# Different render performance between GUI and API

**URL:** <https://vapor.discourse.group/t/different-render-performance-between-gui-and-api/420>\
**Category:** Uncategorized\
**Created:** [November 4, 2024, 3:24pm UTC](https://vapor.discourse.group/t/different-render-performance-between-gui-and-api/420 "2024-11-04T15:24:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![WTYue](https://avatars.discourse-cdn.com/v4/letter/w/a3d4f5/32.png) [@WTYue](https://vapor.discourse.group/u/WTYue)\
**Post date:** [November 4, 2024, 3:24pm UTC](https://vapor.discourse.group/t/different-render-performance-between-gui-and-api/420/1 "2024-11-04T15:24:04Z")

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Hi,

I’ve been using Vapor to render images, and overall, it’s been a great experience. However, I’ve encountered a bit of an issue: the results rendered via the GUI and the Python API look different. As shown below, the first image was rendered through the GUI and saved using “Capture-Single image-PNG” – it’s quite detailed. The second image was created with the Python API using `RenderToImage()`, but it looks comparatively rough.

 ![2](https://global.discourse-cdn.com/free1/uploads/vapor/original/1X/505eefb7cf73a99b01a485d963f5a8457ae1b644.jpeg)

In the GUI, I set up the Transfer Function and saved it, then loaded this settings file when rendering via the API. I also used the same renderer and the same renderer parameters. Is there any refinement operation I may have overlooked in the API before generating the image?

Thank you!

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<div class="post-metadata">

**Author:** ![WTYue](https://avatars.discourse-cdn.com/v4/letter/w/a3d4f5/32.png) [@WTYue](https://vapor.discourse.group/u/WTYue)\
**Post date:** [November 4, 2024, 3:26pm UTC](https://vapor.discourse.group/t/different-render-performance-between-gui-and-api/420/3 "2024-11-04T15:26:15Z")

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Hi This is the API outcome.

 ![wind_farm_3d-600](https://global.discourse-cdn.com/free1/uploads/vapor/original/1X/47cfe84186048740706e990e1dd9e0a527d470bd.jpeg)

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**Author:** ![pearse](https://yyz2.discourse-cdn.com/free1/user_avatar/vapor.discourse.group/pearse/32/177_2.png) [@pearse](https://vapor.discourse.group/u/pearse)\
**Post date:** [November 4, 2024, 5:10pm UTC](https://vapor.discourse.group/t/different-render-performance-between-gui-and-api/420/4 "2024-11-04T17:10:58Z")

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Interesting. Could you share a data and session file so I can try to reproduce this?