I usually make the bottom of the lake as part of the topography, add a muddy subregion to the bottom, and "fill" the lake with an in-place mass (or generic model), with a liquid material applied to it.

I"cover" the lake with another topo surface, set to water.

But it's been a while.

Topo surface for the bottom of the lake with a subregion set to a material like sand or if your creative make an awesome bottom of lake material. Then a floor for the water surface. See attached for a couple examples. this has a different material in the bottom of the dolphin tank vs the bottom of the sea beyond.

Excellent - many thanks.

May I also ask a simple Q: I'm coming to Revit from other programs (Vectorworks, Microstation, etc) where this is straight-forward: it's v hard to understand how to just export out a final image in its fully rendered hi-res form.....!

- 'Revit' button > Export > Images & Animations > Image...does not render the image if you're in the 3D view, and appears to export a poor res image if you're in the Renderings part of the Project Browser (it seems only low-res images are stored there)

???

You'll get the best results by exporting straight from the Rendering dialog (The Teapot).
And to render in the quality and resolution you wish, just tweak these settings:

- Quality > Setting = Low-Best (Try "High" for a starter)
- Resolution > Printer = Choose DPI (Choice will depend on the physical size of the camera view)

- Physical Size > In the camera view, pick the border of the view, and use "Size Crop" to adjust to the final output.

- For most printing jobs, 300 DPI is fine, so to print a A4 page, set the physical size of the camera to 297*210 mm, and the DPI to 300. This will result in a image at 3508*2480 pixels. Also notice, that each time you double the DPI the total amount of pixels are qua-doubled, meaning that it takes ~4 times longer to render.

- When done with the settings, hit render.
- Wait
- Export to the format of your choice. (I like PNG or TIFF, but note that you'll need JPG or similar if you want the sky to be kept in the exported image)

...as in quadrupled?

Have NO idea... Something fourish

Thanks Klaus..would have been stuck without your post. Am nearly there, but:

Rendered on 'High' the jpg comes out at only 529K..too small for presentation (although I note a png export is 11.7M). I need the sky. I've attached the settings in Revit used, and the jpg opened in Photoshop, which strangely shows the resolution as 96 pixels/inch whereas my Revit setting was clearly 300 dpi..

Bitmap exports as 34MB, but shows identical settings as the jpg when opened in Photoshop (ie. 96 pixels/inch)