Day 26

Wanted to do some test on caustics and how parameters in 'Caustic Light' and Mantra 'PBR' dramatically affects overall look & render time.

I went back to using the buddha .hip file from the previous day.

Experiment #1

The only change i made was the 'Sampling Quality' within my lights. Surprisingly, value of '1' and '10' had almost no impact on the renders.

In the 3rd image, Filter Sample parm in Caustic Light was increased to 128 from 64.

Rendering took approximately 8s more.















Experiment #2

'Pixel Sample' in Mantra.

Appears that this parm is very expensive, 3 x 3 to 6 x 6 and the render time was close to double.












Experiment #3

1st image was to see how the renderer react to photon counts. Increased it to 1 million compared to 2nd image which was 100,000 photons. Other parms remain the same for more accurate comparison.

I didn't feel it was an unreasonable increase in waiting-time considering the number of photons went up 10 folds.

Between 2nd and 3rd image, they had the same parms setting beside Reflect/Refract Limit.

Time taken was reduced by half upon lowering them to 2 from 10. Nice, doubt 10 is required in our project so this is going to help speed things up, every bit helps i guess.







Experiment #4

Diffuse Limit doesn't seem to make any changes. It may when other i am working on a heavier scene or other parms starts changing, we'll see.

1st image had 100,000 photons, typo there.











Experiment #5

Not exactly sure what 'Allowable Path' parm do or how it will help, green dots appeared after setting it to 'All paths' and render time x2.

Sorry, another typo in 1st image. It's 100,000 photons.

Hi Mr Ron, if it's convenient for you to explain. Thank you.








Experiment #6

Mantra > Render > Tile Size

Time taken as shown.




















Experiment #7








This one was more on see how Filter Sample affecting the look of caustics. Apparently it is like applying gaussian blur filter to it, they are getting less sharp and spreading outwards. (Appears more like glow effect than caustic to me)

Feel more confident about mantra and lights now, could probably answer or explain more if i am asked about various parameters.

My second time doing such experimentation, first was back in studio project as the computers had were much slower than FYP's and it had serious insufficient memory issues.

Batch renders would either abort or hang mid-way. Had to speed things up with optimization without compromising the quality, but i find it a less daunting task doing it in Houdini. Hope i aren't spending time researching at the wrong things. ><

Day 25

Days back I was rendering light instances with PBR which took between 5-15mins depending on the settings. Now i want to experiment how PBR engine fair when rendering simple scene.

Used a sphere (chrome material + skylight + motion blur).

Disabled 'Sun Light' parm unlike when rendering the terrain scene.

I was only increasing Sky Light's Sampling Quality gradually instead of Pixel Samples in Mantra.

The change of quality in the renders can be seen and the difference in rendering time wasn't big as shown in the screen capture.












Slightly heavier scene with spheres copy stamped.

Everything else remained unchanged and same tests were done on this scene.

The time taken to render these were all under 15secs.






















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Fluid simulation is part of the project, thought i should take a look into rendering caustics even though there's a possibility it won't come into play because they are rapid and high-speed fluids with motion blur etc. No harm knowing more. ._.

Peter Quint introduced the process of rendering caustics in Houdini11 via shelf tool Caustic Light.
Followed him through it and end result is below.

Haven't looked at 'Render Manager' until i was told about it by danBode from CGTalk.

No Caustics took 10secs.
Caustics enabled took 19secs.
Mmm...





You have to use it if you want to start optimizing your settings and minimize your render time. Big part of rendering phrase!

Do remember to untick 'Clear Completed Jobs' else you'll think it's broken for always being an empty list.


One other place to see render information. (Via Mantra ROP)

Slightly messy with all the text & numbers, occasionally the Console doesn't appear despite having Verbose checked. /shrug







This was a problem with MPR and indirect photon map, supposingly i should have indirect lights just like using PBR. I might had missed something, don't know what though.

Day 24

Today's thursday and Mr Douglas dropped by for the weekly review,

Mr Pang, Mr TK & Rap were also present.

He shared some rendering tips on how i should avoid upping render setting on the Mantra Node but instead up the "Sampling Quality" of the virtual lights.

That way only that particular light is affect instead of globally increasing the settings of everything in the scene.

Another thing he shared was Irradiance Cache. Suppose it will speed up renders via PBR or MPR if the Irradiance files were written out.

Will have to read up on it more.

After showing the day and night lighting, Mr Douglas was leaning to the night version, plus he doesn't mind going for stylized lighting with the use of HDR image. Glowing particles effects (aura) may be implemented. Some references suggested by both him and Mr Pang were Ominusha's aura and Percy Jackson's hydra transformation.

Another movie came to my mind, it was Disney's Enchanted where the evil queen turns into a drake, the entry really had a devilish and ominous look and the lighting, stormy clouds and lightning all seem like something could be brought into our project.

Our pipeline should focus on being production friendly and rendering efficiency. A rough margin would be maximum 10 minutes per frame (heavy scenes) but ideally a couple of minutes like 3 (lighter scenes).

We can also be involved in compositing stage if we can cope, we'll be doing it in COPs which Mr TK says is a good stepping stone to Foundry's Nuke.

YouTube Links

Enchanted

http://www.youtube.com/watch?v=GhjHNA0JjA4

Onimusha 2

http://www.youtube.com/watch?v=Y9D8WOzDuNg

Onimusha 3

http://www.youtube.com/watch?v=riUxNdk44bY&feature=related

Onimusha - Dawn of Dreams

http://www.youtube.com/watch?v=dFIvJ6QijJE&feature=fvwrel

Onimusha Transformation

http://www.youtube.com/watch?v=eBI3pR_VhJo

Mr Douglas and Rap were showing some work they had developed, details will be added later tomorrow. Hopefully i can post the video Rap sent me after i ask him.

Joined our lecturers and client for lunch this time, they chatted with us and share some ideas on how to go about work. Mr TK talked about the forums & encouraged everybody to be active, he also sneakily said Jeff Wagner (Houdini expert at SESI) was replying to Tanner's post which we wouldn't had known as the user wasn't using his real name.

Told us to take note of some ethics during our stint in California, what to expect at the office and not be stay on the streets at night and try to go around in pairs. Really feel our batch is in good hands and deeply appreciate what all of them are doing for us since year 1. :)

Hi Mr Ron, looking forward to seeing you again soon. Take care.

Day 23

Looking into light instancing, rendering 1 frame was pretty heavy even when using MPR. It was grainy in MPR but the quality was much better when using PBR.

I believe it is due to all the instanced geolights with raytrace shadow that's making it all slow. Circusmonkey on forum had a scene setup with the same instancing method, the difference was he used shader for illumination and had a HDA that randomizes the Cf output of the shader.

Examined his file, the render times were in seconds, felt it was a much more efficient way of achieving the same effects.

Here's his post although it was back in August 2010, http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=20446&highlight=light+instance

Could only see the lights that were close to the wall on the first test, this time i copied tubes to see the effects of the lights better.

PBR produces nice results with the expense of render time. And threw in the mandril image for fun.

Day 22

Picked up reference of night shots in the canyon, wanted to try match night lighting condition.



















These were using the same method i used for the sunset mood. Sun/sky light and a couple of arealights.

I prefer these renders over the sunset ones but will have to see what happens on the upcoming review with Mr Douglas.

















Forum:

Start a topic on lighting via sun/sky light and managed to get tips.

Here for more details,
http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=21947

From the thread, i was told to look at HDR images differently. Recall Mr Douglas having no problems with unrealistic stylized water, wonder if stylized lighting via environment light would be what he is looking for.

Replies from forum peeps makes me want to ask more stuff, hope i am not asking silly ones.

Day 21

Was following reference images of Grand Canyon, attempt to get the same mood.















Had a skylight using "Date, Location & Time", i keyed in the summer noon period and gave picked an orange hue with high value.

Did a couple of variations and test-rendered them in low-res terrain, here are some which i find pretty decent.

Day 20

While playing with lighting, an idea came to me on how the pillars could be modeled.









Multiple "SoftTransform SOP" were used on a Tube to control the shape of each section. Easier to get a overall desired shape.




"Mountain SOP" and AAnoise was later used. The help button showed what was required to setup AAnoise.









The whole column felt empty, attempt to copy rocks onto it. They have the same AAnoise as the column, but they aren't randomized yet.

Will try add some variables in the Stamp Tab later. Not so sure how to do it though, i do remember there's a video on basic copystamping in sidefx.com.


Spent alittle more time playing with lights. Change the time, date and location of the skylight to see the differences.














Some part of the canyon wall was over-exposed, i knew it was being emitted by the arealights nearby as i could see it from the interactive lighting in the viewport. Only figured out i had to tick "Single Sided" checkbox.



Always had the impression these lights only emit light only at where they were facing by default.