Yes, you can upload a SketchUp (.skp) model to the 3D Warehouse for a specific recipient, but 3D Warehouse is primarily designed for public sharing. The best way to share with a specific person without making it public is to upload it as a Private Model.
Here are the best methods to achieve this:
3D Warehouse "Private Model" Method
While 3D Warehouse doesn't have a direct "share with user X" button for private items, you can use the private setting for security:
Upload & Set to Private: When uploading, under "Additional Attributes," select Private Model.
Limitation: Only you can view private models; you cannot directly share the link with specific people to download.
Workaround: You may have to temporarily set it to "Public" to send a link, or use the Trimble Connect method below.
The Best Way: Trimble Connect (Recommended)
For secure, private sharing with specific individuals, use Trimble Connect, which is built into SketchUp (2024 and earlier).
Save to Cloud: Save your file to Trimble Connect (using the cloud symbol in SketchUp).
Share Link: Generate a view-only link to the project.
Permissions: You can control the level of access to those you've shared it with.
Alternative: Private Collections
Folders: You can create "Private Folders" to curate models that only you can see.
Collection vs. Folder: Remember that "Collections" are public, while "Folders" are private.
Summary of Sharing
Public Link: If you upload publicly, anyone can download it.
Private/Shared: Use Trimble Connect for secure, named recipient sharing.
Key Takeaway: If the goal is truly private sharing with a specific recipient, use Trimble Connect. If you just want to hide it from general search, use the "Private" upload setting in 3D Warehouse, but note it is difficult for others to access.