# Alpha blending parameters for TDrawableImage.DrawFrom

**URL:** <https://forum.castle-engine.io/t/alpha-blending-parameters-for-tdrawableimage-drawfrom/1914>\
**Category:** Uncategorized\
**Created:** [May 18, 2025, 6:10pm UTC](https://forum.castle-engine.io/t/alpha-blending-parameters-for-tdrawableimage-drawfrom/1914 "2025-05-18T18:10:05Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Noscow](https://forum.castle-engine.io/user_avatar/forum.castle-engine.io/noscow/32/964_2.png) [@Noscow](https://forum.castle-engine.io/u/Noscow)\
**Post date:** [May 18, 2025, 6:10pm UTC](https://forum.castle-engine.io/t/alpha-blending-parameters-for-tdrawableimage-drawfrom/1914/1 "2025-05-18T18:10:05Z")

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Good day!  
I’m a little confused trying Alpha blending with `TDrawableImage`.

For now alpha blending is off. And my textures seems like:

 ![alpha](https://forum.castle-engine.io/uploads/default/original/2X/7/796cbc1dc6c4d29ea85b1398ef5ae1c875edaa37.png)  
I think you see that trees borders are transparent. So, background sea and sky is visible through the forest.

As I understand, property `TDrawableImage.Alpha` works when texture is render. But I need it in texture construction process: every tree is `TDrawableImage`. And I draw they on texture - another `TDrawableImage`.

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**Author:** ![michalis](https://forum.castle-engine.io/user_avatar/forum.castle-engine.io/michalis/32/3_2.png) [@michalis](https://forum.castle-engine.io/u/michalis)\
**Post date:** [May 18, 2025, 11:29pm UTC](https://forum.castle-engine.io/t/alpha-blending-parameters-for-tdrawableimage-drawfrom/1914/2 "2025-05-18T23:29:17Z")

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`TDrawableImage.Alpha` affects rendering of the given image, indeed.

If you want the trees to be opaque, set `TDrawableImage.Alpha` (on the _source_ image that is drawn, not destination; i.e. on the tree, not on background) to `acNone` during drawing. This affects rendering the texture to the screen, or to another texture.

I hope I guessed the issue right – if this doesn’t help, please attach a testcase to reproduce the problem. I would have to see what do you mean by “For now alpha blending is off.”, and what did you expect to see instead 🙂

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**Author:** ![Noscow](https://forum.castle-engine.io/user_avatar/forum.castle-engine.io/noscow/32/964_2.png) [@Noscow](https://forum.castle-engine.io/u/Noscow)\
**Post date:** [May 23, 2025, 7:00pm UTC](https://forum.castle-engine.io/t/alpha-blending-parameters-for-tdrawableimage-drawfrom/1914/3 "2025-05-23T19:00:11Z")

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I tried to make example application, but transparency works without problems 🙃  
Maybe I just draw my tiles borders more accurate and it will help.