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ivobakker
05-19-2010, 02:21 PM
I work with Maya and Mental ray quit a long time. The results I get are already really good.
But i think i can still be better, but I do not know how. When i sometimes see other renders they just look a more photorealistic. Especially the vray renders look more realistic. But i think it should be possible to stay with Mental Ray.

I attached soms images of one of my latest projects. Does anybody have some tips to get them better ? I mean technically. The way the furniture is positioned etc is how my clients like it.

I only used final gather, a sIBL, a physical sun and area lights in front of the windows. All the materials are mia-x. I used light profiles on the lights. And of course some Photoshop work.

Some options might be:
- use gi
- importons
- other light setup

I hope you can give me some tips to make the images better without having to switch to another renderengine.
Tnx!

ctrl.studio
05-19-2010, 02:41 PM
linear workflow !?

ivobakker
05-19-2010, 02:47 PM
I have to find out a bit more about the linear workflow.
What i do now is put the gamma in my exposure node on 1 and the gamma in the render setting on .0455

A lang time ago i used the gamma correct on al the texture and used a gamma of 2.2

Would it make a diffrence to use another method ?

vyeshaun
05-19-2010, 03:29 PM
linear workflow !?


These tutorials cover getting images in the right colour space


http://forums.cgsociety.org/showthread.php?t=657518


I wouldnt know what I would do without them now. Absoloutley amazing and should be more on what you are after.


P.S using this method you dont need to attach a gamma correction node to every file texture. And if you do when you arent in true colour space often you just end up washing out your textures colour.

cgbeige
05-19-2010, 03:33 PM
I think that part of your problem is the fish-eye lens. It makes everything feel smaller and you're getting a dollhouse effect. I think this is made worse by your scene and light scale - there is too much light bouncing onto the ceiling so it feels like your room is 3 feet tall. If you can scale everything up 3 times and shoot with a narrower focal length, it will feel real. Try and shoot from further back with a shorter focal length instead of close in with a fish-eye. It makes the space more engaging - as it is, your central objects feel like a tiny part of the ROOOOOOOOOOOOOOM. It's really only bad in the kitchen shot though.

irwit
05-19-2010, 05:33 PM
Linear workflow will help but it wont give you a "better" image.

Your lighting is very good as is your texturing and shaders. However I can see a lot where you can improve on.

A big thing I notice in your work is lots and lots of perfectly straight lines which jump straight out to me as cg. You never get that in real life no matter where you are. Your worktops would have slight irregularity, your chairs wouldn't be perfectly facing the same way as the table, the wooden flooring could never be laid that perfectly. The roof lights all face perfectly the same way. These are all things that's subtlety tell you the image you are looking at is fake.

Another thing I would watch out for is scale. Your rug on the floor and the chair legs look too big in comparison. I cant say for sure they are but straight away they do look odd. I would check out things like that too.

I think basically are better than reallife which is a great achievement and probably what most clients would want, but if you want to achieve greater photorealism then you should try and make your images less perfect and more like real life.

ivobakker
05-19-2010, 06:49 PM
Tnx for your reply.
I understand what you say about making them less perfect. But i do not think that is what i am looking for. I make real estate images wich are used for selling these houses. So i can not make the to imperfect. My clients will not like that.

I attached an image wich maybe shows what i mean. The render quality is just more realistic. I know it is a different kind of shot (more detail bigger focal length) but i just want to show the quality i mean.
The example is made with vray. I hope i can do the same thing with Mental Ray.

I think something can be done with a bigger focal length. But the problem is that i have to leave the house like it is. So what i could do is step outside the house and hide the wall.

smaragden
05-19-2010, 08:12 PM
Tnx for your reply.
I understand what you say about making them less perfect. But i do not think that is what i am looking for. I make real estate images wich are used for selling these houses. So i can not make the to imperfect. My clients will not like that.

I attached an image wich maybe shows what i mean. The render quality is just more realistic. I know it is a different kind of shot (more detail bigger focal length) but i just want to show the quality i mean.
The example is made with vray. I hope i can do the same thing with Mental Ray.

I think something can be done with a bigger focal length. But the problem is that i have to leave the house like it is. So what i could do is step outside the house and hide the wall.

The biggest difference in this picture and yours is the reflection map on all the wood. And you can also see that the reflection from the outside have a very cool color. And that's something that often sells an image like that. Good white balance between the cold sky and the warm sun. And some DOF, and some glow in the overexposed areas really help.

Keep up the good work.

/Smaragden

cgbeige
05-19-2010, 09:09 PM
to me, the biggest difference between your work and that image is the composition and colour grading for a more photographic/less straight out of V-Ray look. That and some depth of field. 30 second in Magic Bullet and it's got more of the feel I think you're looking for:

http://grab.by/grabs/a65993af5aa6e4e74b858850188d457e.png

I'm not saying it's perfect - just that a little bit of treatment helps a lot.

smaragden
05-19-2010, 11:23 PM
I'm with cgbeige, you should treat your render as a clean capture of your setup. The things that normaly happens in the camera and lightroom you should simulate afterwards. And it's often a combination of trial and error and experience.

drmaya
05-20-2010, 09:19 AM
if u need my advice
simply.switch to vray.....
it's much more realistic than mentalray
Anas

irwit
05-20-2010, 09:25 AM
I definitely agree with cg beige, as a compositional piece it is a much nicer image, colours are natural, lighting is flattering and is makes for a nice image. A lot of thought has gone into your example image into how how to make a nice image, as a pose to, "how can I show what this room looks like"

However another big thing with that image is the imperfections in it that make it so life like. The wood is not completely flat or even, the amount of reflectivity is not perfectly distributed.
The curtains are a good example too. You would never have folds like that if you were trying to sell those curtains. The curtains look very natural, like they have hung there for a while and developed their own fold through wind and use. They haven't been perfectly placed before taking the picture.

The chair and stool are not perfectly in line and neither is the lamp aligned with anything else in the image.

These are all small details that help sell the fact that this is real.

sander0105
05-20-2010, 11:57 AM
I would try a longer focal length. If you take the human eye in consideration a value between 35-80 should come closer to what we perceive.

The lack of imperfections makes the model look artificial. You could try to introduce some minor imperfections without making it look messy (messy wont sell). Especially the larger surfaces like the ceiling and the wall could benefit from this. Especially ceilings are almost never as smooth as they appear in your renders. Use a combination of bump and specular maps to achieve this.

Besides the introduction of DOF you should also consider the loss of saturation over distance. Colors further away appear less saturated. (although this difference is very low, it helps).

Some of the props you use lack a good set of textures to make them look natural. Especially the fabrics have this problem. The pillows are to smooth and the towels lack good wrinkels etc.

Hope this helps!

Zie je woensdag ;)

cgbeige
05-20-2010, 04:25 PM
also - there is a weird glow around the light fixtures, as if you dodged them in Photoshop. Is that photons or something? I think this is your main problem with the lighting - larger objects are being lit like they are small so the room shrinks.

PacManiac
05-21-2010, 06:02 PM
I see what you're saying about your renders.. you've done a real nice job, especially in the last one, but the lighting still doesn't scream photoreal. Ok, I'm going to try and list a few things that stands out to me and see if you agree..

All items on the sink - second image - look very cg due to their shading (those fruits especially, they need a softer look) and also suffer from almost an odd fisheye lens effect as mentioned. Those pots behind the sink... I wouldn't even think a real fisheye lens would squeeze those up that much but I'm probably wrong.

The lights in the ceiling variably lack shadow definition, the sofa - again second image more than others - has too much contrast to look real, so does some other objects. I would've expected a bit more shadow behind the drapery but not much.

The shadow under the table in the first image looks flat and your plants could do with some SSS or translucency.

That's what stands out the most to me, and I think you can get better result with a somewhat different lighting approach. I would try using GI (remember to use a portal light at the windows, throw out your area lights at the windows and use your sun with portals), the linear workflow you have going should be ok but there's issues with AA unless you do things a specific way. I can't remember what right now as there's a few ways to do it but unless you see problems with it you should be ok. I'm personally trying my hardest to stay away from rendering in MR for Maya at all for reasons too many to mention.

Try multiple light bounces as well unless you haven't already, that could make a big difference for that sofa I mentioned for instance.

MR in Maya can give you great results on par with Vray if you grip it by the throat and squeeze hard, so I'd try a few more things first. I hear Vray for Maya works well btw...

If you use 2011 with GI and FG be sure to download the hotfix as they screwed up bigtime in the 2011 release.

Hope this helps.

Dangeresque92
08-05-2010, 04:15 PM
To my eye, one thing missing is depth of field.

The fisheye look in the kitchen scene doesn't help, but the 100% depth of field only contributes to that "everything is to perfect" look, and its something you couldn't pull off with a camera in a real house.

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