> For the complete documentation index, see [llms.txt](https://docs.imerit-prod.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.imerit-prod.io/annotation-tool/key-features/raycaster-and-frustum.md).

# Raycaster and Frustum

To identify objects swiftly while in the labelling process, the annotation tool provides the following two features:

## Raycaster

Raycaster is the point projection of the cursor coordinates in the [point cloud](https://docs.imerit-prod.io/annotation-tool/key-features/pages/t1P8d2reKe3nZWAkN2Kh#id-4.-point-cloud) over the images in the[ image panel ](https://docs.imerit-prod.io/annotation-tool/key-features/pages/t1P8d2reKe3nZWAkN2Kh#id-5.-image-panel)to help annotators identify the object swiftly. It appears as a 'red dot' over the camera images while hovering the cursor over the points in the point cloud. 

<figure><img src="https://lh7-us.googleusercontent.com/docsz/AD_4nXd4EPBCFL32xBFzei1wNXLWye9vQctxyOyZS3sBeLGJ1Mw328NaZ2194zfITcklySmtdqSclF3uxaN9ToKAv13Odxb-NSWNx_9K_G-qdYYkZ2V_4PH_1JTAezFco8tifTCf1mACeX8BRC50hgLIhdM-js2Q?key=lGhAQLv5xC3Ciuwf6zBTGQ" alt=""><figcaption></figcaption></figure>

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## Frustum

Similar to the [raycaster](#raycaster), frustum is a 'red cone' that appears on the [point cloud](https://docs.imerit-prod.io/annotation-tool/key-features/pages/t1P8d2reKe3nZWAkN2Kh#id-4.-point-cloud) while hovering the cursor over the images in the[ image panel ](https://docs.imerit-prod.io/annotation-tool/key-features/pages/t1P8d2reKe3nZWAkN2Kh#id-5.-image-panel)to give the user an understanding of what direction the camera is facing.

<figure><img src="https://lh7-us.googleusercontent.com/docsz/AD_4nXeqC3lTkYuXy4WSNAWCS8sJuRBxLdIc-0wOkDUFZ4NcROphHC4jeUAbGbbUPxKiQTo4ZKWQLUeMTzq5rH7sXBtekRINoiK3NrIVmuCnihQosshL-6sgShTGudb8d9DEPcujZFP8eLwOopw6b9m0Uznfmfc?key=lGhAQLv5xC3Ciuwf6zBTGQ" alt=""><figcaption></figcaption></figure>