Unofficial Displacement Rendering Challenge

[eetu]

Hi all!

I ran into these nice 3delight test renders by Turin, and immediately got the urge to try and replicate them in mantra.

It has been a very illuminating learning experience this far for me - displacement, dicing, materials and all that jazz. I even found a gallery material bug in the process :)

Soo, I thought this might be a nice "challenge", I can imagine others also getting the copying urge.. ;)


RDG had a good idea; if this feels a bit overwhelming at first for some, this could be divided into 3 "levels"

- beginner level: get a basic scene with displacement working and rendered, no worries about materials and lighting
- medium level: try to copy the look and feel of the originals, or try to achieve a nice different look
- pro level: add hair and try to optimize the render times as much as possible


And don't forget to share your .hip-files for the better education of us all! :)


eetu.

[eetu]

Here's my first version:



The rendertimes got a bit high as I added raytraced soft reflections *drool*
These took 15 minutes on my macbookpro when updating shadowmaps, and ~6 minutes on a quad opteron without updating shadowmaps.

Regular micropolygons, predicing, 12x12 pixel samples, 3 shadowmapped spots, see .hip for the rest.
(Don't take the .hip too seriously, I am just learning this stuff and probably doing some stupid things..

Working on getting it cleaner and faster now..

eetu.

Attached File(s)

•  ee_dis2.zip (117.08K)
  Number of downloads: 390

[LEO-oo-]

Nice renders and good idea!

[altbighead]

I started playing because today is a holiday..
I am still working on matching the same look .
Here is my first test.

The scene is very minimal with one spot light.
Micropolygon rendering
Mantra DOF
Render Time: 481.171u 3.140s
dual core with 2gb of RAM.





Edit.. Opps forgot to attach hip file. I will do it tomorrow!!

This post has been edited by altbighead: 18 February 2008 - 05:35 PM

[mark]

good work getting a challenge going eetu. love the render too - it looks like a city

[eetu]

Ah, the bug. (Might bite someone)

If you're using reflective_displace, the s and t are not connected in
simpleDisplace/ifScaleNotZero/if_useMapAndNotNull/ - between subinput1 and texture1.

This will cause the displacement map to not see the actual geometry uv's.

9.1.155

PS: a full HD render at http://eetu.iki.fi/h...is/bigdisp9.jpg

[zasid]

Really Nice Render Eeto and thanks for the file.

[wick3dParticle]

Hey,
Great challenge!

At first I thought that this was way over my head to even try. But then I thought, eh...what the heck! So I gave it a shot...learned some new things along the way. I guess I will be entering the beginners challenge.
I will post my hip file along with a few questions tonight...because I only have my jpeg here with me.

Thanks,

Ilan

Attached thumbnail(s)

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[Marc]

Nice challenge, thanks for starting it eetu

[Jason]

Marc, on Feb 20 2008, 04:52 PM, said:

Nice challenge, thanks for starting it eetu

To throw some fuel on this fire, check out the "Re-dice Displacements" rendering property than Mantra can accept. At the cost of some speed (depending on your Shading Quality settings), it will redice long displacements and allow you to make multiple non-linear displacements. It results in your displacement shader needing to be run several times to determine displacements, but the result can be very interesting. Check it out:)

wicked3d, you might benefit from turning up your Shading Quality on your object to something like 3 or so.

eetu, cool renders!

[MADjestic]

Jason, on Feb 20 2008, 11:00 PM, said:

To throw some fuel on this fire, check out the "Re-dice Displacements" rendering property than Mantra can accept. At the cost of some speed (depending on your Shading Quality settings), it will redice long displacements and allow you to make multiple non-linear displacements. It results in your displacement shader needing to be run several times to determine displacements, but the result can be very interesting. Check it out:)

wicked3d, you might benefit from turning up your Shading Quality on your object to something like 3 or so.

eetu, cool renders!

Hey Jason,

that multiple non-linear displacements thingy has been chasing me for some time. I think I need a little push, when speaking mantra, and non-linear disp. I mean as far as I am aware, I don't see a method to change displacement direction along the geo being displaced, or am I missing something obvious? Excpet for some esoteric stuff like displacing a geo, converting diplacement to geo and displacing it again.

For now I see 're-dice' feature only as an optimisation of long diplacements, but obviously you see further than me here. Could you eleborate on that a bit more?

I.e. displacement is basically a pushing of geo elements (points\micropolygons\etc.) along some vector. Is there a way to make that vetor change along the displacement distance, in Mantra-Houdini?

========================

Cool renders btw, eetu. I suppose that hair is also done as disp in those Air renders. Is it allowed to wire render those in Mantra, since wire rendering is so fast in Mantra and can be considered as it's own cool feature?

Thumbs up!

[eetu]

MADjestic, on Feb 21 2008, 04:15 PM, said:

I.e. displacement is basically a pushing of geo elements (points\micropolygons\etc.) along some vector. Is there a way to make that vetor change along the displacement distance, in Mantra-Houdini?

I'd guess that the displacement is done along the surface normal. During the "2nd pass" the normal is recalculated from the first pass' displaced surface, and then displaced along that new one. Having some more control on the displacement direction would be nice, but it's a cool feature anyway!

MADjestic, on Feb 21 2008, 04:15 PM, said:

I suppose that hair is also done as disp in those Air renders. Is it allowed to wire render those in Mantra, since wire rendering is so fast in Mantra and can be considered as it's own cool feature?

I'm pretty sure it's just hair in 3delight, not a displacement. Go on and wire-render them in Mantra!

eetu.