Large scale terrain rendering with cleaner grass surface

[pietervanstee]

Hi,

I'm working on a project of a larger scale.
There is a central existing building that will be remodelled, and around it a golf course will be constructed.
The attached image is a very low quality draft render but I'm also getting this problem on the zones where there is shorter grass with higher quality render settings.
Does this have to do with the GI settings?
If there's anyone that can share some tips for this render setup, it would be much appreciated!



edit: increasing the render settings in general did help, but I'd still like to know what to increase exactly to tackle this issue efficiently.


Thank you,
Pieter

[Vizioen]

Might be worth sharing your render settings. Also what scatter system do you use and are you sure, it hasn't got anything to do with the distribution of your grass.

edit: apparently it's your render settings; do you use BF+LC or IR+LC?

[pietervanstee]

Hi Ashley,

Thank you for your reply.
Well the grass is one of the common grass in combination with one of the higher grass from the forest presets, so I don't think it has much to do with the geometry...
Was just thinking if I was using this in a large scale environment there might be problems with the surface underneath the grass?
As render setup I'm using IR LC.
I've attached some screenshots of my settings below:





Pieter van Stee

[Vizioen]

You're saying you use IR LC but your settings say BF LC

[pietervanstee]

Yeah, you're right there!
This project had to go very quick to generate some tests that I've overlooked that.
Usually I start with the vray preset dialog and tweak from there on.

Most of the time I'm used to work with IR and LC...
However I believe in some earlier tests with the IR and LC the problem seemed the same.

[Lupaz]

Well the grass is one of the common grass in combination with one of the higher grass from the forest presets

Are you saying that the grass is actual geometry from forest pack pro?
If your shot is from so far away, why are you using geometry for the grass?

[Morbid Angel]

I believe the way the region render works is it actually calculates some gi settings differently then full frame render. That is why you are seeing this artifact.

[pietervanstee]

Hi Guido,

Yes indeed, you've got a point there, but it seemed more logic to use one method for the vegetation for both distant and close up shots.
Otherwise I have to match vegetation/grass with the forest vegetation I'm using for the close-ups.

Or do you recommend another workflow there?
Thanks

[pietervanstee]

It's possible that the render region also causes it's problems, but in the second render with the render region turned on, the artefacts are already much less.

[Vizioen]

Well I never use the quick settings. And I just tried to recreate the problem by using the common forest pack grass on a large piece of (flat) plane. Ofcourse I don't know if you changed some settings in this forest preset but I left it as it is (except camera clipping). I didn't succeed in recreating the blotches, which are quite common to the IM, that's why I always use BF.

So in order to check if it's rendersetting related, I suggest returning to the default settings (switch to scanline and back to vray). Enabling GI. Setting the noise threshold of the bucket image sampler to 0.03 instead of 0.01. Don't touch anything else (maybe dynamic memory limit to 0 with so much geometry) and check what that gives you.

[pietervanstee]

Hi Ashley,

Thank you for the advice, I'll try that soon.
Bedankt!