Paul has the right idea…just saw that you posted! 
It depends what you want your proxies to be. A cube, or a lower poly representation, or 2d symbol for use in Plan views (like i do). Each renderer has a slightly different approach and function to working with source material (offline proxies and such).
Show us some visuals of what you’re working on…might give a better idea of how we can assist.
Saving SketchUp components OUT of a model as a collection is easy enough; just view all components “In Model” then use that right arrow menu icon to “Save As Collection” and it’ll create a folder full of all the components. You can place copie sof a SKP fle which i sjust a cube i nto that folder and then rename those cubes, so if you have Tree1.skp in your model, you rename the cube Tree1_proxy.skp. There used to be some windows scripts to automate that renaming process…can’t think where though, was a long time ago.
Getting these proxies back into sketchup requires a few clicks per component…and there are several methods available. I dont know of much faster methods to get them back in… Reference Manager would surely help.
- using the Replace Selected function (open your new collection full of proxies in the comp browser. select the components in sketchup that you wish to replace. right click in the comp browser and choose Replace Selected).
- select the component in the Comp browser and right-click “reload” then select the proxy from your windows folder.
- Install the Component Replacer extension and use that to swap out components. I find this very handy.
In my workflow I avoid this issue with landscaping because i use components that have both a high and low poly version, each on a seperate tag. If I want to make the model simple I can delete that HQ tag altogether, eg if sending to LayOut.
For almost all components in my library, they are modelled with quite a high poly count and realism - suitable for rendering. But each of them also has a 2d symbol version - it’s both a Proxy and it’s a 2d CAD-stye symbol that is represented on site plans/elevations. So think of it that way… you have a 2d symbol for everything and can design in “plan view” using symbols, or you can click a button and your 2d plan becomes a raytraced render.
You can do lots of things like that… I do site plans where the Proxy is the ground floor plan, and the HQ version is a building with 1m+ polygons.
In the rock wall example I would build a section of rock wall and place copies of it manually to create a larger wall assembly. (see the hedge in the image below …three copies of the same hedge, flipped and rotated for variety). Then I’d just copy in the Low quality geometry (like that flax plant in my image) and delete out the HQ version.
The hedge component shows a similar approach…it’s basic copy is the exact size of the original HQ component so I can place them around my scene with some accuracy, knowing htey;l swap to a HQ version upon rendering. The texture is large enough that i can see whether it has been flipped. The size of the hedge is small enough that i cna stretch/squash it to fit around curves etc without overly distorting it. And the Hedge texture could be a pattern or something you would look suitable for a 2d site plan.
It’s pretty Low-quality, but you can adjust that. Its important to have 3d objects to design with, otherwis eyoure just doing 2d cad with 3d proxies…better to design in 3d.
On scattering Generally//
Scattering is a function of my renderer, and it works exactly like Skatter. But yes you can’t see the objects or manipulate them in SketchUp. Only after they’re rendered.
Extensions “Fur” and “CompoSpray” are two examples. Both place scattered components on a plane, similar to Skatter, but they can then be shifted manually.
There are extensions that can do arrays, or copy along path, or similar for more Linear thngs like hedges or trees lining a street.
There’s also one by Eneroth which ranomises components upon placing them, so trees get a slightly unique scale, rotation, skew, etc… Sometimes you need 2 or 3 trees of a certain species to give enough variety to the scene if you have lots of them.
For rocks, bushes, etc, I tend to copy and paste large bunches of components, rotating each bunch and scaling it slightly as I go, then I explode the bunches (back to individual plant components) and delete any of them that have landed outside of my boundary area.
