The Affinity Photo Twirl filter is found in the distort category. It can be used to create amazing distortions effects with any image as well as text and can be used in combination with channels as well as used with others as well as combined with other effects as well as used to modify brush strokes in the application and used with tools found in the toolbar and the result of the work can also be copied into Designer as well as Publisher.
The tool has two options: angle and radius. You can also set the position of the origin to create warps in any location on the image. You can also use the interactive settings to create interesting designs. The weird thing is that the default settings generate no warping effect and only when you modify the origin as well as change the angle / radius settings that you will see something and the result can be quite dramatic when applied to images as well as layers etc. The origin is not available on the panel and can only be applied interactively to the artwork. Click on the document and drag and as you do that you will see the origin and the effect modify as you use the mouse. It should be noted that the end result really does depend on the layer or the background being used.
You can use the tool on layers and that can be used to create unusual distortions of layers for combinations (the effect takes into account the transparency of the layer). If you apply it to the background then you will get an amazing distortion but apply it to a smaller layer or a shape etc (the shape will be converted to a pixel layer as the tool can only be used as a pixel layer) then you can create all kinds of unique artworks. The distortion can then be applied again and again to any layer via the repeat feature at the top of the filter menu to create some wow artwork. The layers can then be duplicated and modified in infinite ways
Use with layer effects such as 3D and shadows via the fx button at the bottom of the layers panel or you can access the panel via the right click on the layer itself and select the layer effects command. You can then add a blur / bevel etc to the artwork.
The tool can also be used with channels to create interesting red and green and blue color effects. You can access the channels via the view menu and studio and when you have the panel, simply select the red channel or the lab or cyan etc channel depending on the current color mode for the document and then apply the effect to that and the great thing is that the effect settings can be different for each channel and you can also combine it with selections and other effects per channel as well to create even more amazing work. You can then combine them all back into the single RGB image by clicking the circular icon at the top of the channels panel.
The effects is also available via the live layer menu and can be used as a layer effect to modify a particular layer or all layers. The live layer can be removed as well as duplicated to create many different interesting and unique distortions. The great thing about the live layer is that you can always double click the entry in the layers panel and change the settings at any time so the radius and the origin etc can be altered though it should be noted that the origin appears not to be stored so that has to be re-set. The live option also means you can change the blending mode for the effect so the resulting difference / darken / lighten etc can create even more amazing designs and the opacity can be used to lower the impact of the warping.
You can also distort text with the live effect layer, so the text can be distorted in 1000s of ways (it is a much better approach than using the destructive effect approach). The text can be modified with one layer effect or multiple to perhaps distort different parts of the text image. As the text and the effect are both live, you can still continue to edit the text.
You can also add the amazing tool to the toolbar for quick access (destructive effect). Go to the view menu and then customize tools and then drag the icon to the toolbar and then use the twirl tool as you would any other tool. The panel still appears and you have to set the origin as well as the radius etc.
You can also use the effect with pattern layers. Convert any image into a pattern layer via the layer menu and current selection command. You can then select that layer and then apply the effect to that via the toolbar or via the menu (destructive or non destructive) and modify the artwork. It works best if you set the layer to mirror otherwise you will end up with some extreme seam designs which you may or may not like. You can also duplicate the design and apply different distortions to each layer and then combine them using blending modes.
You can also record the result of any application of the warp to a path or image via the macro channel. Simply go to that panel and click the record button and then steps with this tool will be recorded and then you can playback the effect and it can be applied to the same artwork or a different piece of artwork or perhaps text etc
You can also use the powerful effect with layers that are linked. Linked layers is perhaps one of the most powerful features in the application and can be set via the layer menu and duplicate linked. Once you have do that with layers, any change to the pixel information such as this effect is then replicated in all the layers and some truly wow imagery can be generated using converted shapes and text etc as well as images.
You can use it with selections, create a selection using the marquee tools or the features in the select menu and also perhaps feather the design via the select menu. Once you have this, apply the effect to that selections or perhaps invert it and apply to that instead of use different settings in combination. You can also take the result of it being applied and copy and paste to create unique layer designs which can be modified further using the spin. The selection is also useful for creating a spiral design
Create a layer via the layer menu and go to the elliptical marquee tool and feather set to about 40 and apply the selection and hold the shift down and new and then add a gradient to that (linear). Go to the command to apply the effect as normal and you will see a blurry spiral gradient design. Go to the select menu and deselect. A very quick spiral. You can create infinite variations of this by adding different designs, brush strokes etc within that circle and spinning those as well via the command.