SketchSpace VR workflow
- Print the SketchSpace VR cube-room template.
- Students draw the six panels: ceiling, left wall, front wall, right wall, back wall, and floor.
- Photograph the completed template.
- Crop the photo to the outside border.
- Upload it into SketchSpace VR.
- Use fullscreen, split view, or VR glasses mode.
- Place the phone sideways into the cardboard viewer.
What you are building: a simple handheld cardboard viewer, similar to Google Cardboard. It needs a phone, a cardboard body, two biconvex lenses, and a simple way to hold the phone in place. It does not need electronics, batteries, a head strap, a magnet button, NFC tags, or Bluetooth controllers.
Cheapest path
Buy lens pairs and make your own cardboard viewers.
This usually gives a classroom the lowest cost per viewer.
Easiest path
Buy prebuilt Google Cardboard V2-style viewers.
This is faster when the build time matters more than the price.
Important purchasing note
Google no longer sells the original official Google Cardboard viewer directly through the Google Store. For classroom use, look for Google Cardboard-compatible lens pairs, Google Cardboard V2-style compatible viewers, DIY Google Cardboard-style kits, or generic cardboard smartphone VR viewers.
Amazon, Walmart, eBay, AliExpress, and electronics suppliers change inventory often, so this guide uses search links instead of relying on one unstable product listing.
Recommended lens search terms
- Google Cardboard lenses 25mm 45mm focal length biconvex
- Google Cardboard V2 lens pair 45mm focal length
- biconvex lens pair for Google Cardboard
- 25mm 45mm focal length biconvex lens VR
- 34mm 45mm focal length biconvex lens VR
Best lens specs
| Lens type | biconvex |
|---|---|
| Focal length | 45 mm |
| Lens diameter | 25 mm to 34 mm |
| Quantity | 1 pair per viewer |
Lens search links
- Amazon lens pair searchGoogle Cardboard lenses 25mm 45mm focal length biconvex
- Amazon V2 lens searchGoogle Cardboard V2 lens pair 45mm focal length
- Amazon bulk lens search25mm 45mm focal length biconvex lens VR
- Amazon 34 mm lens search34mm 45mm focal length biconvex lens Google Cardboard
Prebuilt viewer search links
- AmazonGoogle Cardboard V2 viewer
- AmazonGoogle Cardboard-compatible VR viewer
- Amazoncardboard VR viewer for smartphone
- AmazonDIY Google Cardboard VR kit
- Amazonbulk Google Cardboard VR viewer
- TinkersphereGoogle Cardboard Viewer V2
- CRCiberneticaDIY Google Cardboard V2
- eBayGoogle Cardboard V2 viewer
- WalmartGoogle Cardboard VR viewer
- AliExpressGoogle Cardboard V2
Materials for one DIY viewer
| Material | Amount | Notes |
|---|---|---|
| Corrugated cardboard | 1 sheet | About 12" x 18"; thin shipping-box cardboard works |
| Biconvex lenses | 1 pair | 25 mm or 34 mm diameter, 45 mm focal length |
| Velcro dots or strips | 2-4 pieces | Holds the phone flap closed |
| Large rubber band | 1 | Backup phone holder |
| Binder clips | 2 | Optional side clamps |
| Clear packing tape | small amount | Reinforces folds and lens holes |
| Glue stick or hot glue | small amount | Holds tabs and lenses |
| Scissors or craft knife | 1 | Adult use recommended for craft knives |
| Ruler and pencil | 1 each | Needed for measuring and marking |
Other material searches
Working measurements
| Distance between lens centers | 64 mm |
|---|---|
| Distance from phone screen to lenses | 40-45 mm |
| Lens focal length | 45 mm |
| Viewer width | 150-165 mm |
| Viewer height | 85-95 mm |
| Viewer depth | 45-50 mm |
Most important: keep lens centers about 64 mm apart and keep the phone screen about 40-45 mm behind the lenses. If the phone is too close or too far from the lenses, the image may look blurry.
Simple cut-and-fold design
You are making a rectangular viewer with three parts: front lens panel, middle spacer/tunnel, and back phone holder.
[eyes] -> [two lenses] -> [cardboard tunnel] -> [phone in landscape mode]
Build steps
1. Cut the main strip
Cut one cardboard strip 16 inches wide x 4 inches tall. Mark vertical fold lines at 1 inch, 5 inches, 9.5 inches, 14 inches, and 16 inches. Score the fold lines lightly so the cardboard bends cleanly.
2. Mark lens centers
On the lens panel, find the horizontal center. Mark two lens centers 64 mm apart: one 32 mm left of center and one 32 mm right of center. Keep both lens centers vertically centered.
3. Cut lens holes
Cut two round holes slightly smaller than the lenses. For 25 mm lenses, cut about 22-23 mm holes. For 34 mm lenses, cut about 30-31 mm holes.
4. Attach lenses
Place one lens over each hole. Use clear tape around the edge, hot glue around the rim, or a cardboard ring over the lens edge. Do not cover the center of the lens. Make sure both lenses face the same direction.
5. Build the spacer
Fold the cardboard so the phone screen will sit about 40-45 mm behind the lenses. Use tape to reinforce the fold lines.
6. Create the phone holder
At the back, make a simple flap or pocket. The phone should slide in sideways in landscape orientation. Use Velcro, a rubber band, binder clips, or a reinforced cardboard flap. Do not permanently glue the phone pocket closed.
7. Add a nose notch
Cut a shallow curved notch between the lenses at the bottom edge. Keep it small so the viewer stays sturdy.
8. Reinforce the viewer
Use clear packing tape around lens holes, fold lines, phone holder, outer corners, and the nose notch so the viewer survives classroom use.
How to use with SketchSpace VR
- Open SketchSpace VR on the phone.
- Load a demo or upload a student's photographed room template.
- Test the room normally first.
- Tap VR glasses or split view.
- Rotate the phone sideways.
- Place the phone into the cardboard viewer.
- Hold the viewer with both hands.
- Look around and explore the room.
Student viewing rules
- Sit down before using the viewer.
- Hold the viewer with both hands.
- Do not walk while viewing.
- Use the viewer for 1-2 minutes, then pass it on.
- Keep the phone secure in the holder.
- Use large drawings and short labels in SketchSpace VR.
- Remove the phone before handing the viewer to another group.
Best classroom setup
Use one viewer per group of 3-4 students. Students can rotate through drawing, photographing, uploading, viewing, and revising.
| 12 students | 3-4 viewers |
|---|---|
| 20 students | 5-6 viewers |
| 24 students | 6-8 viewers |
| 30 students | 8-10 viewers |
Cost estimate
| Recycled cardboard + purchased lens pair | $1-$5 per viewer |
| Purchased cardboard sheets + lens pair | $3-$8 per viewer |
| Prebuilt Cardboard-style viewer | $5-$15 each |
| Class set of 8 DIY viewers | about $25-$60 |
Buying checklist
For a DIY class set, buy in this order:
- Biconvex lens pairs, 45 mm focal length
- Corrugated cardboard sheets
- Velcro dots or strips
- Large rubber bands
- Binder clips
- Clear packing tape
For a faster ready-made setup:
- Google Cardboard V2-style viewers
- Alcohol-free lens-safe wipes or microfiber cloths
- Number labels for classroom checkout
Teacher notes
SketchSpace VR works best when students use large drawings, strong color, short labels, one clear idea per panel, simple arrows or symbols, and high contrast between text and background.
Avoid tiny handwriting, crowded diagrams, pale pencil-only drawings, long paragraphs, low-light photos, and crooked or uncropped uploads.
The cleaner the photographed template, the better the virtual room will look.
Best overall recommendation
Use 25 mm or 34 mm biconvex lenses, 45 mm focal length, a simple handheld cardboard viewer, a phone in landscape mode, no strap, and no magnet.
This keeps the viewer cheap, safer for classroom rotation, easy to build, easy to repair, and good enough for short SketchSpace VR viewing turns.