Noise

[glorybound]

I do a lot of exterior illustrations, as you might know, and I have a question. I like to roughen up my site with a noise, but I want it to stay away from the edge. For an example; if I have a driveway running through grass I want the noise on the grass, but not effect the edge that touches the driveway. Is there a way to do this?

[cheerioboy]

Select verts or polys of the geometry you want the noise applied to before applying the noise?
You can also use a vol. select modifier with a texture that will then select the verts based on a black and white texture

something like that?

[Shimakaze]

Normal noise or VrayDisplacement? If normal noise, then it's very easy to use volume select modifiers to subtract parts of a mesh from the selection before applying noise. If VrayDisplacement, then you can use one of several methods to mask out the parts you don't want. You can use vertex colors with a mix map to control the strength of the displacement, or you can use a UV based method with a masking image, or you can use VrayDistanceTex with an object that fills the driveway, or you could probably use ColorEdge from here http://www.itoosoft.com/freeplugins.php

[glorybound]

volume select modifiers - I'll have to look into that, thanks!

Normal noise or VrayDisplacement? If normal noise, then it's very easy to use volume select modifiers to subtract parts of a mesh from the selection before applying noise. If VrayDisplacement, then you can use one of several methods to mask out the parts you don't want. You can use vertex colors with a mix map to control the strength of the displacement, or you can use a UV based method with a masking image, or you can use VrayDistanceTex with an object that fills the driveway, or you could probably use ColorEdge from here http://www.itoosoft.com/freeplugins.php

[dlparisi]

I've done this before with a volume select modifier on the grass and using the driveway as the mesh object in the volume select (you may have to "push" or tweak the extents of the driveway a bit though). Ideally use the curb if you have one. FOr the vol. select set it to vertices, invert and use a soft selection as necessary. After you have all of the verts properly selected apply you noise modifier like normal.

[glorybound]

I have tried the first, which is the most obvious, but it doesn't seem to work that way.

Select verts or polys of the geometry you want the noise applied to before applying the noise?
You can also use a vol. select modifier with a texture that will then select the verts based on a black and white texture

something like that?

[Shimakaze]

I have tried the first, which is the most obvious, but it doesn't seem to work that way.

It should work with just selection verts directly, as long as you make sure the selection is maintained up the chain of modifiers.

[Pixelcon]

Or do a noise modifier, soft select the border verts, align z and drag back down to the level you want. Smooth edges. Bam.

[glorybound]

this is working, but painfully slow. I have a pretty dense mesh

I've done this before with a volume select modifier on the grass and using the driveway as the mesh object in the volume select (you may have to "push" or tweak the extents of the driveway a bit though). Ideally use the curb if you have one. FOr the vol. select set it to vertices, invert and use a soft selection as necessary. After you have all of the verts properly selected apply you noise modifier like normal.

[Shimakaze]

this is working, but painfully slow. I have a pretty dense mesh

One way around it, if you are using volume select, is to use a low poly mesh as a base, and use a turbosmooth modifier to get the needed density. That way you can keep the subdivs at 0 for viewing and up the render subdivs to whatever you need. The alternative is to use the VrayDisplacement system instead so you can avoid having to deal with sub-object selections completely.

[glorybound]

It took a few minutes to churn, but it worked great!

[piotrus3333]

I use poly/mesh select in those situations (noise mod on grass plane):
grass object >> poly select - select border (if you dont need border selection just use mesh select) - click vertex selection with cltl - invert selections (that gives youy all but the border vertices) - shrink a bit if needed, soft selection >> apply noise modifier