Importons and Irradiance Particles

#375

Is it possible you can’t use the sky portals in max combined with the importons & IP solution?
My max keeps crashing every time I hit the render button, with portals in my scene.

Great work so far on the testing phase guys, really awsome stuff! :bowdown:

#376

Rendered some images lit by Paul’s Grace HDR via the new feature built-in IBL of mental ray 3.7, IP, and FG with Maya’s IBL node and anti-alias setting as min. 0 max. 2, gamma is 1:

  1. IBL3.7
  • Color Gain at Maya IBL is 0.317 (1/pi)
  • environment lighting quality is 1
  • FG is off
    render time is 10:50
    it is still noisy even at quality 1
    it catches the most shadows details
    the light bloom at the chrome ball reflection is stronger than FG
  1. IP
    rendered the same scene with the two-passes method of IP:
    a. IP map gen. pass
  • Importon den. 0.1, max depth 2
  • IP ray 64, env. ray 64, indirect passes 2, interpolate never
    gen. time 32s
    b. Render pass
  • IP map rebuild off
  • IP ray 512, env. ray 512, indirect passes 2, interpolate always
    IP final pass gen. time 2:33
    render time 2:39
    total time spent 2:39 + 32 = 3:11
    as smooth as FG
    shadow is darker than FG, less detailed than IBL3.7
    cannot catch colored transparent shadow or caustic
  1. FG
  • Color Gain at Maya IBL is 1
  • FG accuracy is 1000
  • FG point den. is 1
  • FG point interp. is 100
    render time is 4:29
    it is smooth
    shadow is smooth but not as detailed as IBL3.7
    it catches some caustic of the transparent torus
#377

There are some strangeness with Irradiance Particles and HDRI (IBL node) workflow: the tone of image is strongly depends of just one parameter – Env. Rays.
As follow the tutorial “Importance Sampling with HDRI” posted by dagon in this tutorial , I setup a simple scene with IBL node (the same probe_16-20_anglemap.hdr inside), plus mia_exposure_photographic and this IP settings:
density 0.02
max depth 2
Rays 512
Indirect Passes 2
Interpolate Never (actually with interpolated turned on the situation isn’t changed)
Env. Rays 64 (we will change this parameter soon)
Rebuild On

By the way, Maya 2010.

The results:

  1. Env. Rays 512
  2. Env. Rays 1024

    Ok, the difference from previous (512 env. rays) is explainable: “the environment light here has a big impact in the render quality, if you lower too much the env. rays you loose details from the HDRI (in our case, the sun contribution)” – from the tutorial.

But if we continue increasing Env. Rays, the image will continue changing.

  1. Env. Rays 1500

  2. Env. Rays 2048

  3. Env. Rays 4096

As we can see, the image’s tone varies a lot – from cold to warm. This may be not so evident when you look at this pictures side-by-side, but is you open it e.g. in different tabs of your browser and then flip it, the difference will be more noticeable.
And so what is the real tone of current HDR in this case?

Consequently, we can’t so simple use the trick of saving IP map with low env. rays and then uncheck Rebuild and rerender with high env. rays number – the tone of image will be from the low env. rays settings. I.e if we compare image with trick and without – they are defferent tone-wise.

  1. With reuse IP map trick (512/1024 Env. Rays)

  2. Without (1024 Env. Rays)

And even if we add a directional light to this scene to simulate direct sunlight, it will not change anything – the tone will still changing.

There is no such problem with Sun and Sky – the Env. Rays does not change tone of image so drastically.

And of course, I’m sorry for my English – this is not my home language.

#378

Hi, just one thing.

With later mray versions you can use IP and FG together. Yep, IP will determine the place of FG points instead to use the usual FG heuristic. It was available on the first implementation, then removed. I think I read on some early docs FG now supports IP. What mray version does use maya 2010 btw ? :blush:

cheers, max

#379

mental ray: version 3.7.53.5, Jun 17 2009, revision 88216

#380

It would be great to use FG with IP, is it available in MR 3.7? I have max 2010 and its version is 3.7.51.20 but the MR manual that comes with still says:

"Irradiance Particles cannot be used in combination with globillum and finalgathering[i]."

[/i]Should we wait for the 2011 version? :wink:

#381

Dagon started a interesting thread about IP and progressiv sampling on maya 2011. Unfortunatly I never been able to obtain a good render with IP on Max. Even in brute force mode there is always kind of artifacts in the shadows. Why isn’t there any nice Max settings or scene posted around?
anyone have a nice sample to share?

#382

Greetings to All of you!

I’m watching this thread and I love IP+Importons.

For now I’ve found two major problems with this shader:

  1. Using IP+Importons glass doesn’t pass light;
  2. Self-illumination object doesn’t affect scene.

I’m using 3ds Max 2010 Design.

Do you know how to fix these issues?

kcpr

#383

Apart form my question, I’m attaching two images, both rendered on 3ds Max 2010 Design:

[img]http://www.kcpr.pl/imgs/wizualizacje/kcpr_classroom.jpg[/img]
This one is made using mrSkyPortals (one on overy window) with source of environment, which is my self-made HDRI map. The mrSpotLight is disabled.

The settings are:

500.000 Importons Emmited
no merge
Density 1,0
Trace Depth 5
no traverse

Irradiance Particles:
1280 rays
no interpolation
5 passes
no environment evaluation

These setting are really high, rendertime is soooo long (about 2 and half hour) on my machine (Xeon 920 Blomfield @ 4200 Mhz) and STILL there are ugly light leaks...

[img]http://kcpr.pl/imgs/wizualizacje/kcpr_classroom-env-only.jpg[/img]

This one is rendered without ANY lights, only environmental HDRI (same settings of map, exposure, etc).

Settings are:


 30.000 Importons Emmited
 no merge
 Density 1,0
 Trace Depth 5
 traverse enabled
 
 Irradiance Particles:
 500 rays
 no interpolation
 5 passes
 500 rays of environment

Render time: about 28 minutes.

I'm on the beginning of the testing of these settings, so I'll post my conclusions later.

Greetings,
kcpr
#384

These setting are really high, rendertime is soooo long (about 2 and half hour) on my machine (Xeon 920 Blomfield @ 4200 Mhz) and STILL there are ugly light leaks…

I was under the impression that portals only work with the sun/sky really, and are basically FG ray focusers. I don’t believe they connect very well with IBL-type stuff, at least not in my experience…

Do portal lights in mental ray work with importons/IP? Are they designed to work that way, or are they tied to FG only? (aside from the photon/GI stuff, obviously)

#385

IP should not need a portal light. IP already uses importance sampling to find the sources of light and doesn’t need the “hint” FG requires.

#386

In my tests with IP, the scene does look better with a Portal Light. There may not be any specific interaction between the IP and the Portal Light but with only IP the scene (typical window into a room lit by Phys Sky) it was too dark.

#387

Hi. Is it possible to shoot more than 512 irradiance particles rays in Maya 2011?
the string below that must be allowed more rays in 2009 doesn’t work for me in 2011.

setAttr -type “string” miDefaultOptions.stringOptions[12].name “irradiance particles rays”;
setAttr -type “string” miDefaultOptions.stringOptions[12].type “integer”;
setAttr -type “string” miDefaultOptions.stringOptions[12].value “1000”;

#388

hello everybody…

hope someone can explain me why Traverse (found in MR Render Settings/Importons ) is unchecked and cannot even be checked ? The Maya Online Help says that the Default Setting would be checked… Plus Alex Sandri keeps saying in his 2009 Tutorial to check it…

is anyone still using the Irradiance Particles and Importons to render scenes ? there still seem to be not many Tutorials so far…

I think that the results are still the best for MR… GI + FG still look like Toy Story renderings… ??? No offense to MR but VRay Renders are somehow more photorealistic.

thx, ertan from Kaiserslautern

P.s. i was able to indirectly check Traverse by going to the miDefaultOptions Tab and type in the Value True in the String Opions (8)… Is there a way to enable it in the Render Settings ?

thx again

#389

I can’t remember what Traverse does but I love IP! I watched a short tutorial and stopped using FG completely except for Forests. For some reason FG looks better on masses of trees.

#390

Traverse will populate the scene with more importons. This is because the importons will pass through geometry on a line-of-sight from the camera and store at each point where it strikes an object.

This is unnecessary for IP but can be useful for merging GI Photons that bounce through an entire scene as opposed to just camera space like Final Gathering or Irradiance Particles.

You’d be surprised at what you see in movies that wasn’t even there, and was rendered with mental ray. It’s really up to the artist.

#391

okay thx so much guys for your really fast answers…

okay you’re right…I know what you’re saying… It’s the pool-player not the cue-stick…

thx again !!!

#392

And Alex keep saying it…:eek:

[/color]
Btw… I just touched this topic in the most extensive, annoying, “petulant” and “logorrheic” post in CGTalk history…:scream:

http://forums.cgsociety.org/showthread.php?p=7057237#post7057237

Hope it helps…:curious:

“The message I stress: to make it stop, study your lessons… Don’t settle for less, even a genius asks questions… Be grateful for blessings and don’t ever change, keep your essence…”

#393

Hi all there guys… its a veryyyy long and interesting post about ip and importons… :slight_smile: i read all the comments
I know its about ip+importons inside maya but maybe someone can help me with my problem inside 3dsmax design 2012-64bits…
Iuse render optimizer script and mr options manager script and i have problem with both scritps if i put more than 0.1 in the value of the density of the importons, in all the available combinations, only with fg+importons i can put a high value in density, like 1 or 2 and 3dsmax dont crash. In all the other combinations if i put 0.2 or more 3dsmax crash.
And another question is about fg+importons+ip, well first only works in my case if i put 0.1 in density of importons, but appears this message in many scenes where i use this combination:
“PHEN 0.5 error: A ray encountered an invalid color (NaN), using black instead”
If i use fg+importons this message doesnt appears.
Thanks and good luck!
Richard

#394

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.