The Photoshop glass filter is found in the filter gallery and uses displacement maps PSD files to modify the effect and comes with a range of settings and can be combined with other effects
It includes only a few settings (if you want more you should be using After Effects etc). The options are distortion + smoothness + texture (this is the place for the selected PSD file) + scaling + Invert. Distortion: if you set the distortion to a very low setting you can hardly see the distortion with any displacement map. Set the distortion high for the glass and the displacement map can be seen as clear as day. Smoothness: Low, you can see more a thin line embossing effect. Set high and you see a nice smooth effect applied to the distortion (as long as the setting is high enough). Texture: this is the main area for the displacement maps PSD files. The displacement maps can be seamless tiles but they don't need to be and you can create many amazing artworks using non-seamless designs as well. You can only use displacement PSD files but you can always convert PNG or JPG files to PSD and then use those. Scaling: If you have a fairly large file then you may wish to set the scaling to a large value, if you are using a small source file then you may wish to reduce the scaling. It has a fairly limited range, not sure why the GF doesn't go beyond those minimum and maximum limits (Affinity Photo's versions of these effects often allows a far greater range of settings). Invert: changes the angle of the light to the opposite direction
One great feature of the gallery is that you can add additional effects within the same plugin dialog though there is no blending modes between each of the entries. You can delete the entries within the panel as well. You can also click on each entry and then modify the settings for that entry. To add an additional effect go to the bottom of the panel and click the '+' button and you will see another GF entry created with the same settings. You can then modify the settings as well as change the effect to perhaps another of the gallery effects such as Texturizer and patchwork etc. You can also select any of the entries and drag them up and down to create different results within the same panel.
As with all effects,it and multiple gallery effects can be combined together with others as well as with adjustment layers etc in an action and that action can be run multiple times via the actions panel. Record the effect action and then add into the mix other effects such as oil paint and camera raw and then save that to run the action on other designs such as type and images. The distortion effect can then be re-applied numerous times and combined with varying settings of scale and perhaps different displacement maps, to create all kinds of amazing distorted effects, colored distorted effects, subtle texture effects and more
It can be used to great effect with type. Apply some type and flatten and then apply it to that. It does not work well with type as a smart object or layer but it does work well with the artwork applied to a layer or background layer with something more than just the type to work with. You may find that you can create interesting type designs by blurring the type beforehand and then apply.
Go to the channels panel and select the red channel and then apply it with one set of settings, go to the green channel and use a different set of settings and same with the blue channel. You can also apply the effect multiple times to one channel as well as totally ignore another channel. Once you are happy with your result, click the RGB entry. If you are using CMYK or other image modes, you will notice that the gallery is not available.
You can select one layer in the layers panel and apply the GF with one set of settings. Select another layer and then apply it with a different set of settings and you can then combine those layers using different blending modes. The layers can be different images or they can be the same image duplicated or perhaps the image but slightly smaller than the lower layers. Or use with blending modes via the layers panel so the GF can be blended with difference and darken or lighten with the lower layers.
You can convert a layer into a smart object via the layer menu and smart objects and then apply it to that via the gallery. You can apply multiple effects to that layer and combine them using the blending modes for the smart filter. The great thing about the smart effect is that you can edit the effect at any time as well as delete it at any point.
You can apply the effect with the full settings but if you want a subtle effect you can always apply it and then go to the edit menu and select fade and then use the different blending modes such as lighten or change the opacity of the applied effect to reduce the impact. You can find it in the edit menu, never sure why they didn't stick it in the proper menu where it would be readily found such as with the repeat.
This is one effect that really doesn't work well with the repeat (found at the top of the menu) as it uses exactly the same settings as the initial apply. The distortion is great, re-applying the distortion to the distorted image with the same settings just ends up sort of a mess. Of course, this is a personal opinion but it doesn't really do much for me. Now, you can, apply another effect such as oil paint to the distortion and then go back to the original and re-apply it (though, sadly, the settings will have to be reset as there is no effect history panel).
Create a document say100 x 800 and set the background to white. Go to the rectangle tool and set to pixel mode and set to black and create a thin black vertical line, make certain it is only slightly smaller than the image. Save this design of a single line as a PSD file. Go to the gallery and select the effect and go to the texture entry and browse for the PSD file and select. Set the distortion and smoothness to high and set the as scale as required. And apply. You can repeat it but the result will be an even more intense distortion but with a lot of imperfections. You could also add others to it such as oil paint to smooth out the lines