Twisted Tree

[michael]

I can get it just fine....

[Wolfwood]

Hm, that link says "Not available".

Any idea why?

Right click on the link and save.

Don't click the link to follow it.

Stupid geoshitties.

[ykcosmo]

Nice pic. I think u can add more detail....

[3__]

sorry, couldn't help it...

I think Houdini's renderer needs some work.

-cpb

[Jason]

Very nice; indeed.

Can you tell us more about it? What type of shader? Bump or true displace? True subdivison or one level of poly subdiv? Ambient occlusion or irradiance or light dome? Raytraced shadows or shadowmaps?

[3__]

no subdivs, uses vray displace, bump mapping (for that extra sparkle)

and fairly low irradiance settings (min/max rate of -2, -2, one bounce,

25 hemisphere subdivs). I didn't have time to ply the uv's from DaJuice's

model so the maps are just procedurals.

The light is also an area light so the rendertime could probably

be reduced to about 6min with shadowmaps or raytrace.

-cpb

[DaJuice]

I like it a lot cpb. Is is micropolygon displacement, or how does it work?

In my experience Houdini's GI is very slow compared to Brazil or Vray, and it doesn't have options for multiple bounces either, which is sort of annoying. Adaptive sampling would also be nice to have.

[3__]

yep, micro-poly subdivision displacement.

not too sure how exactly but my guess is

that its regular per-face (given the consistent

memory usage regardless of what's mapped).

I find it curious that the Houdini irradiance

is so amazingly slow. Is it un-compiled script?

-cpb

[Jason]

Nope, I wager the slowness comes from very aggressive tessellation of surfaces which have displacement shaders assigned. Its possible to get ok render speeds if you're willing to take time to adjust the LOD up and down, depending on the frequency and contrast of your shader surface.

For high frequency (highly detailed) textures, you need to have a higher LOD.

I'm going to make a very quick test of rendering that tree. Give me a few minutes.

[Jason]

There is my quick test with mantra.

One soft light from the top (shadow map)

64 samples on Ambient Occlusion.

Displacement on polys (1 level of subdivision baked into that); also just a procedural; VEX Krinkle SHOP to be exact.

Please ignore the JPG artifacts, but there is a little noise which would be easy to get rid of with a bit more sampling; or bigger/better cache.

[DaJuice]

Cool Jason. Now is that 1hr 46min in the irradiance cache render or 1min 46 seconds? The way mantra prints the render times is weird.

[3__]

over an hour... how about MR or renderman?

-cpb

[anakin78z]

Cool Jason. Now is that 1hr 46min in the irradiance cache render or 1min 46 seconds? The way mantra prints the render times is weird.

It's 1min 46 seconds.

[Jason]

Cool Jason. Now is that 1hr 46min in the irradiance cache render or 1min 46 seconds? The way mantra prints the render times is weird.

Yup; 1min 46sec. Seriously.

I'll post the file.

[Jason]

Here it is;

You may have to change the output paths for the irradiance cache and shadowmap file in the lights. I put them in /usr/tmp, and could go to $HIP/ instead - for convenience.

Enjoy,

Jason

jiversen_tree.zip

[Jason]

Quite frankly, the whole scene is pretty forgiving because:

a) It's a still frame

The tree texture is high-frequency and dark.

c) Nobody knows what its REALLY meant to look like

If our trees had large, low frequency bumps on them, light-coloured and deformed slowy with a camera moving in to inspect it, we may be a whole 'nother place.

I'm sure there is a whole lot of bad sampling in there, but you can't see it in the current setup.