Raster/rasterize/rasterise@

[newbie2]

Hello everyone,

 

A couple of months in now and am progressing well.

 

However, am confused over what a raster layer is/ rasterise.

 

Why/when would this be used.

 

Would be very grateful for a simple explanation please.

 

Many thanks.

 

[A_B_C]

Hi newbie2,

maybe these older posts will help you (perhaps the whole threads are worthwhile reading):

https://forum.affinity.serif.com/index.php?/topic/13651-layers-and-masks-concepts/?p=60276

https://forum.affinity.serif.com/index.php?/topic/13815-couple-of-questions/?p=66856

Cheers, Alex 

[newbie2]

Thanks Alex - this does help.  Am still only at the pixel layer, but now I know that I do not have to concern myself with rasterise until I become more proficient and experiment with image and object layers. 

 

Once again, thank you.

[A_B_C]

No, it is not that difficult …  :)

 

Basically, you can think of rasterising as a process of taking information from a certain source and transform it into pixel information. The outcome of a rasterising process will always be a pixel layer. And the basic parameters for calculating the pixel information are taken from your document and the respective source. There are at least four main areas of applying the rasterising process:

• Placed objects
• Vector objects
• Layers with modifiers like masks, effects, (live) filters, or (live) adjustments
• Pixel layers

Let me quickly describe these applications one after another:

• Whenever you place an object in a document, it will show up as an image object there. The placed object will retain most of its properties, such as the native resolution, while some of its properties get changed, such as the colour profile. Rasterising an image object will turn this object into a pixel layer, thereby stripping the original properties from the object and rendering it at its current size into the document.​
• Whenever you rasterise a vector object, such as a curve or a dynamic shape, the vector object will be rendered into your document as a pixel layer. Since the vector information will be transformed into pixel information, you will loose the editability that is typical for vector objects, but you will gain all the editing options that are typical for pixel objects. For example, you can make pixel selections now or use the eraser on your new layer.
• Now suppose you nested modifiers like masks, effects, (live) filters or (live) adjustments to a layer of any type. Then these modifiers will appear as children of your layer in the layers list. When you rasterise the layer, the information that is contributed to the layer by the modifiers will be merged with the information provided by the layer itself, and the outcome will be once again a pixel layer. Rasterising a layer with a lot of modifiers applied will free system resources, since these effects don’t have to be calculated anymore. But you will loose the option of editing the parameters of the applied modifiers.
• Finally, suppose you have a pixel layer that overlaps the document boundaries. By rasterising the pixel layer, you will in effect trim that layer down to the document size. The overlapping areas will be lost.

Furthermore you must be aware that some other processes require the rasterising of layers beforehand, like the application of certain effects. Hope these explanations make sense, and help to clarify the issues a bit.

 

Cheers, Alex  :)

[PixelNik]

Thank you, yes, this short explanation did help me very much.