Stephen - kitchen scene

#1

First take. Thought I’d try for that contrasty light through window shutters look.
Attached a version with just the lights and one with gi/fg.
(Obviously, I haven’t setup a background image yet!)

#2

Another take. Thought it needed a bit of warming up.

#3

I think that you don’t need to warm up the room. Usually a room with shades in that position and sun light, is dark. I think that you need to take out the warmth of the room, make it darker but just let the stripes of sunlight to be your keylight. I think that maybe you should add later on , a very low cool fill light (Blue dark or similar.)

#4

You’re also getting some light on the top edges of the cabinet doors (below the sink). This geo is reacting to your Key Light, but in reality should be just as dark as the “front” of the cabinet door.

#5

Thanks for the suggestions. I think it’s actually a couple fill lights in the window area that are getting to the edges of the cabinets… forgot to turn on shadows for them. :banghead:
How about that dark, sharp shadow in the corner on the right side of the counter? I can’t decide for sure on that, but its sharpness is feeling a little awkward compared with the rest of the scene…even if corners usually are darker.

EDIT:
Last update before I go to sleep. Cooled things down a bit, fixed the problem with my fill lights (mostly…some light is still bleeding in on those edges), cooled down the room fills and increased their photon intensity a little, and switched some of the materials around. It may still be a little too bright. I can’t tell. On one of my monitors here, it’s far too bright. On the other one, it’s far too dark. :shrug:
I’m getting a bit of light bleeding over the top of the window…

By the way, does anyone else have a problem with batch rendering in Maya 8.5 looping its render cycle? My renders seem to be looping infinitely, on both of my systems. I have to stop batch renders manually, and by that time one of the render passes is bad because I’ve had to interrupt it midway in the render. :argh:

#6

Update.

First, after Jeremy went over the fg_occlusion shader last week, I decided to write my own. So, here’s a link to it, if anyone wants to try it out:
http://www.vfxportfolio.com/files/ca3d445/sg_fg_occlusion.zip
IF YOU DO USE THIS, NEVER EVER EVER SAVE YOUR SCENE AS .MB! It will break your scene! Save as an .ma (which is a good idea anyway!). Well… unless someone wants to buy me an autodesk sparks membership… :love:

To install it, put the sg_fg_occlusion.dll file in your mentalray/lib directory, and the sg_fg_occlusion.mi file in your mentalray/include directory. Both will be within your Maya install directory (which unfortunately means that custom shaders probably can’t be used at the school at all, since we don’t have read/write priviledges in those directories). After that, you can try just unloading/reloading the mayatomr plugin from within the plugin manager…but since Mayatomr is a buggy piece of crap, you may have to completely restart Maya to load it up. I have to do that when I’m debugging these things. :argh:
The shader will be found under ‘mental ray textures.’ Just hook it up to the surface shader slot of a ‘surface shader’ material. That can be used as a material override, to make things a little easier.

The shader, sg_fg_occlusion is a bit more robust than the built-in, single-option fg_occlusion shader, and offers a lot more of the parameters you see in the regular mib_amb_occlusion: max_distance, spread, etc. But I also threw in a couple options of my own:
(distance/spread)_falloff_center - The falloff from light to dark is interpolated across two curves. This is the center point, connecting these curves together. So, kind of like the middle slider in Photoshop’s ‘levels adjustment’ tool, and similar in function to the falloff speed of mib_amb_occlusion. But different.
(distance/spread)_interpolation - Sets the interpolation type for the curves described above. The difference between these is very subtle, but I think easeInOut is a little smoother than the others.

A quick note on reflectivity: Though it’s in there, it only half works. Try setting the max_spread value to be greater than 0 (reflectivity isn’t active otherwise, since it’s based on the spread angle), and you should see some changes…but it won’t be like with mib_amb_occlusion, where you have what looks like a glossy reflection. This shader doesn’t cast any rays of its own in a focused direction the way that the ambient occlusion shader does. Instead, it chooses to ignore samples based on whether or not they make up a reflected sample. But that’s usually only a small fraction of the samples cast in the scene, so when FG averages all of the values out in the scene, the reflected FG samples are sort of cancelled out. So, like I said, it only half works…
For similar reasons, you won’t be able to get very crisp edges in your occlusion. That’s a limitation of the technique, not the shader. So if you for whatever reason want an occlusion pass with really sharp edges, you’ll be better off with the standard mib_amb_occlusion.

Anyway, feel free to use it if you want. I used it for the occlusion pass I’m posting here.

Speaking of which, kitchen scene updates:
I darkened things down again (maybe a bit too much?), added more sky fills and increased their intensity, altered the angle of the sun light to make the shadow from the window more interesting, and brought down the room fills a small amount. Still no background image, but I’ll certainly have one in there by tomorrow. I hope to tweak more of the materials a bit by then, too.

No FG/GI

Occlusion

with FG/GI/Occlusion (not that this scene really needs the occlusion pass)

Any comments are welcome. It’s feeling…boring to me. Maybe the scene contrast will be more interesting once I get a background image in there. :shrug:

#7

I think it looks much better now, but how about some backdrop, instead of black that is shown through the window ?
To this kinda light setting, I would say try to find either an early morning pic, or sunset pic.

#8

Yeah, I have about a handful I’m trying to decide between. I’ll post an update after I’ve picked one out.

Also, I have another shader to post up for anyone else that’s interested. I thought this scene needed a slight touch of light fog. But after screwing around with Maya’s light fog shader for awhile, I decided that a shadow-map method just wouldn’t do it for something as finely detailed as light leaking through window shutters. So I went ahead and put together a light fog shader using ray tracing and ray marching.
It’s slooooooooow (well, that’s a given), but the results are worth it. It works with any type of light, and any type of shadow (be that ray traced or shadow mapped).
Installation follows the same steps as with my last post. Same warning applies as well: Don’t save as binary (.mb) if you use it. It’ll break your scene. Use ascii (.ma).

To use the shader, hook the sg_light_fog texture into the surface shader slot of a surface shader material. This needs to be applied to an object that will serve as the bounding geometry for the raytraced fog. This object can be of any shape, however it must be perfectly closed (no holes), should be set to not cast shadows, and your renders will be fastest when this object takes up the smallest volume possible, while still enclosing the light fog space you need. Then just turn on raytraced shadows for your light, and you’re done.
Visibility of materials through the fog isn’t working just yet, but I know why. However, it’s also quite difficult to get custom Mental Ray shaders to play well with Maya’s light linker (the shader uses every light in the scene), so this is the sort of thing you’d want to setup on an entirely separate layer anyway.

Link:
http://vfxportfolio.com/files/ca3d445/sg_light_fog.zip
Some test images:

A test with the kitchen scene.

A little off topic I guess. I just felt that the kitchen was begging for some volumetric lighting. :wink:

#9

Once you get the BG image in there it’ll be easier to comment on the lighting match. If there’s any hint of sky light in the background picture, you’ll need to match that in your lighting, before you add GI. (If there’s a sky out there, I’m not letting everyone get away with just giving me a sunbeam and no sky light for a 2nd week!)

Maya light fog can work OK with enough sampling, but MR’s parti_volume shader can work better and will work uniformly with all the lights in the scene. Render speeds get slower with a smaller step length, but usually aren’t that bad.

-jeremy

#10

Alright, trying out a couple of backgrounds:


If there’s any hint of sky light in the background picture, you’ll need to match that in your lighting, before you add GI. (If there’s a sky out there, I’m not letting everyone get away with just giving me a sunbeam and no sky light for a 2nd week!)

I did add a few fills for the sky and increase their intensity… do you think I still need more fill from the sky?

#11

Actually I’d be careful with adding in light fog. I think the “foggy-sun-ray-look” should be used with extreme discretion and care. It’s sorta a cg gimmie, like sun flares, that is overused and amatuerish.

There are cases to use such a look - but unless your kitchen is from an old dusty abandoned house, filled with smoke from burning dinner, or site of an alien abduction, it should be avoided. If it’s not motivated by acual causes in the scene, don’t use it. We just don’t see cases of it (to such a degree) much in real life, and that’s what we’re striving to interpret and replicate.

#12

Heh. Right, agreed. I was only going to add a very very small amount (not like what’s in the images above!), and even then, probably only if I darken the scene a little bit, which I probably won’t.
It was actually more of an excuse to write the shader for it… was curious to see if it would work. :wink: Honestly, I’m surprised that it did.

#13

The outside should look a little over-exposed (with a sky that looks white even if it would be blue when outside that day) just because we’re in a dark room where shafts of sunlight look really bright. So that would make me pick the top one. (Or you could probably edit the other one to look overly bright with a white sky if you liked the other one better.)

The skylight should be bright enough that no part of the window frame looks dark, as the upper right does now, and you can see that the shadows have a cooler hue than the direct sun. Usually it can make it pretty far into the room, too, even if it is dimmer with distance.

I think the blinds themselves could look more translucent, so they won’t be as dark. When I see direct sunlight hitting the outside of blinds, they get a lot brighter from it, and you can even see shadows from the windowframe cast through them.

The sun looks brighter on the left side of the window than the right. Maybe it is uneven just because it is a point-source coming from too close to the window?

-jeremy

#14

New update:

Fixed quite a few of the problems since the version I had last Monday (not posted here). I also turned on caustics, just for fun.

There’s still quite a few issues I’m having… I had to include a separate piece of geometry just for shadows towards the upper side of the cabinet, because I moved to shadow mapped shadows, and was unable to get rid of leaking in that area (even at 2048 resolution). It fixed the problem, but you can also kind of see the outline of the shape. I think that stray bright patch towars the upper right is coming from the same leak, so hopefully if I fix the shape a bit, it’ll get that as well.
I had fixed the dark corner in the upper right of the window frame, but lost the correction when I cleaned out some lights. So, I might have to put another light in there to correct that. Same goes for the uneven lighting on the base of the frame; that unevenness is coming from my fills, not the key.
I’m starting to get annoyed in the way that every application seems to interpret the brightness of the image differently. When I view it in fcheck or photoshop, the brightness is right about where I want it to be. When I open it up in Opera, it’s much much darker. The windows picture viewer is somewhere inbetween the two. And I know that when I load it up in my laptop, it’ll be twice as bright. :banghead:

Anyway, I’m off to do more rendering… Any critiques are welcome. :slight_smile:

#15

Regarding color profiles, make sure that Photoshop is not applying any color correction that’s different than what’s seen in other apps. This thread might help too:
http://forums.cgsociety.org/showthread.php?f=14&t=123320

Your caustics look nice and solid.

It doesn’t seem as if your lighting matches your background picture outside the window. That scene looks very hazy, but the lighting in your kitchen has almost no light from the sky or atmosphere, it’s almost all direct sun. Either change your lighting or the background picture so they work together.

The fruit looks a little glowy (as in, too bright. “glowy” is a word I hear alot in my notes at work.)

-jeremy

#16

Thanks for the link. :slight_smile: That at least seems to have cleared up my Photoshop issues. I think some of my other apps must be doing something similar as well, but I’ll have to look into it later.

Anyway, last update. I don’t think I’ll have any more time for rendering, except for maybe a slight touch of occlusion, so this may be the final one. Maybe I’ll adjust the background a touch, too.

No GI/FG/Caustics

With GI/FG/Caustics

I added a bit more to the sky fill. It at least spreads throughout the room a bit more now. I’m a little hesitant with the sky light, because I don’t want to overlight the room and kill the contrast. I was also able to fix most of the light leaking and shadow problems (except for that rim beneath the window frame - missed that one since it’s almost unnoticable until fg/gi is in there).
I think some spots around the window frame are a little too blown out, especially if you watch the shadow. The shadow is crispest on the trash can, far away from the window. That’s not right… Oh well. :shrug:

#17

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