Grass Test using particle flow and MR

[Dave Buckley]

I also disagree with what you said about too much contrast, based on camera/sun position they'd be pretty dark anyway

[jinsley]

No problem mate. Well for starters this screams 'making of'

 

Even the raw looks nice. So everything is 3d and then sky and colour adjustements in post?

 

Any inspirations for the final look? Reasons for the colour adjustments? Did you take the sky photo yourself? How many different patches of grass, long, short, patchy, clumpy etc? Methods of grass patch placement? Different render elements used? Daylight system or hdr?

 

The list doesn't stop there

 

Anyway 6 months have paid off, job well done

 

yes, everything is 3d... i think there are 1 or 2 hundred objects and then alot of proxies. All materials are influenced heavily by Peter Guthrie and his blog, but with a mental ray twist to it... I also spent alot of time in the beginning reading Ramy Hanna's blog. I used Pixela's method to quickly place the majority of proxies:

 

pflow - bake pflow - using neil blevins soulburn scripts to replace pflow with proxies

 

and then painting in the flowers, clover, tall grass, trees, etc. with Peter Watje's (i think...) scatter utility.

 

This is a single pass... no z or beauty, etc... just a quick test. I am doing another one tonight that is larger to show you the actuall grass geometry that has a z depth pass (to try and add some atmosphere) and specular ( just for fun).

 

Just used mental ray sun and sky... nothing special except making sure the shadows where soft and upping the shadow samples a little. and turned of aerial perspective (which I think is junk anyways and never use.)

 

I always, always do colour adjustments, etc in photoshop... all the guys who post really nice looking images right out of their render engines drive me nuts because I have no idea how they do it... I still have alot to learn as far as being able to do that.

 

I am of the firm opinion that 99% of my work looks like junk unless I give it some sort of post process treatment... whether it is 2 mins to just play with curves or re-working the entire image.

 

All the textures are from:

 

http://www.cgtextures.com

 

I have a library I have compiled from that site that I rely on pretty heavily.

 

I know the list doesn't end there, even I have alot of questions about the technical aspects of how the material I made works and why... I still play with different maps and combos alot to see what works best.

 

Like with the photoshop rendering walkthrough I did and posted to Vimeo, if enough people are interested I am more than happy to do a quick little scene from scratch, have a beer and ramble on about it while recording myself.

[Justin Hunt]

Have you checked out Jeff Pattons tutorial on translucency. He has ported Peter Guthries vray methode over to mentalray. works really well for trees, I am still to try it for grass but it should work

 

jhv

[Dave Buckley]

i'm interested in a nice little video

 

also very interested as to the material you've settled on for the grass/leaves

 

i've tried jeff's and it is nice, but i find it a little inconsistent with different leaves and doesn't quite look amazing in all situations. but it's definately the best i've seen so far (althought we've not seen yours yet jinsley )

 

first time i've looked at these images on my pc too and my screen must be pretty poor because they looked better on my iphone last night - don't get me wrong they are still good, they just looked exceptional on the iphone

[jinsley]

i'm interested in a nice little video

 

also very interested as to the material you've settled on for the grass/leaves

 

i've tried jeff's and it is nice, but i find it a little inconsistent with different leaves and doesn't quite look amazing in all situations. but it's definately the best i've seen so far (althought we've not seen yours yet jinsley )

 

first time i've looked at these images on my pc too and my screen must be pretty poor because they looked better on my iphone last night - don't get me wrong they are still good, they just looked exceptional on the iphone

 

haha... maybe I need to make a disclaimer that all images must be viewed with whatever screen makes them look exceptional...

 

here is another update with a close up of the proxy geometry.

 

[ATTACH=CONFIG]37518[/ATTACH][ATTACH=CONFIG]37519[/ATTACH]

 

I looked at Jeff's site last night after I saw Justin's post and I wonder how much light leaves really transmit through them... or if they just pick up that sort of glow when viewed with the light source behind them. maybe he just needs to adjust the transparency map... my material really isn't anything special at all I feel.

 

I will have to try and find time to put together another scene using Jeff's set-up, in my experience, Jeff is very good at what he does and it might just take a little tweaking to get the material looking the way you want. even with the material settings I am using, I try and vary it by small amounts so that all the vegetation doesn't have the same physical properties.

 

I had a friend come up from Seattle last night to BBQ and got harassed a little when I wouldn't give him my max scene with the grass geometry so I promised to post a few quick vids on vimeo on how I am currently doing my grass:

 

geometry creation

 

material

 

placement

 

Don't know when I will get around to it, but I will try to do at least one or two this weekend.

[jinsley]

one more done over the weekend...

 

[ATTACH=CONFIG]37571[/ATTACH]

 

I started recording a quick little walk through last night for geometry and materials but Camstudio crashed at the end of it so...

 

will try once more tonight.

[Dave Buckley]

jinsley, i'm happy modeling the grass etc, but something i not sure of is quantities, how big were you proxied patches? 1m diameter circles? 1mx1m squares? also how many blades per patch? and how many scattered proxies on how big an area? i've got 4 proxied patches (long, short, random, patchy) and i'm trying to scatter 25,000 of them over selected polygons on an area of about 50mx50m, it's taking ages to scatter them (i mean like all day) and i have no idea if i'm placing way to many or too little or if it should be taking that long just to scatter them

[jinsley]

jinsley, i'm happy modeling the grass etc, but something i not sure of is quantities, how big were you proxied patches? 1m diameter circles? 1mx1m squares? also how many blades per patch? and how many scattered proxies on how big an area? i've got 4 proxied patches (long, short, random, patchy) and i'm trying to scatter 25,000 of them over selected polygons on an area of about 50mx50m, it's taking ages to scatter them (i mean like all day) and i have no idea if i'm placing way to many or too little or if it should be taking that long just to scatter them

 

aahhh... much easier than what I was planning. I don't have much time this morning because of a deadline but I will write out the basic steps for you.

 

9 inch radius disc for short grass proxies (1.5 - 2.5 inches tall), 6 inch radius for medium and irregular proxies (3 - 5 inches tall), and 3 for tall grass which can be what ever size necessary.

 

On advice from Pixela I use pflow and a cylinder (which represents your grass proxy size) and optimize the pflow to cover the ground evenly... I usaully set the objects to have ~9 in of separation so they don't run into each other too much.

 

I bake the pflow, use object replacer (from Neil Blevins) to replace all the pflow meshes with your short grass proxies... this gives you a very nice starting point with evenly placed grass proxies.

 

I scatter a few of the medium proxies (500 - 1000 depending on size of lawn) and paint in the longer grass proxies to create some irregularity and cover some of the empty patches. Long grass should be placed in places that make sense, like around tree trunks, under bushes, along building walls.

 

I've also found great value in modeling up a few flowers and patches of clover, other plants... its like entourage for you lawn.

 

Hope this helps. I can post an example of the pflow system later if needed...

[Dave Buckley]

thats great, i've used the pflow one before for small bits of debris it was more the size of the proxy patches.

 

but yeh that clears things up for me.

 

do you decide on cam placement before placing grass to help with level of detail and only making the denser bits closer to the camera?

[jinsley]

Having an idea of the shot needed is great and can save you tons of time, but with most of the projects I do at work, I end up setting up the grass last and usually for around 4 views.

 

i'm pretty fast at it now! I have my set-up time down to around 30 mins and most of that is processing.

 

I will post my material set-up tonight Dave, I saw Jeff's over at his blog and I don't really know if I agree with it visually... I don't think that the entire tree should be lighting up the way that his does... I tried to post some questions to him, but I don't seem to be able to post to his blog...

[Dave Buckley]

cool that will be awesome, is your leaf material the same as your grass?

 

did you see jeff's grass material over on mrmaterials.com

[jinsley]

Yes, the leaf material is the same as the grass... when I went out and took photos, it seemed that both grass and leaves have very similar properties, but in the leaves you get a lot more structure showing through (veins, etc...) when they are back lit.

 

I saw Jeff's post ( I assume it is the one that uses the translucency (lume) shader) at his blog... I don't know if I agree with it. When I look at photos and go outside, not a lot of light penetrates through leaves... they just get back lit and display sss. Definitely no colour transfer occurs to the naked eye. i don't think that the leaves should be lit right to the core of the tree, in my observations the darkness at the trunk has a direct relation to the density of the foliage... not light transferring through the leaves...

[Dave Buckley]

oh no, it's not the one at his blog, it's one he's uploaded to mrmaterials.com, its here http://www.mrmaterials.com/resource-central.html?func=fileinfo&id=987

[jinsley]

I do remember looking at that one a long time ago... I can't remember my login though or even if I have one...

 

it looks nice though! Do you have any examples of it rendered? hmm... I will have to re-register later or try and get my pass emailed to me...

[Dave Buckley]

i'm going to run a few renders tomorrow and will post results using that material, but from what i remember, the result that i've just posted was tested with a daylight system rather than the photographics studio setups that you often see with those material tests

[jinsley]

looking forward to seeing it... will be interesting to see how the material is built up... I wonder if it is similar to:

 

http://3dsmaxrendering.blogspot.com/2008/06/translucent-leaves.html

[Justin Hunt]

He does push it a little too far, and admits it too

[jinsley]

He does push it a little too far, and admits it too

 

Well I don't know if its too far... I think it looks quite nice graphically, in the right render it would look great...I'm sure you would be able to clamp off the colour transfer if you wanted.

[Justin Hunt]

Often I have a problem with foliage getting too dark, too much shadow. A toned down version of Jeff's tutorial worked out very well. I was always worried that translucency would add a heap of time to the render but it's not too noticable.

[jinsley]

Often I have a problem with foliage getting too dark, too much shadow. A toned down version of Jeff's tutorial worked out very well. I was always worried that translucency would add a heap of time to the render but it's not too noticable.

 

same here... but if you look at trees lit under different conditions... they do get dark areas no matter what. s

ame tree shot from 3 different angles:

front lit

[ATTACH=CONFIG]37593[/ATTACH]

back lit

[ATTACH=CONFIG]37592[/ATTACH]

side lit

[ATTACH=CONFIG]37594[/ATTACH]

[Dave Buckley]

another quick question, when spreading grass using pflow, how do you stop the cylinders from overlapping too much? can you enable collisions somewhere

[Dave Buckley]

do you optimize your proxies in anyway?

 

i've just scatted 3500, .5m radius proxies, each containing 2500 blades, so essentially 8million+ blades of grass.

 

safe to say it fell over with insufficient memory issue, i have 8GB of RAM and am working on Windows 7 64

[jinsley]

do you optimize your proxies in anyway?

 

i've just scatted 3500, .5m radius proxies, each containing 2500 blades, so essentially 8million+ blades of grass.

 

safe to say it fell over with insufficient memory issue, i have 8GB of RAM and am working on Windows 7 64

 

to keep them from overlapping too much you can set a separation distance in your pflow on the position object operator...

 

that doesn't sound right... my grass blades are 4 polys for short and medium length grass, and 5 or 6 for long grass... for short and medium grass I distribute 1000 blades per proxy object...

 

the scene that I have been posting uses ~20,000 grass proxies (approx. 3000 - 4000 polys each.) and around 100 tree proxies (range from 300,000 to 500,000 each...) and then the clover and flowers too. are you using bsp2? I could be wrong, but I don't remember my ram exceeding 6500mb... I think you should be able to distribute far more proxies than your current limit...

 

if you look back to the image I posted on Nov. 16 in this thread, that image had 60,000 grass proxies alone. Max was very unstable but it rendered on 8 gb of ram at 2250 px wide... how large are your renders Dave?

[Dave Buckley]

640x480 while testing, i even tried reducing to 400x300

 

bsp2 enabled, scanline disabled, everything on draft.

 

i've got a 4MB zip file i can send you containing the test scene file and the associated proxies and the original proxy scene files (will need grass-o-matic) to view these

 

it's max design 2011 though so if you need it back saving to 2010 i cna do, just need a method to get it over to you

 

you can email me at dave@davebuckley.co.uk if you wish and that way i'll get your email and can upload it to dropbox or something

[jinsley]

I can give it a go later today if you like... I sent you an email, I think you can send the zip right to me...

 

right off though, I think that grass o matic is the problem... when I started this thread a year or so ago I was using it alot and I found that it was causing lots of problems when the patches I was creating were converted to proxies...