Take a picture
Crop picture. In this case, I chose a 1 x 1 ratio. (I like to use FastStone Image Viewer.)
Save in a folder
In this example we will start with “Dirt – Dark Brown” OOTB (non-advanced asset Revit 2019, regular asset Revit 2008-2018).
Duplicate the material and rename, duplicate the asset and rename
Replace the material with the new photo
Figure out a sample size
The bump map can simply be the same photo and sample size (to start with)
Make Seamless Image
Go to https://www.imgonline.com.ua/eng/make-seamless-texture.php . There are other ways to do this, but that site makes it very easy.
Upload your photo
The site has several options. They can all be tried to get the desired effect.
This explains it somewhat:
Go with No. 4-A for this
Can check the result
Save to “Site-Gravel-Seamless.jpg” in folder in Revit’s rendering path
Change the image paths in Revit
How about double the image? Send the new image back up and apply the same processing to it.
Make a bump image from the original image. Turn down the saturation, up the contrast, change gamma…
Apply to appearance at the same size as the other image…
Super Fractal Bump Trick
There are myriad bump settings for applying fractal noise combined with images combined with fractal noise. These are the settings I messed with until I liked the rendered result:
These rotation parameters can be adjusted and previewed, but the values do not seem to stick in the dialog after it’s closed:
Hence we can overcome the tiling effect with the recursive bumps.