Totally lost...

[Karl Larsen]

Not for lack of reading as many posts as I can find, and watching a myriad of tutorials, I have no idea why in the heck I keep getting the strange ‘pattern’ on the wall and floor on the left, or the random “dirt splotches” on the ceiling beams, or the strange light reflections on the beams and ceiling…

 

I could post an encyclopedic narrative on every last setting but… 3DS Max Design 2009, mr sun and sky, mr sky portals (void spaces where glass would be in doors the outdoor light is shining through) a&d material with ambient occlusion, GI, and EV 8. Anything else I need to post to narrow down the problem please just say the word and I will post the information.

 

If anyone has any clue what I can be doing wrong or can start pointing me in the right direction to look, I can’t tell you how much I would appreciate your help.

 

PS - I hope I chose the correct forum to post this in.

 

Edited June 13, 2011 by karlar

[jinsley]

Post your FG, GI, render settings... and you will get some answers/ suggestions a lot faster.

[Karl Larsen]

 

[jinsley]

When using FG + GI combo... disable the FG bounces... they become pointless. There are a few threads around the forum on that...

 

For your FG settings, try something like:

 

Initial point density = .4

Rays per FG = 200

Interpolate over num. of points = 66

 

Leave the GI as is.

 

for you AA:

 

1/16 - Mitchell

spatial contrast - change all values to .03

 

Before you do any of this, reset the scene to scanline and then re-select Mental Ray as the render engine... and set up a basic light coloured gray material with no relfection and AO int he material over ride slot...

 

I may have missed something but try that and see if the results are better...

[neko]

 

Before you do any of this, reset the scene to scanline and then re-select Mental Ray as the render engine... and set up a basic light coloured gray material with no relfection and AO int he material over ride slot...

 

I may have missed something but try that and see if the results are better...

 

James - I agree with all your suggestions and they make sense to me, but I don't understand this bit.

 

Why would you need to reset Mental Ray ?

[jinsley]

in my experience, mental ray sometimes has some bizarre issues with noise doing with GI/ FG... and sometimes just setting to scanline and then back to MR can solve some problems...

 

Karl, I also wonder now if you have a roof modeled or if it is just a plane? Try giving the roof some thickness, maybe your sample radius is large enough that it is reaching outside of the room??? or you could decrease the sample radius...

[Karl Larsen]

James,

 

Thanks for your help. I disabled FG and the results looked like from Mars so FG is back on... Yes, roof has thickness.

 

Pls remember, I am a total beginner -- decrease the sample radius, where?, in GI???

 

I will try the reset to scanline then back to mr and see if it makes any difference.

 

Those weird bounces and dirt are driving me insane...

 

Oh ya, almost forgot - what the heck is: "for you AA: 1/16 - Mitchell spatial contrast - change all values to .03"

 

Thanks again

Edited June 13, 2011 by karlar

[jinsley]

James,

Thanks for your help. I disabled FG and the results looked like from Mars so FG is back on... Yes, roof has thickness.

Pls remember, I am a total beginner -- decrease the sample radius, where?, in GI???

I will try the reset to scanline then back to mr and see if it makes any difference.

Those weird bounces and dirt are driving me insane...

Thanks again

 

Yes, the sample radius in the GI... try those changes and let me know how it goes...

 

if you want, archive the file and email me the scene and I will take a go at it today and email you back my results... you would be able to see how I set the scene, etc... might clear some things up.

[Karl Larsen]

James,

 

That is a very generous offer - I can't thank you enough! An email will be on its way to you in about 2-minutes.

 

Thank you,

 

Karl

[Karl Larsen]

OK how do I include the archived file in a message to you?

[odouble]

The artifacts look like artifacts from a low number of subdivison samples on a portal light. Increase the subdivisions on your sky portals and see what it does.

I think your render times will sky rocket but it should clean things up.

Edited June 13, 2011 by odouble

[Karl Larsen]

I have no setting anywhere on my mr Sky Portals that say 'subdivision samples" -- but the shadow samples are set to 16.

 

I'm not looking for Industrial Light & Magic realism in any of my renders - 1. because I don't have a NASA Workstation capable of handling those kinds of renders in under 1-week render times, and 2., because most projects just do not justify the time and effort.

 

But those artifacts and that dirt looking stuff is driving me off the deep end!

[odouble]

The shadow samples/subdivision samples should be higher than 16.

64 would probably do the trick.

I hardly use skyportals for interiors as they tend to require an unbearable number of shadow samples to produce clean looks.

 

You might want to try the Final Gather + GI (Photon Map) approach without portals if you're concerned with render times because the Mental ray sky portals currently exposed in 3ds max kinda use a Brute force approach.

[Karl Larsen]

You might want to try the Final Gather + GI (Photon Map) approach without portals if you're concerned with render times because the Mental ray sky portals currently exposed in 3ds max kinda use a Brute force approach.

 

Huh? I'm a very new, old guy, with an old system - 3DS MAX Design 2009 SP1 - on an old dual-processor dual-core XEON 2.8Ghz XP Pro workstation with 2g of memory... go ahead, laugh!

 

I wouldn't know where to begin to look to read up on the FG + GI Photon Map strategy, or how to get the light shining through the windows without the sky portals.

Edited June 15, 2011 by karlar

[odouble]

Just enable global illumination under the under the Caustics & Global Illumination tab. Do not enable caustics. Check optimize for FinalGather. All other default settings under this tab should be fine for now.

The biggest optimiztion comes from making sure the photon radius on your daylight system is just enough to cover your model so its not shooting photons everywhere so adjust that.

[Karl Larsen]

GI is enabled - I just checked optimize.

 

So, I should enable "Use Photon Target" and then set a radius for the area that is to be lit by the sun?

[odouble]

Also uncheck the maximum sampling radius parameter under the Global Illumination tab and the Max Num. Photons per sample parameter from 100 to 500 which is the default. That should do it.

Edited June 13, 2011 by odouble

[Karl Larsen]

odouble,

 

Well, so far, so so... I upped the sky portal shadow samples to 64 (I think that was the biggest improvement toward losing the artifacts on the wall next to the fireplace) and made all the other changes you suggested, and went ahead and started adding materials - also changed the 2500 kelvin color on the recessed lights (suggested elsewhere) to D65 and added a faint yellow/orange filter, added lights over the living area, and reduced the output of the under cabinet fluorescent lights. Next trick is to work on the beams and try to make them look like white-washed rough sawn lumber... it's a strange old house that I just happened to get my hands on prints for so thought I would use it to learn with. The wood top on the kitchen island looks good!

 

A huge thank you, so far!

 

PS. 35 minutes to render this at 640x480 on my dusty old computer!

Edited June 13, 2011 by karlar

[Justin Hunt]

Stick with jinsley's suggestions, and increase the average photons per light. In general there is good light coverage , just not enough light detail, hence the light sploches.

 

There are two basic workflows with Photons,

 

1) Large Radius, large number of samples, fewer photons

2) Small Radius, smaller number of samples, many photons.

 

Option 1 is good for exteriors or interior scenes with not much detail, gives smooth/ softer results. Can be too bright as samples are smoothed over a large area and isn't very accurate. The large sample numbers also can take longer to render.

 

Option 2 is good for interiors with alot of detail and gives very good accurate lighting detail. Uses more memory, takes longer to calculate but renders quickly.

 

In both cases extra detail is achieved with higher FG settings. In general you want the photons to do the hard work and FG to clean up. Dont be afraid to increase the Max Trace Depth, this will allow for more light to be bounced around for more light detail.

 

 

For your scene I'd go with option 2

 

jhv

[Karl Larsen]

Stick with jinsley's suggestions, and increase the average photons per light. In general there is good light coverage , just not enough light detail, hence the light sploches.

Please remember, I don’t have a clue what I am doing, so how do I do that?

Will anything you and James suggest conflict with what odouble suggested – that I need to go back and change?

Thanks a million!

[Karl Larsen]

OK here is the scene with what I think are Jame's suggestions - though I do NOT know if I understood his AA (Sampling Quality?)settings - I set it to 1/16 minimum and 4 maximum - but I was wondering if he meant 1 minimum and 16 maximum???

 

Anyway here is the render with his settings - which took 1-hr and 9-minutes to render:

[Justin Hunt]

Not conflicting, more enhancing what he said.

 

Yes James was saying min 1 Max 16. which are typical settings.

 

A big improvement, with some good lighting detail. The ambient occlusion is a bit too strong though.

 

For this next tip, you can choose to ignore it if its too confusing.

Seeing as the sun is contributing very little to the over all lighting, you can tell it NOT to shoot photons, leaving the down lighters to use all the photons.

 

The sun is the brighters/most powerful light sorce in the scene, as such will shoot more photons than the downlights. If you open the message window you can see just how many. In this scene the downlighters are more important than the sun. Even with the sun turned off it will still be a pleasing image. By telling the sun not to shoot photons (in the light ->mentalray settings check automatic and manual off), the downlighters will be able to shoot more photons, giving more detail to their illumination.

You will still get the direct lighting from the sun.

 

On a composion note, try moving the sun so its directly behind the camera, shape of the light on the floor will help lead the eye into the room.

 

jhv

[Karl Larsen]

Thank you Justin.

 

How do you make the ambient occlusion weaker? I changed the AO distance in the material from 4-ft to 1-ft - hope thats what you meant?

 

Also, are my render times way out of whack, if you have an opinion on that?

 

Thanks very much!

Edited June 14, 2011 by karlar

[Justin Hunt]

The AO Radius is more to do with the distance objects are to have an effect. to reduce the impact lighten the AO Shadow colour.

 

Render times are influeced by alot of things so can be difficult to pin-point, Some things to look at are, setting far attenuation on the photometric lights, overly high shadow samples. Lots of glossie samples, very high FG density and FG samples.

 

jhv

[Karl Larsen]

Well I feel a little less lost thanks to all the great advise I've gotten here today. BUT- this last image took 2-hours and 3-minutes to render at 640x480... but it looks a thousand fold better than it did at the start of today, in my humble opinion.

 

Here is the result of Justin's last advise combined with James' and odoubles' earlier suggestions - this is the image straight out of 3DS (always looks a little washed out to me):

 

This is the image with the contrast adjusted in Corel Photopaint:

 

And finally, a little boost to the intensity:

 

Now on to trying to make those ceiling beams look better and making a few tweaks to the millwork and appliances, and then start adding furniture (which, by the way, I have modeled in separate 3DS files with materials applied, and looks ok under the standard lights I used to view the results in those models -- I just hope that they carry into this model without too much stress )

Edited June 14, 2011 by karlar