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Photons in a large neo-classical room

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post-193-13269393858191_thumb.jpgHi all,

I am back to this big neo-classical room and using photons to give it a realistic illumination.

The room is about 1400 EI units long and 550 EI units high (I've figured out these are basically the dimensions in inches).

This lighting is with a light object that covers the bands of windows in

the roof, and a second light object covering the side windows. Each light object is basically a group of objects placed very close up to window openings.

I like the light levels and the coloration, but it's looking a bit like an Impressionist painting right now. Is this noise?

Lookup Rad is 40. Number Photons is 500K. Intensity is 4.0.

Direct illum from sun doesn't come through due to depth of roof structure.

Any thoughts would be most welcome!

Richard

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Hi Richard,

I would say the general illumination looks really good.

Make sure you have a large number of rays being cast in your area light settings (for this scene you may need a few thousand)

I would also use a lot more photons, at least 2 million.

Then use the "bake/ database" feature to smooth the noise.

Please continue to post your progress with this project!

Dave

Please continue to share

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Hi Dave et al,

This is where I am... adding models like columns, furniture, platforms. It's about a million polygons now.

There are four lights in this scene, all using photons.

1. Roof Light Object (skylights): area light/ray count 2000-900/Intensity 2.8/photons 2500K baked/Direct rad 6

2. Wall light obj (windows): area light/ray count 2000-900/Intensity 2.0/photons 2500K baked/Direct rad 6

3. High light above cornice one end: radial light/Intensity .1/photons 400K baked/Direct rad 6

4. High light above cornice other end: radial light/Intensity .1/photons 400K baked/Direct rad 6

The reason for high radial lights above cornice is to try to gen some shadowing underneath the cornice to bring it out more.

Dave, adding lots more photons took away almost all the "noise," but I noticed as I added lots of objects, some of the noise was coming back. Would this be right? More polygons requiring more photons?

Confusing thing: I have tried many times to add sunlight to create direct shadows coming through roof using a parallel light. I can never get this to work unless I turn off the roof surfaces. Is my "sun" direct light being blocked by the "light objects" at the windows and skylights? I have masked them as transparent at the diffuse channel, but that light just doesn't come through into room. ?? Intensity of that was 3.0 and it was 3000-4000 ei units away.

Still need to add gas lanterns (more tiny light sources) and lots more funiture to this scene...

Thanks for taking a look. I'd like to know why sun light shadows don't come though! Curious.

Rich

post-193-13269393859141_thumb.jpg

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Rich

Do you have glass in the windows in the roof? If so, you will need to tell those objects to not cast shadows if you want your sun to shine through. Alternatively, you can add raytrace transparency to your glass and it will give a shadow taking on the colour of your glass(object shadow left on this time.) This will give a render hit, and may not be what you need in such as scene.

Also, if you would like a soft shadow to this direct light, it will need to be a spot light rather than a parallel.

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post-193-13269393873494_thumb.jpgpost-193-1326939387563_thumb.jpgpost-193-13269393876522_thumb.jpgpost-193-1326939387735_thumb.jpgThank you Tom and Mr. Smith!

I did accidentally have "glass" embedded into my .fac for the framed light openings. So I removed that glass (turn it off) and was then able to get Parallel Sun to go through... ONLY when I turned off the roof thickness and the Sun only had to pass through the plane of the ceiling. Here are some images to demonstrate. Room is lit by four lights shooting photons plus sun. When the lightbox frames are turned on, Parallel Sun is stopped, but it shouldn;t be. It should be diminished but not completely stopped.

I will try the idea of spot lights, Mr. S ! Yeah, I think direct light should be softer.

I'm using 3000K photons each in the two main light objects, one light object for skylights and one light object for windows. I have these objects Diffuse set at "transparent" but full Luminance. When I make them Transparent in Transparency tab, they completely disappear.

Thanks! Rich

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post-193-13269393878105_thumb.jpgHey all,

I'll try to do that, Tom! It's almost a million polys. Will assemble an abbreviated version...

Most recetly, I told the "Sun" to "exclude" the skylight framing and roof material and it all came out on one render... I do like the light levels in here. This is TWO area object light sources casting photons, TWO small radials casting photons, and a sun casting parallel.

Next will add fireplaces, railings, argand lamps, more furniture, possibly sculptures...

Rich

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Argand lamps are a must of course... I had to look it up you know:huh:

My knowledge of oil lamps was limited to the one I use during power failures... ( it has a cylindrical wick...)

Nice work Richard. The furniture will establish the size of the building. The lighting is improving with every new post, your persistence is commendable!

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Thank you very much for the compliment, Richard. You've helped me with problems many times

and I appreciate it. For me, banging my head against wall usually works over the long term. You're

right about the scale. Small glowing light sources around room with other smaller features will add interest, bouncing light and scale (I hope). Polished mahogany will add some reflections. Thx again! Richard

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I hope to post a couple of recent renders of the Large Neoclassical Room later today... but I had a general query, and see if I'm getting this right.

1) I do a render using: Always-None-Always (mode-baking-calc)

shooting photons with GI off. Results good.

2) I do a render using: Always-Database-Always with GI off. Results

good.

3) I do final render using: GI secondary-Database-Always with GI

on 1 bounce only (no sky)

The results are looking good, which I will post later today... but I just wanted to ask at what point is the bouncing light data being stored? At

the (2nd) step? Question1: If I then add objects, should I go back and re-shoot the photons (I'm thinking I need to do this). Question2: If I change textures at step (3) I don't need to re-shoot the photons because that info is stored in database, correct?

Thanks everybody! Richard

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So a corollary question is this: If I have shot the photons and the light data is in the database, if I adjust a light level or add a light, I should turn GI back off and go back to the Always-None-Always and begin again?

Thx,

Rich

I hope to post a couple of recent renders of the Large Neoclassical Room later today... but I had a general query, and see if I'm getting this right.

1) I do a render using: Always-None-Always (mode-baking-calc)

shooting photons with GI off. Results good.

2) I do a render using: Always-Database-Always with GI off. Results

good.

3) I do final render using: GI secondary-Database-Always with GI

on 1 bounce only (no sky)

The results are looking good, which I will post later today... but I just wanted to ask at what point is the bouncing light data being stored? At

the (2nd) step? Question1: If I then add objects, should I go back and re-shoot the photons (I'm thinking I need to do this). Question2: If I change textures at step (3) I don't need to re-shoot the photons because that info is stored in database, correct?

Thanks everybody! Richard

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Ola Rich!

I do my final renders as GI & Secondary-Database-Permanent with GI on 1 bounce only, so, Camera will create Permanent caches to Area Light, it speed up, because Camera dont need to re-calculate several times the photons.

Normally, on my tests, to speed up, I change my GI Window Primary rays to something like 50 and turn off the Render Anti-Alias, so, I can change lights and other details, but I still use all Area Lights as Permanent caches.

I did this tutorial here, take a look:

http://www.eias3d.com/forums/showthread.php?tid=548&highlight=Photons

Hope that helps

Thanks

Tom

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Ola Tom,

I tried to send my photons to file as "permanent" last night and I only got "camera error" messages. The ten rendering cameras are on a Mac Pro Nehalem connected w ethernet. Should I have put the .phm folders in each Renderama Camera Folder? I was a bit confused. But since I needed to send this to someone today I rendered using "Always."

I like the Parallel Sun, but as Mr. S pointed out, I can get a "softer" sunlight using spots. But the idea of setting up 15-20 Spots in place of a Parallel seems daunting. Maybe a gigantic Illuminator?

It also would be nice to get illuminated dust motes, but I figure this I can do in post-prod in Photoshop. Like streams of light...?

Here's the latest pic as I continue to add elements. Lately I painted a carpet pattern and modeled the curtains in FZ.

Any tips or advice would be greatly appreciated!

Rich

Ola Rich!

I do my final renders as GI & Secondary-Database-Permanent with GI on 1 bounce only, so, Camera will create Permanent caches to Area Light, it speed up, because Camera dont need to re-calculate several times the photons.

Normally, on my tests, to speed up, I change my GI Window Primary rays to something like 50 and turn off the Render Anti-Alias, so, I can change lights and other details, but I still use all Area Lights as Permanent caches.

I did this tutorial here, take a look:

http://www.eias3d.com/forums/showthread.php?tid=548&highlight=Photons

Hope that helps

Thanks

Tom

post-193-13269393884621_thumb.jpg

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Ola Rich,

AWESOME RENDER!!

1) When you change the pop-up to permanent, you will see this window:

post-4-13269393885709_thumb.png

2) The first button at your left is the “new” button, click on it

3) Choose a name like “Light 1.phm” and click the save button, you need to save this Cache inside the Photon Maps folder on your EIAS 8 software folder.

4) Dont forget to hit the “OK” button, otherwise, the cache will not be saved.

5) Its done, do it in all your Photon Lights which you have in your project.

Having your lights as “Permanent” will speed up your render tests.

Message me

Thanks

Tom

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Ola Rich,

“I like the Parallel Sun, but as Mr. S pointed out, I can get a "softer" sunlight using spots. But the idea of setting up 15-20 Spots in place of a Parallel seems daunting. Maybe a gigantic Illuminator?”

A Illuminator will waist a lot of Rays, because, only a few will cross the windows (Raytrace) and slow down the render.

I like Parallel Sun too, lets see what will happen soon.. :)

Thanks

Tom

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Oh this is great, Tom, thanks! I was trying to save it to my projects files, and it probably didn't recognize that location... I will try again.

Thank you for the incredible compliment! Coming form the Leonardo d'EIAS himself (well, plus Cristobal) is incredible!

More to come, as I try to add sculptures (these I am making with clay

and will 3D scan) and the oil lamps...

Best,

Rich

Ola Rich,

AWESOME RENDER!!

1) When you change the pop-up to permanent, you will see this window:

2) The first button at your left is the “new†button, click on it

3) Choose a name like “Light 1.phm†and click the save button, you need to save this Cache inside the Photon Maps folder on your EIAS 8 software folder.

4) Dont forget to hit the “OK†button, otherwise, the cache will not be saved.

5) Its done, do it in all your Photon Lights which you have in your project.

Having your lights as “Permanent†will speed up your render tests.

Message me

Thanks

Tom

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post-193-13269393967634_thumb.jpgHello friends,

Just wanted to say, I was kind of rushing in August to finish a couple of renderings (EIAS!) for an article I wrote that was published at the Ecole Polytechnique in Paris, FR. Article posted here: www.cgcapitol.org

To see the entire journal, google "Libellio d'Aegis".

I am currently making the allegorical sculpture for the room, but I am doing this with clay. The sculptures will be 3D scanned by a Princeton professor and I will insert into model and re-render. I have enclosed a progress photo of clay, as you can see, there's no way I could make this digitally.

Hope you like it, more to come I hope!

Rich

Ola Rich!

Awesome improvements :)

Thanks

Tom

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First and foremost, I would like to say this is amazing...

I have to say, personal taste tells me I actually really enjoy the look of the noise from low ray-count in the renders :D

Also, adding a tiny bit of Sub Surface Scattering would really bring the columns that little bit more realism... But sometimes EIAS's implementation can be a little tricky to get the right effects.

As for your sculpting, that is superb... I love seeing people making real sculptures still... But, you have to try learning pixologic's Z-Brush. Your comment about 'there's no way I could make this digitally' kinda made me cringe a little :P

A quick google brought up a Z-Brush sculpt... and tutorial!

http://www.scott-eaton.com/2008/upcoming-tutorial

If you can sculpt like this with clay... With a little practise, you could be making things even better, more quickly, the digital way... Look at me sounding like a sales-man. :blush:

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Tom, Thank you so much!

BJM, Thank you so much for the good word! I also like the slight noise, but I wasn't quite sure how to adjust. When I went up to 3,000,000 photons (or thereabouts) for the four area lights, it got a lot sharper. Should I also be increasing or decreasing rays in the GI?

I would like to try Z-Brush. I did make the column capitals using FZ and Silo. I will look into that. I have seen

tutes and it is almost like painting 3D. Could be a massive time saver.

Thank you again for the confidence boost. More later.

Richard

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Ola Richard,

You have 3 Parameters which you can balance to achieve better renders, Area Lights Primary Rays, GI Window Primary Rays and Photons settings.

How many rays are you using in Area Lights and GI Window?

Thanks a lot

Tom

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