Table of Contents

CRS FAQ

Below are common questions and answers regarding the use of the image cloud recognition feature.

Q: Does CRS support loading 3D models/virtual content from the cloud?

A: Yes, CRS supports loading 3D models/virtual content through the following methods:

  • meta attribute: Store AR content in the target image's meta field as a text file. 3D models can be Base64-encoded as text or saved as cloud storage URLs (e.g., Alibaba Cloud OSS, AWS S3).
  • Loading process: After the client retrieves the meta data from CRS, use a 3D engine (e.g., Unity, Three.js) to parse and load the model.
  • Reference documentation: See Create recognition target | POST /targets.
Note

For large files (>2MB), use URLs to avoid oversized request bodies caused by Base64 encoding.

Q: Are there recognition limits for CRS?

A: There is no total recognition limit, but tiered concurrency levels exist:

  • Basic mode: Suitable for applications with QPS < 50. No strict limits but adherence to fair use policies is required.
  • High-concurrency mode: If QPS ≥ 50, upgrade to dedicated-resource cloud services to ensure recognition stability and low latency.
Important

If your application may experience temporary concurrency surges during holidays or large events, contact EasyAR technical support at least 3 working days in advance to request a service upgrade.

Q: Why does the Web Service API return 404?

A: A 404 error typically indicates that the requested URL path doesn’t exist or the resource wasn’t found. Common causes include:

  • Incorrect URL format: Accessing a non-existent endpoint. For example, directly accessing http://your_crs_uuid.na1.crs.easyar.com:8888 is invalid. Use a full endpoint like http://your_crs_uuid.na1.crs.easyar.com:8888/ping.
  • Empty recognition results: When calling the /search API, if no target is matched, it returns 404 with the message body No result: there is no matching.

Troubleshooting steps:

  1. Confirm the URL spelling is correct, including the UUID and port.
  2. Use the /ping API to test service availability.
  3. Check if request parameters are complete (e.g., image data, API Key).

Resolution: If /search returns 404, the current image didn’t match any target. Guide users to adjust the shooting angle or verify if the target has been uploaded to CRS.

Q: What causes common Web Service API error codes?

A: Besides 404, the following error codes are frequent:

  • 400 invalid appId (appKey)

    • Cause: The requested Key is incorrect or signature verification failed.
    • Troubleshooting: Verify your Key was copied from the CRS gallery; ensure POST requests include a full signature; confirm parameters use Content-Type: application/json.

  • 400 invalid date

    • Cause: The request timestamp is invalid or deviates significantly from server time (typically requiring ±5 minutes).
    • Troubleshooting: Check device time accuracy (especially timezone settings).

  • 415 unsupported media type

    • Cause: HTTP Header lacks Content-Type: application/json, or the request body format is incorrect.
    • Troubleshooting: Ensure POST Headers include Content-Type: application/json and the Body is valid JSON.

General advice: All CRS API requests must strictly follow the CRS API documentation.

Note: This FAQ covers high-frequency issues in CRS usage. To report new issues, please contact us!