Hair for Grass

[AkaKico]

Man... even second I see stuff from this, the more I see I can't wait to buy it. 9.5 here I come. (fantastic hrass by the way!)

[jackb602]

That grass looks great TinRocket, especially the second example. How does Hair handle large fields of grass, say 1,000 square feet or more? Is that a realistic use for the Hair Module?

Jack

[tinrocket]

That grass looks great TinRocket, especially the second example. How does Hair handle large fields of grass, say 1,000 square feet or more? Is that a realistic use for the Hair Module?

Jack

I've not done a field of grass, but I think it is a very realistic use -- there is not much difference between a field of grass and a fur coat. You can have render-time-only hairs if memory becomes a problem, iirc.

[lllab]

hi all, impressie grass,

but

1)for real thing, could anybody test a realy grassfield, i mean abig one about 100x100m with dense grass on it, just like it is in any park or green hill?

2) very important- does it render in FRstage2, is it geometry?

if it does this fast and also in FR i buy it:-)

congrats maxon,
cheers
stefan

[Per-Anders]

you can get it to generate real geometry if you want (and instantiate geometry, even "real" grass blades), which will render in fR, however fR wont recreate the hair shader (there's no hair shader in fR). you'd do better to render them as a seperate pass in c4d to take advantage of the speed and shading if that's what you want.

[TimC]

That grass looks great TinRocket, especially the second example. How does Hair handle large fields of grass, say 1,000 square feet or more? Is that a realistic use for the Hair Module?

Jack


Here's a field of grass. The flowers are instances using hair too. In fact everything in this scene is made of hair.. For the grass alone, I used 1 million hair strands.

http://www.hypa.tv/tims/misc/hairyHill01.jpg

http://www.hypa.tv/tims/misc/hairyHill02.jpg

cheers
Tim

[lllab]

ok- very cool:-)
guess i pay the 215€...

but i would like to test it first myself, srek said the demo is at maxonpage- but i cant find it???

cheers& thanks

stefan

[Per-Anders]

you have to download the 9.5 demo, it's in there.

[njack]

I keep getting "not enough memory" message if I use more than 100000 hairs, does the cloning add to the memory required? and is there a way to work out how much memory a scene may use?

[obeardy]

I keep getting "not enough memory" message if I use more than 100000 hairs, does the cloning add to the memory required? and is there a way to work out how much memory a scene may use?

How much ram do you have? 100,000 hairs is not much, how many segments per hair (the default is 12)? 100,000 hairs at the default 12 will cost around 18Mb for the hairs (compared to 84 Mb for using flat polygon based). All hairs are stored in memory for speed, styling and the hair ray tracer, if you cloned them 10 times you'd need 10 times the memory (so 180 MB for the 100,000). You can use the "Fill Hairs" these are purely render based so cost only the render drawing memory, but fill hairs do not work with the hair ray tracer (as they're not stored). If you wanted 100,000 hairs you could create 10,000 and then 90,000 fill hairs. Fill hairs are directly interpolated from the main hairs during render.

As for memory use, you have the memory for dynamics, guides and hairs. Then you have memory for the hair raytracer (if its enabled), then you have memory used to render the hairs, they are done pre-main CINEMA render into a volume, this costs some memory depending on the amount of visible hair. This can be reduce by using the Line render option so split the pre-rendering of hair so its done during the main render.

Making any sort of estimate of this lot is impossible and the hair memory itself is small.

If you need millions of hairs then fill hairs give an easy way to do this without costing memory.

With the combination of fill hair and line rendering you could render millions of hairs in very little memory. I've done 10 million and not broken much above 100Mb.

[njack]

Thanks for the clear answer. I think it was the clones that were messing things up for me, I'll have to give the fill hairs a try.

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