Evermotion room - help!

[barnabythebear]

Hiya all,

I wanted to try an interior render so I'm playing around with this evermotion scene. I get a bit stuck about the relationship with between photons and GI, I also can't seem to get glass and reflections to render properly without switching on GI secondary rays. Any help would be greatly received :-)

ta

nige.

[Igors]

Hello Nige

It's a typical room scene. Create Area lights for windows, setup their quadratic dropoffs and photon params. Use more photons (like 2 millions per light). Turn GI off (for a while), specify "Always Visible" map mode. Play with map settings until you get a draft illumination you like. It's 3/4 of all work, the rest is easy: turn GI on and set mode "GI & Secondary". But don't hurry with final render, take care of good photon illumination first.

Good luck

[barnabythebear]

Hiya Igors,

Thats sort of what i've been doing, though with a lower number of photons than you suggest. I'll post the 'Always visible' version with the adjusted photon count when i have a moment.

Thanks for the assistance,

nige.

[barnabythebear]

Hi all,

Here is the photon map; i'm not too sure how to tell a good one from a bad one :-)

Here is the render with GI. Note the difference in the glass. It has a black cast too it now. Also, the illumination of the back wall looks very different.

The original post has only one area light that covers the three windows on the left hand side. In that set-up you can see that the illumination of the back wall is more predictable than with three area light, but the glass is still not rendering clear.

Thanks in advance,

nige.

[Igors]

Hello Nigel

Speaking technically this photon map is quite acceptable. Blotching is not dangerous because anyway GI averages collected reversed illumination. Bake the map (if it's not baked yet). Edges and corners should not be darker. Of course, more shadows or less etc - all this for artist/taste, it's controlled by lights' intensity, dropoff and bouncing settings.

About transparency artifacts. First off check them with only simple light with shadows. If Ok, check photon maps settings (should be "GI & secondary". If nothing could help - please simplify prj and upload to BugsTracker here :rolleyes:

[barnabythebear]

Hiya,

OK, geting there I think..... :-)

There are a few blotches lurking in corners....is this a matter the photon map or the rays count? The photon map is 5million and rays for the area light an GI are both at 900. Also, is there a way to get more contrast and slightly deeper contact shadows?

Many thanks

nige.

[RichardJoly]

Getting there all right! And doing great.

More knowledgeable people will probably chime in with suggestion for the lighting setup but, looking at the thickness of your glass table, I think it's missing refraction. What index did you use?

[Tomas Egger]

Hey barnabythebear!!

Your render JUMPED from quality!!!!

Use your Dropoff now:

1) Enable Show Dropoff check box in the left collum of Area Light UI

2) If you are using 100% of Ref, Play with a smaller number, like 50%

3) You can balance Intensity value on general tab, using a smaller value and increasing the Over Intensity value on Dropoff tab which means, you make the light closer to windows more intense and let the corners darker.

You are mastering Photons barnabythebear!!!

Then, the second trick will be balance Photons Emissions, Area Light Rays Counts and GI Primary ray Count to have a high quality and a faster render.

Thanksss

Tom

[Mark Johnston]

Hi looking alot better go Barnabythebear

Mark

[RichardJoly]

Check the refraction index of your glass, I suggest 1.52 (common)

Here is a PDF of various refraction index from Robin Wood:

http://www.rdnmultimedia.com/eias/Refraction_index_of_Various_Substances.pdf

Robin Wook link:

http://www.robinwood.com/Catalog/Technical/Gen3DTuts/Gen3DPages/RefractionIndexList.html

[atlantis23]

Just for the sake of completeness...

there's a similar IOR list in the Animator manual (appendix B).

[Igors]

Hello Nigel

About edges/corners blotching

a) increase (baked) photon map quality as possible

b) if you use "Light Customize" - do this only as "final polishing", it would be interested to see the image without any customize (if possible)

About contact shadows. As we see the shadows are enough dark/contast but glass objects look "fly off". The attachment is an approximate glass material setup (just for our taste). Of course you need to use subtractive color filter for colored transparent objects. Also: if there is an ability to make the round table a bit less transparent - it could make life easier. Because "transparent on transparent" - where a shadow comes from? :rolleyes:

[barnabythebear]

Hiya all,

Thanks for the input guys!

I tried to play around with the settings as per Thomas' post, but found that the white walls weren't as clean. This image has the same settings as the previous post but with over intensity at 2.5 and photon map at 8million, bounces at 8. I think having white walls isn't helping! The glass is from the Igors recipe.

I don't think there is a noticeable difference in terms of quality, but i prefer it.

ta

nige.

[Tomas Egger]

Hey Nige,

Blotches on dark corners and glass improved.. :) Really cool

Render time??

Thankssss

Tom

[barnabythebear]

Hiya All,

One last version, I don't want to bore you all! :)

Render time was about 90mins using a single core on my 2.66 Macbook pro

Thanks

nige.

[RichardJoly]

That's a beautiful one. I think you got a nice balance overall. Thanks for sharing!

[Tomas Egger]

Ola Nige,

BETTER & BETTER!!!

You are ready to do any Photons render.. Congratsss

Waiting new cool images.. :)

Thanksss

Tom

[Buggsy]

Hi Nige,

Thats a very nice scene/model and rendering. Are they all your own models or a composition of purchased/free models? Love the stainless steel table legs material and their shape! Table glass looks really good too. Curtains at the rear are great. How did you do them?

I think your scene is really good and only needs a small amount of refinement to make it excellent.

Just some comments on elements in the scene. Please don't take offence, I love the process of resolving what are the missing attributes when refining renderings:

Green plant in the back right appears overly green.

Top of wine bottle appears too clean and white. I drink a little wine and most wrappers on the top are coloured the same as the bottle or silver or even more mature colours rather than white.

Red chair material looks too pretty and clean. Can't tell if they're leather or vinyl or something else.

Floor texture too repetitive and out of scale.

Floor mat in front of couch flat and not sure if it is a rug?

Timber material of rear french doors not convincing.

Some atmosphere fog and light rays enabled would add mood.

Multiple light pendants in varying lengths would feel right.

The cushions on the couch at the rear don't look right.

Maybe some magazines on the glass table at the rear?

Keep up the great work. Nice to see other users exploring the new v8.0 features.

Michael

[barnabythebear]

Hey,

Thanks for all the comments guys!!!

Michael, i agree with all of your comments! These will be corrected at some point :-)

The scene is pre-modeled and originally came in Max/Vray flavour. I just wanted a nice looking room scene to jump in with and start experimenting :-) There are nine more scenes on the disc to follow! Ultimately i will model the rooms and some of the furniture etc but use pre-made content to flesh out a scene.

I'm currently vacationing in Japan right now but i want to do some more when i return as this type of scene is something that I haven't attempted before and they are are good fun.

ta

nige.