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jerryshuchen
10-31-2012, 03:43 PM
Hi,

I want to make a very large range of grassland with trees. It's a still image, camera position can't move, and need to export the picture of 12000 pixel. I am using vray.

I have tried,
1. vrmesh of 1*1 grass field, but it is too heavy for my machine to fill the land.
2. Hair, I cut the land by 20 pieces to add it, my scene needs almost 350000 for each piece, and it's still too heavy.
3. vrayFur, the result isn't satisfy, it looks like an oil painting.
4. displacement mat, also looks not well.

The picture is in the attachment.
Dose anyone has a good idea to help me? thanks a lot !

typografschaft
10-31-2012, 03:50 PM
Try rendering the Grass with Fur or Hair Object with Physical or Advanced Renderer.
Also try rendering in patches and combine them afterwards.
12K will be heavy on every machine, no matter how powerful it is.

xdennisx
10-31-2012, 05:31 PM
Render one patch and use it as a texture + bump/normal? From this distance you should not see much difference.

lllab
10-31-2012, 07:28 PM
use proxy2 and come into vray forum for help :-)

25000 hair patches (real 3d grass as proxy2, at least each about 100-250 grass pieces, so about 2million blades) rendertime 2min with gi, real reflections on grass, physky, thin sss and all, renderimg itself takes only 3.2 gb ram.

and many times more copies are easy possible:

http://images-stefan.s3.amazonaws.com/3d%20proxy%20scatter%20grass-dof-mograph.jpg


cheers
stefan

vrayforc4d.com

lllab
10-31-2012, 07:40 PM
p.s. just tested 80000 proxies of the grass patch , thats about 80000000 grass piexes, which cancover a huge area if scattered well, take 5,2gb ram, and render the same scene in 3min29sec. so almost no difference despite the huge increased in proxy amount. the very far away parts you can still do with texture and or displacement

lewisrowe
10-31-2012, 11:17 PM
Hi Jerryshuchen,
I had to do a similar job recently in a hurry. It was a massive high res strip of grass for a very long murial at an airport. I had problems with at first with memory as I wasn't doing it in the best way, but I rendered ten 8000px sections over night (pretty fast I think) to join together and the results were fine. I adapted a Vray fur grass scene downloaded from the forum.

Stefan can help you with a good efficient setup for this. But if it helps you're welcome to have my scene file. just let me know.

jerryshuchen
11-01-2012, 03:35 AM
Try rendering the Grass with Fur or Hair Object with Physical or Advanced Renderer.
Also try rendering in patches and combine them afterwards.
12K will be heavy on every machine, no matter how powerful it is.

Thanks. I want to use vray and there is not only grass and tree in the scene, it combines other things, so I think vray can present more natural.
And if rendering in patches, it is a way, but it needs to render 12 patches for each preview.
And there is some interactions between objects, it will make a lot of trouble to adjust.

jerryshuchen
11-01-2012, 03:39 AM
Render one patch and use it as a texture + bump/normal? From this distance you should not see much difference.

Thanks.
I think this way is not suitable for me, I have tried texture with displacement, but the result is not well. I want to remain true.

jerryshuchen
11-01-2012, 04:43 AM
use proxy2 and come into vray forum for help :-)

25000 hair patches (real 3d grass as proxy2, at least each about 100-250 grass pieces, so about 2million blades) rendertime 2min with gi, real reflections on grass, physky, thin sss and all, renderimg itself takes only 3.2 gb ram.

and many times more copies are easy possible:

http://images-stefan.s3.amazonaws.com/3d%20proxy%20scatter%20grass-dof-mograph.jpg


cheers
stefan

vrayforc4d.com

Thanks.
What is proxy2? Is it in new vray1.5?
Do you mean 25000 hair patches made by C4D Hair or by polygons?
For c4d hair, the length is 1 cm because of the proportion, then it needs 350000 for one piece.
And my land is undulating terrain, a big proxy can not fit with the terrain.

jerryshuchen
11-01-2012, 05:02 AM
Hi Jerryshuchen,
I had to do a similar job recently in a hurry. It was a massive high res strip of grass for a very long murial at an airport. I had problems with at first with memory as I wasn't doing it in the best way, but I rendered ten 8000px sections over night (pretty fast I think) to join together and the results were fine. I adapted a Vray fur grass scene downloaded from the forum.

Stefan can help you with a good efficient setup for this. But if it helps you're welcome to have my scene file. just let me know.

Thanks.
If it is possible, can I download your scene file?
And how did you test the result, I mean after u adjusted grass mat, how did you preview it?

scense download link :
http://cnc.good.gd/?FileId=2278440&on=q.zip&cn=ed3a6ec9-0923-4ed6-9d83-45efbf91b64f&ut=2012-11-1+13%3a12%3a00

lewisrowe
11-01-2012, 01:13 PM
Here you go....
http://www.lewisrowe.co.uk/things/Vray_Grass_10xTiles.zip
(R14 doc)

I previewed the whole scene in the viewport with my preview render settings(included) to judge the colors, then previewed a small full-res section using Vray's region render settings.

Thanks and credit goes to 3DKobi for the original material. Found here: http://www.vrayforc4d.net/portal/category/material-keywords/grass?destination=taxonomy%2Fterm%2F184

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