Pirros automatically renders a 3D thumbnail for every loadable family when it's uploaded. When that auto-generated preview doesn't represent the family well — common for system families like walls, floors, and curtain walls, which Revit renders poorly — you can replace it with your own image.
Note: This is different from the firm-wide Thumbnail Previews settings that control how Pirros auto-generates 3D thumbnails at upload (visual style, detail level, view angle). Those are covered in Uploading RFA Files. This article is about overriding the preview for one family with an image you supply.
How to Replace a Thumbnail
First, open the thumbnail manager:
Navigate to the Families page and open the family you want to update
Click the three-dot menu (⋯) in the top-right corner of the family's page
Select Manage Thumbnail
The Manage Thumbnail window opens. The left panel lists every type in the family; the right panel is where you upload an image for the type you've selected.
Then upload your image:
Select a family type from the list on the left (a family with a single type will have just one entry)
In the upload area, drag and drop a .jpg or .png file, or click Browse Files to pick one from your computer
Repeat for any other types you want to give a custom thumbnail
Click Save and confirm the update to finish
File requirements: JPG (.jpg / .jpeg) or PNG (.png), up to 10 MB. There's no required size or aspect ratio, but a roughly square image looks best in the Families grid. Uploading an unsupported file shows "Please upload a .jpg or .png file."
Apply One Image to Every Type
If you'd rather every type in the family share the same thumbnail than give each its own, upload an image for one type and click Set as Default. Confirm when prompted — "All family types will share this thumbnail. You can remove it later." — and every type adopts that image.
Remove a Custom Thumbnail
To revert a type back to its auto-generated 3D preview, open Manage Thumbnail, select the type with the custom image, and click Delete Thumbnail. Confirm when prompted. The custom image is removed and Pirros' rendered thumbnail returns. This only affects the preview — it never changes the family file itself.
What Happens Next
The new thumbnail appears immediately on the Families page and anywhere the family is shown. Custom thumbnails are preserved across future updates — when the family file is re-uploaded or versioned, Pirros keeps your custom image instead of overwriting it with a fresh render.
Frequently Asked Questions
Q: What file types and sizes can I upload?
A: JPG (.jpg / .jpeg) or PNG (.png), up to 10 MB each.
Q: My system family (wall, floor, curtain wall) has a blank or messy thumbnail. Is something wrong?
A: No — system families often generate poor default 3D thumbnails due to Revit limitations. Upload a custom image to replace the preview. This won't affect the family file, only how it looks in Pirros.
Q: Can I set different thumbnails for different types in the same family?
A: Yes. Select each type in the left panel and upload an image for it individually. If you want them all to look the same instead, upload one image and click Set as Default.
Q: Will my custom thumbnail be wiped when the family is updated?
A: No. Custom thumbnails are preserved across updates and new versions — Pirros won't overwrite them when the family file changes.
Q: Can I replace the preview image for a detail or project too?
A: This workflow is for families. Detail and project previews are generated automatically and can't currently be replaced with an uploaded image.