# Underwater photogrammetry

**URL:** <https://forums.unrealengine.com/t/underwater-photogrammetry/1483722>\
**Category:** Photogrammetry\
**Tags:** question, realityscan\
**Created:** [December 5, 2023, 3:05pm UTC](https://forums.unrealengine.com/t/underwater-photogrammetry/1483722 "2023-12-05T15:05:02Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![amfram](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@amfram](https://forums.unrealengine.com/u/amfram)\
**Post date:** [December 5, 2023, 3:05pm UTC](https://forums.unrealengine.com/t/underwater-photogrammetry/1483722/1 "2023-12-05T15:05:02Z")

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Hi

I’m trying to model a stone dock in Reality Capture using underwater images captured with a Blueye Pioneer ROV. It uses a 1/3 inch CMOS wide angle sensor.

It looks like RC are managing to stich a lot of the images together but with a massive banana effect. The dock is supposed to be straight. I’ve tried all the different Distortion models in the in the Alignment settings, but the model stays more or less the same. I have left the “Camera model” on “no lens distortion”.

 ![Model_BryggenBergen](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/a/b/2abd16b93440155eb1a064eeec5c9ccca3650931.jpeg)

![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/b/0/8/b08e8f6cbfe2edffa796e18c1f3b02a87f61eb47.png)

 ![AlignementSettings_BlueyePioneer](https://d3kjluh73b9h9o.cloudfront.net/original/4X/1/a/7/1a76a5ec9148e9b8846106b9764c37501d346b59.png)

Does anyone have an idea of what I should try next?

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<div class="post-metadata">

**Author:** ![OndrejTrhan](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/ondrejtrhan/32/906565_2.png) [@OndrejTrhan](https://forums.unrealengine.com/u/OndrejTrhan)\
**Post date:** [December 5, 2023, 3:13pm UTC](https://forums.unrealengine.com/t/underwater-photogrammetry/1483722/2 "2023-12-05T15:13:50Z")

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Hi [amfram](https://dev.epicgames.com/community/api/user_profiles/tab-redirect/about?discourse_username=amfram),  
you can try principles from this article: [Tutorial: Banana Effect - What To Do If My Model is Bent](https://forums.unrealengine.com/t/tutorial-banana-effect-what-to-do-if-my-model-is-bent/790591)  
Mostly the option using precalibrated images (images with fixed calibration parameters)  
Also, capturing not just in two lines could help and using some control points.