Modern bathroom rendering, looking for feedback/tips

[Irkie500]

Hey Everyone,

Currently this is just a hobby for me, however I really enjoy modeling and rendering my hard work, then again who doesn't? My current project is building a clean looking modern bathroom. My skills in sketchup I would consider beginner, but I am a quick learner. My skills with indigo however are very limited.

My issue with this scene is that even though it rendered for 14 hours it still doesn't have the real photo "look". I had it set at 1920x1080 5x Supersample and Bi-Directional with MLT because of the glass and all the reflective materials. My computer is no slouch either, it has some solid hardware in there.

What I am looking for from the community are ways to improve this render and future ones. Weather this comes from more efficient modeling techniques or improvements within Indigo itself, I'm all ears. I usually get my textures from CGtextures.com because they are free and I can find what I need. The issue is that they are restricted to 512x512 and tend to look grainy sometimes. Any additional free texture resources would be a great help.

Anyway I hope to hear back soon, I am exited to start making this a great scene to show off some day!

[Headroom]

I would assume that there is some form of a window into that room through which sun light enters. Those need to be covered by Exit Portals.

The value for the white of much of the scene should not exceed 70% of the max 255 value 208,208,208 for RGB should be the maximum.

Reduce the specularity (Exponent) of some of your Materials.

If there is any glass in your scene that is not visible or generate visible caustics, remove it from the scene. This also includes window glass.

[Bosseye]

The speed of Indigo is something I've had to get used to - its brilliant, but I find it quite slow. I'm running a Xeon W3530 and 24Gb of RAM which is no slouch, but once I start to add in multiple shiny surfaces and light sources into a scene, depending on complexity I regularly have to leave my machine running for anything up to 3 days to get rid of the grain. And too much grain will reduce the realism regardless of how careful you are with other things.

I might be incorrect on this, but as far as I know Indigo is CPU intensive, so no matter how many graphics cards you're running or how powerful they are, unless you have a scene suitable for running with Path Tracing (PT) which is the only tracing method that supports GPU use, then they're useless. Hence why I discounted my Nvidia Quadro 4000 2Gb from my specs above - most of my scenes are BiDirMLT meaning it simply won't be used for rendering.

Part of this speed issue is I'm sure me not optimising my scenes quite as well as I could, but there are steps you can take to reduce the issue. As Headroom says, high white values can be a killer to render times, along with poorly balanced emitter values leading to pronounced grain; heres my explanatory thread detailing the issue: http://www.indigorenderer.com/forum/vie ... 19&t=12529

Hope that helps.

Other than that, its just general stuff for realism, like ensuring all aspects of your model are correct (for example your sink in the foreground needs a bit of smoothing to make it rounded), stuff like sharp edges are rare in real life, they're more often than not bevelled/chamfered which can allow for geometry that catches the light more realistically. Theres a good plugin for sketchup that allows simple bevelling of edges - I forget the name, is probably on smustard or the official sketchup plugin site (accessed through sketchup).

Things like making sure textures do not tile and repeat obviously is a big one and ensuring you have enough detail on textures close to the camera in terms of resolution of the texture, bump mapping, exponent maps etc.

Lighting set up is a big one, a bit of trial and error with varying emitters and their power will allow for a scene that is more subtly lit and perhaps more realistic. IES lighting profiles can really help with realism as they disperse the light in patterns that will be subconciously familiar. Lots of manufacturers issue ies profiles for their lighting allowing you to choose something suitable, alternatively if you need some I have lots you can have - just let me know. Also as Headroom says above, check you don't have glass in front of light sources where its not noticeable or needed. I know lots of light fittings have glass in front of them, but if you can't see the glass in your image as your lights are nice and bright, you're just adding extra calculations to your scene which will increase rendertime.

Also the devil is in the detail, so stuff like skirting, incidental details like light switches, lamps, door handles etc etc.

Its not an easy thing to achieve, photo realism - I've never really managed it 100%, but it is achievable, as evidenced by some of the power users on this board.

[Zom-B]

Hey Irkie,

Your image looks like beeing tonemapped way to dark, raise the settings
Try using camera tonemapping "agfapan-apx-400CD" with WhitePoint E, also enable PostPro Aperture Diffraction for some nice light glow from the light sources (camera settings a critical here, same as in real world!)
Be sure to use for mirrors a specular material with transparency off and a high IOR (666), don't use phong materials for that, they render slower/noisier.
The bigger your light sources the faster your render will clean up, also try to use a few polygones for emitters as possible.
You can smooth out meshes with Indigos SubdivModifier, try it for the sink.
Exit Portals and white max @ 204 are crucial in this scene, I only can repeat that from the two previous speakers

A SuperSampling Value of 5 seems quite excessive, 3 should be fine...
Try using LightLayers for your Lightsorces, so you can see what lightsource does clean up slowest, and then you can work on that.

The speed of Indigo is something I've had to get used to - its brilliant, but I find it quite slow. I'm running a Xeon W3530 and 24Gb of RAM which is no slouch, but once I start to add in multiple shiny surfaces and light sources into a scene, I regularly have to leave my machine running for anything up to 3 days to get rid of the grain. And too much grain will reduce the realism regardless of how careful you are with other things.

I have a quite "simple" workflow to reduce this dramatically:
Render in 200% of target resolution. Also do a material ID pass.
Now after you reached a certain point where noise is still visible but don't kill details any more use a denoiser to clean up your image. having a MatID pass you can denoise every area with a different strength and filter settings.
I use Neat Image, that analyses and adapts to noise of the image. With it I get very decent results (you can try the demo!).
after you cleaned up your image reduce the image size down to the half, where your final resulution goal actually is. This last step also kills noise (its actually SuperSampling what we do here )
Doing denoising in 200% of target resolution helps you a lot preserving details and only remove the noise, the smaller your image is the harder it gets to kill noise and preserve details.

If you are skeptical about this method you could provide me such a 1day rendering and a mat ID and I would apply the described magic on it to prove you how well it works

[Irkie500]

@Bosseye

Thank you so much for all the detail you gave in your response. There are a few things I read right away that I need to change in my scene that should help speed things up nicely. For the IES profiles, would you be able to send that to me or attach the file here? I can give you my email adress if you need it. I have a couple profiles but I didn't see any that worked for that light fixture so I just had Indigo model it for me.

I happen to grab that sink from the warehouse so i'll go in and smooth it up a bit. I have the Sketchucation plugin manager installed so I dont think finding the subdivide and smooth should be too hard.

The mirror material is from the mat database, If I recall correctly it is aluminium, which they said it could be used for mirrors. Should I stick with it or make my own specular like you said?

@Zom-B

Ill give the camera settings a go when I get home tonight. I never really messed around with them too much so I always left it to reinhard or linear. Both previous options never looked the best but seemed to work at the time haha.

------------

I do have a quick question about exit portals. I followed the guide here on the site on how to set them up and it just blocks the entire window's light, instead of allowing it to pass through. Everything is grouped properly and sealed up so im not sure whats going on there. Any insights?

Once again I cant thank you guys enough, it helps a lot to just get a few tips here and there.

[Bosseye]

Happy to help

I can't upload .ies files here, but give me your email and I'll send you a few.

Also on this link: http://www.photometricviewer.com/ you can download an IES viewer which previews your profile so you can get a rough idea of what it will look like prior to linking it to your sketchup scene. I assume you know how to link IES profiles in Sketchup? If not, just expand the 'emitter attributes' property box in the SKIndigo material editor and check the 'ies path' box, then navigat to the file.

The warehouse can be a good place to get models, but there is a lot of dross on there so worth taking the time to find a good model. Often you can find better models on other sites in .3ds format and then import them to sketchup. I use this one on occasion: http://archive3d.net/

There is already a basic smooth tool in sketchup which does a good enough job for simple smoothing requirements, but its off by default I think, so have a look in toolbars or window menu in sketchup.

With regard to Exit portals, I might be wrong but I think the latest Skindigo 3.6.something, lets you assign exitportals as a texture so no mucking around with grouping and so on.

[Irkie500]

Hey thanks for the link to that 3d model site, im trying to build up a library of resources for me to use. I have been using my time at work to search for texture sites and found a few good ones, im excited to use them.

I should have some time tonight to work on improving the scene a bit. I want find new sinks, a few new textures, change the white saturation, reduce phong values and add some clutter to the scene. Ill try and get a new render up tomorrow.

[lycium]

There seems to be some subtle blurring on the mirror reflections, suggesting that it is a veeeeeery high exponent Phong. If this is the case, it will probably be better to use a perfect specular mirror, by creating a specular material and making it not transmit.

Such scenes (with mirrors and small lights) are very challenging for unbiased renderers, even with bidir MLT; most scenes will not have nearly as much trouble.

Nevertheless, we're working on some updates to MLT to make it converge faster, which should be released soon after Indigo 3.6.

[Irkie500]

Alright so i didn't have as much time as I thought, so no render to show off. I did however adjust all of my materials so none of them have RGB values past 210. I also took the suggestion and changed the mirror to a specular material instead of a phong. The metal towel holders and any "chrome" items have been changed to a brushed stainless steel.

I found a great hanging towel model but am having trouble getting a texture for it, anyone have source for that? I changed out the sink with a really nice hi res one, looks really nice. Again ill try and get a render up tonight even if it is a bit noisy.

On a side note, why is it that not matter what value lumen I put in for the emitter it does not seem to brighten the scene at all. I have 6 spot lights in the ceiling and 2 wall lights and its very dark in there. If I recall correctly the lumen value is set at 3000.

[lycium]

If you have only a single light source in the scene and use Reinhard tonemapping, the auto-exposure will compensate for any brightness increase.

[Irkie500]

Thats the problem, if I use linear or a camera setting its extremely dark. I feel like at 3 thousand lumens the lights should be brighter.

[CTZn]

Hi Irkie, the camera tonemapping model should normally be versatile enough to correct the exposure to your needs. I for one am dropping the Reinhard method at the lighting stage.

[lycium]

I do however agree that 3000 lumens should be visible in that room; I think this is a question for Ono

[Irkie500]

Ill try and add some IES profiles to the ceiling lights to see if it will help flood the room a bit. Perhaps indigo is rendering it as a straight "stream" so to speak being tucked inside the ceiling a couple inches.