# Screen('DrawTexture') with blurshader seems to do nothing?

**URL:** <https://psychtoolbox.discourse.group/t/screen-drawtexture-with-blurshader-seems-to-do-nothing/5330>\
**Category:** Programming Help\
**Tags:** windows\
**Created:** [April 17, 2024, 12:23am UTC](https://psychtoolbox.discourse.group/t/screen-drawtexture-with-blurshader-seems-to-do-nothing/5330 "2024-04-17T00:23:42Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![minjungkim](https://avatars.discourse-cdn.com/v4/letter/m/8e7dd6/32.png) [@minjungkim](https://psychtoolbox.discourse.group/u/minjungkim)\
**Post date:** [April 17, 2024, 12:23am UTC](https://psychtoolbox.discourse.group/t/screen-drawtexture-with-blurshader-seems-to-do-nothing/5330/1 "2024-04-17T00:23:42Z")

</div>

I’m interested in writing my own procedural shader and having it attached to a texture that I’d like to draw to the screen. I’ve been reading the help documentation in `ProceduralShadingAPI.m` and `Create2DGaussianBlurShader.m`, and have decided that my goal is to run something like this:

```auto
Screen('DrawTexture', win, mytexture, [], [], [], [], [], [], blurshader);

```

But when I make this call, I don’t see anything on the screen – as in, everything just looks black. There are no obvious errors in the console.

Here is some more info, per the posting guidelines:

1. Psychtoolbox Version:

```auto
>> [a, b] = PsychtoolboxVersion

a =

  0×0 empty char array

b = 

  struct with fields:

        major: 3
        minor: 0
        point: 19
       string: ''
       flavor: ''
     revision: 0
    revstring: ''
       websvn: 'https://github.com/Psychtoolbox-3/Psychtoolbox-3'

```

1. Platform: Windows 10

2. Matlab Version: 9.14.0.2286388 (R2023a) Update 3

3. Warnings and Errors: no obvious ones.

4. Hardware: NVIDIA GeForce RTX 3080. Driver from NVIDIA (Driver Date: 8/7/2022; Driver Version: 31.0.15.1702)

Thanks in advance!

---

<div class="post-metadata">

**Author:** ![dcnieho](https://avatars.discourse-cdn.com/v4/letter/d/779978/32.png) [@dcnieho](https://psychtoolbox.discourse.group/u/dcnieho)\
**Post date:** [April 17, 2024, 5:46am UTC](https://psychtoolbox.discourse.group/t/screen-drawtexture-with-blurshader-seems-to-do-nothing/5330/2 "2024-04-17T05:46:35Z")

</div>

Can you provide minimal code that we could run that shows the problem?