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Unofficial Displacement Rendering Challenge


eetu

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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.

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Here's my first version:

untitled14.jpg

untitled15.jpg

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.

ee_dis2.zip

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I started playing because today is a holiday..:D

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.

post-602-1203371640_thumb.jpg

post-602-1203371657_thumb.jpg

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

Edited by altbighead
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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/hexadis/bigdisp9.jpg

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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

post-3257-1203550407_thumb.jpg

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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!

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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!

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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!

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.

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What I do is I use multiple displaceAlongNormal nodes, chained together - kinda how you'd do it in SOPs. I'm sure we could come up with a more obvious example (like look at IDgloop, Ivan DeWolfs non-linear displacement shader - which I haven't seen rendered with Mantra re-dice yet actually)

Anyhow, here is a little pic-

post-4-1203611089_thumb.jpg

post-4-1203611096_thumb.jpg

post-4-1203611103_thumb.jpg

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What I do is I use multiple displaceAlongNormal nodes, chained together - kinda how you'd do it in SOPs. I'm sure we could come up with a more obvious example (like look at IDgloop, Ivan DeWolfs non-linear displacement shader - which I haven't seen rendered with Mantra re-dice yet actually)

Anyhow, here is a little pic-

Oh, wow... no words. A moment of Zen again. Now everything is crystal and clear, but... I couldn't even suggest that mantra actually displaces the geo every time it sees 'Disp along normal'... I kinda de-facto assumed that it will displace the 'sum of everything' that it sees in the disp shader... wow.

Thanks Jason! It's the whole new world to play with actually!

Somebody wants to beat up those puny Air renders? now ;)

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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!

Wow Jason! Thanks a lot...That made a huge difference.

I am going to do some looking in to the re-dice.

Thanks for the tip!

~Ilan

post-3257-1203638413_thumb.jpg

post-3257-1203638464_thumb.jpg

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Now _these_ are what should be on the splash screen!

yeah - lovely work guys! also agree with peter - lets have dynamic splash (as an option of course) with the best render submitted to sesi changing every 6 months...!

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