Forests in maya mental ray.

#381

Joie what Tostao just pointed out, is that if you group the polymesh box, which holds the mip_binary_proxy node, under a new empty group, and you instance the new empty group,
all the new instances, will inherit the same polymesh box with the mip_binary_proxy node, connected to its Geometry Shader field.
The workflow of grouping maya nodes, under an empty group, is often used to animate maya nodes, which already has some sort of deformer applied, or some of the attributes already keyframed.
I just rendered out 11 copies of a few millions poly Ivy object in Maya 2009 sp1a, with very elaborate mia materials and misss_fast_skin networks, applied to the leaves and branches, using this workflow, and everything is ok…!
Using the scanline and the standard Bsp algorithm…!

For more Info’s, check this links:

http://forums.cgsociety.org/showthread.php?f=87&t=747229&page=1&pp=15&highlight=binary+proxy+instance

http://forums.cgsociety.org/showthread.php?f=87&t=607924&page=1&pp=15&highlight=binary

http://forums.cgsociety.org/showthread.php?f=87&t=802195&highlight=proxy+instance

Hope it helps…!:wavey:

Alex

#382

Well, in SP1a rendering with BSP2 and raytracing it won’t render ten trees with the same mip_binaryProxy node…

Tostao, I think I tested it in 2010 but I can’t remember it well right now, I unistalled it since the mr passes issues hadn’t been fixed so I’m sticked to 2009.

#383

The issue you’re describing is fixed in 2010.

#384

The ten mip_binaryProxy limit or the mr render passes one? :stuck_out_tongue:

Okay, I guess the fixed one is the proxy related one :wink:

Right now I can’t verify that, but I’ll try when I have time.

#385

The ten mip_binaryProxy limit.

#386

This is a grass test that i’ve made. It’s an animation and i’m only posting some frames.

It took 1 min by frame with fg map in freeze.
1 grass patch duplicated (instance)

#387

more images

#388

Hi Syna;

Could you show how your grass patch looks like?, Is it round or square?, Is it dense?.

Thank’s.

#389

it’s a rectangle with 26600 polys. All together is 16022832 polys

#390

Thanx guys, I’m glad that you like my humble efforts :wink:
My workflow is pretty much based on Peter Guthries exellent technique explained here:
http://www.peterguthrie.net/blog/2009/03/vray-grass-tutorial-part-1/

I modeled 3-5 unique blades, then used the exellent painter-script to randomly paint an
area of about a square-meter (made some different tests here with both square and round patches, also with smaller patches like 25-35 cm). Then I combined all the blades of one patch and used that one with the painter-script to start painting a larger area. All instances, no proxies used.

@syna: That is lookin good! :wink:

Cheers

//NIC

#391

Hey guys about the grass. I had the issue where I need the grass to be densely packed in the areas needed but not going off the geometry that required the grass. Kinda how a road would suddenly kill grass.

This kinda killed the idea of using circle patches of grass and then just using instancing it across particles as the circles would cause half the radius to get on the road.

So instead…I used small grps of grass. like 5 blades instead packed closely…but I ended up using the particle tool and painting all night long. Is there a better way to distribute particles across a surface densely and quickly?

#392

I don’t think you really need the particle distribution method. I know it has benefits, but if you’re painting particles then you might as well just be painting instances. You have more control over them, and can easily tweak any 5-blade instance in particular for size or rotation. I’ve had decent luck with this method, but still my grass doesn’t look as good as others who have posted here. My grass material isn’t quite up to snuff, but the placement is much simpler.

The best tool I’ve found for painting instances, basically replacing any need for Vue’s ecosystems for me, is spPaint3D. It’s a raycast instance painter, meaning it’s not UV-map dependant. It’s saved the day many time for me, and I use it almost daily now on my personal projects. Mentioned it before, and it looks like this:

#393

That’s the script I was reffering to (when I wrote “painter-script”, actually InfernalDarkness, I’m pretty sure that it was from you that I picked it up in the first place and I have to thank you for that, now I don’t see how I’ve managed without it in the past).

@Kinematics: Just use the script to paint round or square patches to fill the larger areas of you terrain, then in the areas where you want to have more control of your composition use the same script but use single blades (3 or more) or clumps of grass to fill in the “blanks”. Eg the side of the road in this case.

#394

Ah I see, I wish i had asked earlier now that i’ve painted the whole field. I am gonna try it this way. But guys, would u say the purpose of using instance in this case is because the poly count is low and if it is ever in regards to trees with high poly counts only then is binary proxy useful?

Okay yes this would have been a really useful script now that ive tried it out but still I find myself painting like crazy to cover a huge landscape. Is there away to evenly spread particles across the field? Like pretty densely packed ones? cause painting is a lil time consuming. With large circular grass patches…alot of polygons are wasted overlapping each other to cover up the gaps.

Any way to do this? cause the shot is from a high up angle…i realized from low angle shots…these methods work really effectively but say an entire forest covered in grass? top view?

#395

Thank you for all the great tips!

I have attached a few renders of a grassy patch I made. Feed back would be awesome!
This is almost 8 million polys. The first image is rendered in 18min and the second in 9 minutes.

On the right side of both images you can see the 6 original strips of grass. The materials are 2 mia_material_x. On the second image you can see the round patch that was painted onto the hillside using spPaint3d, using the instance option. Navigating in bounding box mode really helps.
I am not using the mia exposure photographic… would that help my scene?

Quality setting wise I’m using toi gamma framebuffer adjustment on the “sun and sky”. Rendering is… raytrace, maxsample of 1, filter= box,FG accuracy =100,point density =1. No global illumination.
Im using raytraced shadows with only one original sun light with default settings. I originally tried painting fur with the grass preset and also tried assorted pfx grasses but could not get very good results. I do have those results with the same render settings if anyone wants them, the render times are longer too. My grass is also NOT a double sided texture, would that help? I will use that on my leaves. so… help me make my grass look better! Oh pretty please?!

Again, thank you for this thread. I will try placing some trees once my grass is down.

Rasa

#396

that looks nice syna. When I did that test ,I ran into flickering problems in the areas towards the horizon.
are you getting those problems. If no than can I see your file. that Flickering is the only thing which is bothering me and I would really like to know how to work around that.
thanx

#397

I must say that I very much like your shading of the grass, is that translucency only or did you spice it upp with som real sss?

#398

Now I’ve tried the particle-instancer approach as well, I’m very found of the way I now can plant loads and load of grassblades for making that short cut lawn-grass or similar. But what really bugs me is that I haven’t found a way to convert the instancer to poly? So I don’t really see the point of using this approach?

#399

So here is another sample, but next time I promise I will use Mip_binaryproxy and mia exposure photographic. With 30 million triangles maya gets really slow. I have lots of ram etc. I hope spPaint3d can handle painting Mip binaryproxy. Im really looking forward to this! Oh yes, and I will put in a tree with leaves facing the sky, double sided textures etc. Thanks again.
Rasa
ps I didn’t use SSS on the last images, just Mia material x, with one shader.

edit: ok even though spPaint is on instance. I be thinking those are copies. Can instances not be obvious in the hypergraph? They don’t look like instances… Of course the scene file is only 15mb, so they must be?

Rendertime: 20min/30,000,000 triangles 720p

#400

I don’t think i have that much flickering, but see for yourself.
I’ve uploaded some frames so you can see the animation. http://www.megaupload.com/?d=G47UWYJI

The purpose of this grass was to look good and render fast in animation i was not so interested in a still.