent curtains are a problem for mi. They not really realistic, and i think they increas much the rendertime. But ist really difficult to create a good Curtain material. Its the best i have found. (SheerCurtain). A render without them would be really, really clear. But so i think it would need one or two level more. The Rendertime of this render is: 25 Houres, SL 17.86. I think its enough for a Render like this (resolution 1700X1275), isn't it?

Other problem consist in the plaster material. In numerous Renders you can see really realistic plaster. But i can't creat a plaster material witch shows the strukture of the plaster in the Render. I don't know if the problem consist in the texture of the plaster or in the resolution of the Render. But also in a small picture it have to look like plaster. In the plaster wall you see very good that the render isn't clear.

Also the the fabric strukture of the chairs isn't visible.

Theres no material full diffuse or withe like 255,255,255. no displacment. it have invisible planes for direct light.
By dmeyer
#368837
I think you've got a good start, but for me, the uniformity in these pictures always gives it away.

All the chairs are exactly perfectly aligned and perfect replicas. Add some variation in placement and the chairs. Some might be damaged or have fraying. The wooden beam looks entirely too perfect. Dirty it up a bit!

Maybe there are some papers left from the last conference, etc.
User avatar
By eric nixon
#368843
I'm just looking at this scene now in c4d, thankfully its quite tidy. Ive just noticed the invisible ceiling emitter is intersecting the black downlight housing, also the materials are far from realistic.. but thats a long story. I'll check the rest of the scene.. hang on :)
By deep__dive
#368853
thank a lot for your help!

there is really a lack of variation. i will put some life in this picture! you're right, the other problem consist in the parameters of the materials. i had read a lot about the parametersystem of the materials in maxwell, but the problem for mi is more to know the parameters of each material in reality. where can i get them?
User avatar
By eric nixon
#368893
I'm rendering a version of your scene now, I turned off sky+sun and put big emitters outside the windows angled down slightly, it renders much quicker.

To be honest I was surprised that even skydome alone in this simple scene caused horrible noise, I turned off all invisible interior emitters, so the scene is fairly 'real' from a technical P.O.V.
Normally I wouldnt like to use 'window emitters' because the light falloff is too diffuse that way, but because of the curtain (which has gi + ref turned off) the diffusion looks about right. render is still quite slow sl18 now, but not noisy and has nice contrast.

sl18 70%reduced
Image Image

I had to change the textures, I didnt have the original maps, I didnt choose a very good mxm for the chairs though... I can upload just the c4d if you want.
By deep__dive
#368950
with this illumination it looks much better. but i'm confused. since i work with maxwell i have this problem that the sun und the sky cause much of noise in indoor renderings. i think thats the reasen that next limit has made the tutorial of invisible emitters. now you are saying that it isn't recomendable to use emitter planes in the windows because the light falloff is too diffuse. so i'm in doubt if maxwell is even usefull for indoor renderings? in the most architecture renderings i will direkt sunlight. an that causes a much of noise...

thanks a lot for your effort! im very happy to get some new imputs...
User avatar
By eric nixon
#368968
This is a complex subject, I do have issues with that tutorial, but it does help to introduce practical techniques which can help in certain situations.

The most problematic scenario is a bare window with overcast light, because the emitter outside window technique spreads the light too broadly (too diffused).

If your using sunlight its not so bad because, you can place a distant emitter to be your sun, and with some care that will render ok.

In problematic interior renders the best speed up, is to obscure / remove the back of the scene behind the camera, in order to let light rays escape or have right rays terminate (rear walls obscured by large hdr emitter set up to mimic the obscured view) - hope you understand, I'm not explaining it well, basically think of it as building a stage set, or carving your existing scene up into a stage set.

So to conclude, when it comes to interiors, some creative trickery is still required. In practical terms biased renders in expert hands provide 'good enough' interior stills (animations can be a problem), and ALL unbiased/brute-force engines slow down when the light rays take a long route to get to the camera, but the images are can be quite beautiful... after lots of practice I get great results with maxwell, so I would recommend you stick with it, at least because as a designer the feedback is much more honest.
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By Tora_2097
#368972
Yeah, interiors in Maxwell can be tough on the calculation side. I have rendered a whole lot of interiors in Maxwell and I tried to stay away from Sky/Sun as much as possible. Not only because of the noise but also I do not like the harshness in the rendering and many clients (and I too) prefer a more evenly lit space with "islands" of light caused but artificial light sources.
Even then I always arranged everything outside the cameras view to make it as easy as possible for the calculation. Oftentimes my backwalls have holes in them or solutions similar to what Eric has already described.
I have not used emitter planes in the windows so far, nor have I ever placed an invisble light source. I still find interior scenes one of Maxwells greatest strengths quality wise, but pretty unfeasible on even powerful single machine hardware. I need to render in 5k resolution and mostly aim for a SP level of 18-20. In the majority of my scenes that can easily reach into a week or more of rendertime on my machine so I use the Ranch for that.
In your particular scene -which Eric has already greatly improved-, I'd always start with the stuff that goes into Maxwell. Realism is as much about the modeling, texturing and plausibility of the scene as it is in the rendering itself. I consider it in fact the greater challenge today to obtain the proper input data as opposed to worrying about insufficient rendering algorithms.
What hit me instantly when looking at your scene is the straightness and perfect evenness of the scene. It's way too tidy and mathematical to look real. Every chair has the exact same wood grain for example, and I sorely miss highlight edges on everything. I also think that everything looks rather dull, as in lacking glossy reflections (though Eric put some in).
Usually for production scenes with little budget and time there is not time for that but as a personal exercise it might be worthwhile to explore this scene further.

Ben
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By eric nixon
#368975
Deep-dive, with regard to bevelling in C4D there is an amazing and free plugin, called ama-chamfermaker, find the latest version, adds bevels automatically onto 'decent' geometry. One more thing which isnt so important but, in that scene the instanced chair seat has a rendertime subdivision tag set to 6 subdivs, so loads of polys.. in each chair. naughty, naughty, but prob not actually slowing this scene down much.

Ben, its great to hear from you. I wish I had the knowledge/experience/methodology to get the results you've shown in the past. I think I've done about six or seven interior projects (not many) and artistically I dont really feel like they're any good or even really finished...., well I see the potential to make something much better at least. In the future its likely maxwell will have more sophisticated emitter options, in order to really direct the scene lighting, cant say much more than that.
By deep__dive
#368976
i see i have a lot to try! ;-) thanks a lot, it's very interesting!

this is a very new concept for mi, work without the sky/sun. im trying now to creat emitterplanes for the sun an the diffuse light. eric, can you upload the my scene with the emitterplanes outside, please? with my emmiterplanes i dosen't get enough light in the room, or when i increase the light, i get very much noise.
By deep__dive
#369013
so i have spend a lot of time reading in the forum. i know how to make a artificial sun. but what i didn't unterstand is the connection of a artificial sun and a hdri image.
Dario has correctly recommended the best technique, he omitted to mention that you need to choose an appropriate hdr and align it, prob because thats quite obvious and didnt need saying.
i have also used once the rear walls obscure technique in a bathroom with only one small window but when i let light enter in the back of my camera then the light situation changes either and dosent looks very real. but i think that why i dosent understand the second connection between the rear walls obscure technique and hdr emitter set up.
in order to let light rays escape or have right rays terminate (rear walls obscured by large hdr emitter set up to mimic the obscured view)
i didn't found a tutorial about that.
By deep__dive
#369017
so i did a few tests, all to sl 10

artificial sun and emitterplanes:
Image
curtains without sss gi and reflections
Image
curtains without sss and with gi and reflections
Image
curtains with sss and without gi and reflections
Image
curtains with sss gi and reflections
Image

it really looks like the curtains are the problem. without sss they don't look like curtains but sss makes a lot of noise. and there isn't a good tutorial for realistic curtains or a good material on maxwell ressources.

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