instancing grass using fur or hair

[cgbeige]

do you mean Paint Effects grass? Modify/Convert/Paint Effects to Geometry. That won't make instances though - it makes unique meshes

[thehive]

yea i know , that but im looking to jus make instances hmm thanks though

[noizFACTORY]

can i replace grass or hair with geometry or is that a Shave thing?
thanks

Yes, that is a Shave thing.

[Hamburger]

yea i know , that but im looking to jus make instances hmm thanks though

once you convert a paint effects brush into geo you can then transform it to worldspace 0,0,0 - freeze it. Then open up the paint geo script and you can paint instance your grass around everywhere.

When renering in mental ray you can even attach a mip_binarybroxy shader to the grass, switch to BSP2 and you'll have fast grass that you can instance thousands of times around your scene. (Providing you have Maya 2010...Maya 2009 and BSP2 sucks!)

[royterr]

once you convert a paint effects brush into geo you can then transform it to worldspace 0,0,0 - freeze it. Then open up the paint geo script and you can paint instance your grass around everywhere.


will history still be on?

[Hamburger]

yes, you can change pfx attributes on the fly. as long as you don't delete the history on the original geo your isntancing from, it's pretty flexible.

[royterr]

yes, you can change pfx attributes on the fly. as long as you don't delete the history on the original geo your isntancing from, it's pretty flexible.

where do you choose to instance? because this is what i am doing :

create a PF grass brush
convert to poly
duplicate that poly as an instance
freeze it
then i use the paint geometry tool to paint that instance poly on a surface.
Then when i change the PF original attributes, only the freezed instance poly changes with it not the painted geometry.

have i done naything wrong?

[tharrell]

The Maya fur grass preset isn't the greatest, but you can tune it to do decent looking grass pretty well, with better control than PFX in my opinion.

Check out the green button on your fur shelf :)

Last time I tried to do grass in shave was several years ago and I couldn't get rid of the environment flicker to save my life... I'd love to hear if that's been addressed in recent updates. Haven't gotten around to testing it myself.

You could also instance polys to particles if you want a little better control than PFX.

--T

[noizFACTORY]

where do you choose to instance? because this is what i am doing :

create a PF grass brush
convert to poly
duplicate that poly as an instance
freeze it
then i use the paint geometry tool to paint that instance poly on a surface.
Then when i change the PF original attributes, only the freezed instance poly changes with it not the painted geometry.

have i done naything wrong?

The painted geometry are simply duplicates of your original mesh without any history info between them so you aren't doing anything wrong (as far as I know). You won't get to change all the painted geometry by changing your original paint fx mesh.

Instead, you could use particles, as already suggested to instance the grass mesh around the ground. If you have access to Shave and Haircut, then that supports geometry instance on hair as well and though there's no history between the shave node and the instanced geometry there either, its simply a matter of re-instancing the updated mesh to the shave node.

If you want to stick to maya tools, then you could probably try attaching paint fx grass brush to a hair system on the ground. The hair system could be static and you can use clumping properties in the hair node itself. But that could eat up a lot of resources for bigger grass fields.

The Maya fur grass preset isn't the greatest, but you can tune it to do decent looking grass pretty well, with better control than PFX in my opinion.

Check out the green button on your fur shelf

Last time I tried to do grass in shave was several years ago and I couldn't get rid of the environment flicker to save my life... I'd love to hear if that's been addressed in recent updates. Haven't gotten around to testing it myself.

Maya fur may not work out in really close up shots where the fur-like look could give away the shot. Maybe it can be mixed with instanced geometry. Instanced grass mesh for detailed blades and fur as filler grass.

There was one version of Shave last year which had an issue with flicker and that was fixed quickly. We use Shave through out our projects and usually flickers tend to arise due to poor shadow map settings or weird geometry deformations or bad sampling quality. But then we convert the shave to ribs and render in a rendermanesque renderer so maybe Software or MR renders tend to flicker more. Is there anything specific I could help you with?

-Sachin

[tharrell]

There was one version of Shave last year which had an issue with flicker and that was fixed quickly. We use Shave through out our projects and usually flickers tend to arise due to poor shadow map settings or weird geometry deformations or bad sampling quality. But then we convert the shave to ribs and render in a rendermanesque renderer so maybe Software or MR renders tend to flicker more. Is there anything specific I could help you with?

-Sachin

Thanks for the offer!

It wasn't so much a Shave problem as a "Final Gather is really really terrible for thin moving things with volume if you want it to render in a reasonable amount of time" problem... with a moving camera.... circa Maya 8.5. Looking back on it, I'd have baked the FG map, or just used a crapload of directionals. At the time I was still clinging to the "everything has to be in my beauty plate" mentality. :shrug:

About a month ago I pretty much gave up on trying to get decent looking hair/fur or Shave out of MR at all reliably (between ram, rendertime and quality issues) and I'm in love with Renderman on that count. So easy, so fast, such good quality, zero memory footprint. Don't even think I could make it flicker if I tried :)

I can't believe that Joe doesn't hard-sell the Renderman/3DL thing... there's just no comparison stability and speed wise between the RIB out vs everything else in Shave. It was a real eye opener how much better the whole damned thing is.

Maya fur looks pretty pimp in Renderman for Maya as well, btw.

--T

[noizFACTORY]

Thanks for the offer!

It wasn't so much a Shave problem as a "Final Gather is really really terrible for thin moving things with volume if you want it to render in a reasonable amount of time" problem... with a moving camera.... circa Maya 8.5. Looking back on it, I'd have baked the FG map, or just used a crapload of directionals. At the time I was still clinging to the "everything has to be in my beauty plate" mentality. :shrug:

About a month ago I pretty much gave up on trying to get decent looking hair/fur or Shave out of MR at all reliably (between ram, rendertime and quality issues) and I'm in love with Renderman on that count. So easy, so fast, such good quality, zero memory footprint. Don't even think I could make it flicker if I tried :)

I can't believe that Joe doesn't hard-sell the Renderman/3DL thing... there's just no comparison stability and speed wise between the RIB out vs everything else in Shave. It was a real eye opener how much better the whole damned thing is.

Maya fur looks pretty pimp in Renderman for Maya as well, btw.

--T

Totally agree with you. The stability with the shave>rib>render pipeline is awesome.

And yeah, even I was surprised to get really good results straight out of maya fur in renderman renderers. Deep shadows are god send.

I've posted some tips on your website in the displacement post :)

-Sachin

[royterr]

The painted geometry are simply duplicates of your original mesh without any history info between them so you aren't doing anything wrong (as far as I know). You won't get to change all the painted geometry by changing your original paint fx mesh.

Instead, you could use particles, as already suggested to instance the grass mesh around
-Sachin

so i can't do this with the paint geometry tool only with particles, right?

Hamburger, your word on this?

[SreckoM]

Yes you are right, paintGeometry doesn't create instances. Particles approach is almost same workflow. Paint particles with ParticleTool, and then replace them with instances of object. You can easily create grass filed this way. Just replace placed particles with various grass patches that you created using PaintEffects, for example.

[Hamburger]

paintGeometry does instances.

I've attached a scene, the original bush is at 0,0,0. The rest are scattered via the geoPaint tool as instance and you can change the bushes all at once via the pfx node.

[noizFACTORY]

paintGeometry does instances.

I've attached a scene, the original bush is at 0,0,0. The rest are scattered via the geoPaint tool as instance and you can change the bushes all at once via the pfx node.

Oh right, you need to turn off the "Duplicate" option in the paintGeometry tool options!

-Sachin

[SreckoM]

Ahhh I didn't realize it too, sorry for my statement from above that it doesn't..

[royterr]

paintGeometry does instances.

I've attached a scene, the original bush is at 0,0,0. The rest are scattered via the geoPaint tool as instance and you can change the bushes all at once via the pfx node.

works great!

i remember once i was painting objects on a poly sphere, and they would stand on the sphere following it's normal directions, but when i try it know they are aligned just like the original object and don't follow the normals, any ideas?

[noizFACTORY]

works great!

i remember once i was painting objects on a poly sphere, and they would stand on the sphere following it's normal directions, but when i try it know they are aligned just like the original object and don't follow the normals, any ideas?

Turn on the "Align" option in the geometryPaint tool options. That'll align the instanced geometry to the underlying surface normals.

-Sachin

[InfernalDarkness]

Amazing, Hamburger... I knew such things were possible, but was never able to make it work! Thanks so much for your help and example scene.

[royterr]

is it possible to instance FUR in a way?

[noizFACTORY]

is it possible to instance FUR in a way?

You mean, have a few original fur strands which are then instanced around using particles or the paint tool? Using renderman, one could use rib archives to do it easily. Don't know if it'll be worth doing so in maya though.

-Sachin

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