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very large grass field??


erkutacar
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i use iray and hardware is: i7 2600k @4.5ghz, 16gb ram, quadro 5000

 

I suspect that your bottleneck is iray. Your entire scene must fit in the RAM of your video card, which I think is only 2.5GB for the Quadro 5000. I know Jeff Patton has been using iray quite a bit, so you may get some suggestions from him. Check out his website, he has two posts regarding using iray for exteriors which may help you a bit. Be sure to read the comments on both posts, he goes into more detail there.

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yes i know, and i need one with a good displacement map.. ive downloaded one from jeff patton and it looks great in the preview but once u load the material there is no displacement map.. some gradient maps for the fall offs.. here is the preview image

[ATTACH=CONFIG]44913[/ATTACH]

 

That material is just for the texture of the grass blades. The actual geometry for the grass blades in that image was generated with the Grass-O-Matic plugin.

 

Whenever I do a large area of grass, I make a few different sized patches (12 inches diameter, 36 inches diameter, 72 inches diameter), turn them into mrproxy objects, then paint them as instances using the Object Paint tool. I end up with a scene that has 10+ million polys, but since most of them are instanced proxies, it doesn't matter. I have 12GB RAM on Windows 7 64bit.

 

Here's what one of my scenes with proxy grass looks like:

[ATTACH=CONFIG]44915[/ATTACH][ATTACH=CONFIG]44916[/ATTACH]

 

its not iran, coz if it exceeds the gnu ram, it switches to cpu and actual ram.. and it does the same in vray or mental ray..

 

If that's the case, then it sounds like your grass and tree geometry isn't instanced, or the proxies might not be set up correctly. That's about all the advice I can give without looking at the scene. Could you zip it up and post it somewhere? You mentioned your system specs, but you didn't mention whether you were running 32bit or 64bit. I'm assuming 64bit since you have so much ram, but a 32bit system would be one source for running out of memory.

 

As far as using displacement for grass instead of geometry, I've never had much success with displacement grass, so I don't have any advice what the best way is. Ramy Hanna came up with a displacement shader for mental ray a while ago that works for him, so you might try that.

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Hmm i assumed it was displacing the mesh, never thought of it to be for the blades.. U r right the problem might be my proxies.. Ill make the proxy again and see how it goes.. And yes 64bit win7ult and 64bit max.. Im not home atm.. Will be in couple hours.. I will let u know it turns out

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ive made the proxies again but same result.. i managed to get a decent looking grass field with hair&fur by selective planting.. ive selected only the polygons which would be visible and also discarded the lover part of the land and covered it with soil material.. ill make it paintball area.. so ive saved about 50% of surface and managed to get 600,000 hair.. i still need about 8-900,000 for a more natural look.. the material i applied looks too light, ill change that in PS.. here is a render: (its 1920x1080 so u might wanna view in full size)

[ATTACH=CONFIG]44928[/ATTACH]

i just downloaded grass-o-matic but ill try that tom.. its 7am here and im dead tired :) thnx for all the help everyone..

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hey scott, this is a low poly version that has 500 blades and 3 segments for each.. the distribution object is 100cm by 100cm which is 2/3rds of ur object.. but still it doesnt look as dense as yours.. more polys smaller patch but less density :) it doesnt make sense :) how wide did u make the blades? and how tall? mine r 9cm by 1cm..

[ATTACH=CONFIG]44934[/ATTACH]

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oh at last :) i managed to get proper grass my low poly blades like u said scott.. in total less than 800,000 polys (unless a plane has 2 seperate polys for front and back.. it may be a trick that max does... mirroring the poly to form heightless plane, coz u cant remove a face of a plane) :) any ways.. the whole scene takes about 10gb and here is a draft render:

[ATTACH=CONFIG]44936[/ATTACH]

thank you all for the support and patience :D

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The thing you have to remember is that more than likely you'll see these patches at an angle so they can be pretty sparse, if you were to look top down on mine you would see some gaps.

 

I create my patch by making 3 different blades, then using particle flow to scatter them around the 5x5 plane. You set the particle system to generate "x" number of blades, I used 400-600 depending on the needs, and you can also set the particle system the keep the particles (in this case the grass blades) apart to prevent clumping. Then you freeze the particle system and convert that mesh into a proxy.

 

It helps when you are testing to always use a grass texture on your base plane too. Using white or gray makes the patch look much more sparse than it really is.

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It's easier because you can set the particles to keep apart so they won't be placed within a radius of each other. This prevents clumping that any scatter tool tends to use and gives you a far more uniform spread of blades. Even area scatter tends to clump blades.

 

All in all, it depends on if you are familiar with Pflow or if not if you have the time to learn it. It's not difficult, but it's not something to pick up in the flow of a project.

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yp maxer is right use mrProxy to create mesh proxys and scatter them using programs like carbon scatter

 

i prefer displacement using normal maps it is good indeed with low mem requirements but if u need detailed look chk for VUE software it is awesome, used in Avatar as well cheers!!!!! :cool:

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my mem isnt low its 16 gig.. but i used 8 blades scattered over 50cm x 50cm plane then converted to editable poly.. i made a mrproxy of that object and i scattered that about 28000 times.. (face centers of all polygones) over a 100m x 70m plane.. anyways ive sorted it out.. thanks for the replies..

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my mem isnt low its 16 gig.. but i used 8 blades scattered over 50cm x 50cm plane then converted to editable poly.. i made a mrproxy of that object and i scattered that about 28000 times.. (face centers of all polygones) over a 100m x 70m plane.. anyways ive sorted it out.. thanks for the replies..

dude 16 gig of mem is too much u can create a jungle !!!!!!! u ll need a technical assistance :D to max u r output

Edited by NeWAcEiN
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