I often find that I’m converting from layers to images or objects because I can’t find a node that will do the thing I want it to otherwise.
-It doesn’t seem possible to change the size of an image. There’s no transform image node. Resize image will pixellate the image but won’t have the same effect as transform layer.
-It doesn’t seem possible to process the layer with regard to visual effects. It therefore has to be changed back to an image. For example, imagine you want to change the hue of some copied layers.
-It’s mostly easier to work with objects when making shapes and things, even if you want to make 2d shapes, so then I end up converting object to layer.
As I go on to write more complex compositions, I can easily imagine changing back and forth between these three modes many times within the composition. So my question is, does it really matter if I switch modes a lot? Or is it better to keep it to the minimum because of CPU? Should I try and find workarounds to keep things in the same mode or should I just change back and forth casually?
I think Vuo would benefit tremendously for ease of use by new users in making these types explicit and even changing the wire thickness/dashes or port shapes to make this more explicit.
Images are bit format. Scenes, shape objects and layers have their unique structural definitions. It’s not clear to the new user how to proceed a lot of the time given the large number of processing nodes that are specific to one or another data type. It’s a catch 22, until you learn about all of them your end up chasing your tail a lot in Vuo in my experience.
In Vuo, images and layers really have different roles. Images are grids of pixels that you can manipulate. You can resize them (Resize Image, Resize Image if Larger), crop them (Crop Image, Crop Image Pixels) or apply any one of a number of image filters.
Layers are designed to be stacked on top of each other, a bit like layers in an app like Photoshop. You can create layers in Vuo, either from shapes or from an image, but you can’t load layers from a file. Layers are sized based on the Vuo coordinate system.
As you noted, images can be made into 3D objects.
It’s not computationally expensive to make a layer from an image. Creating a Layer or 3D Object from an Image (nodes like Make Image Layer and Make Lit Image Shader → Make Sphere) is computationally fairly efficient, since Layers and 3D Objects just keep a reference to the image you feed into it.
It is more computationally expensive when you start to create new images. One example would be creating an image from a group of layers or 3D objects, such as Render Layers/Scene to Image.
There is a tabled feature request Execution time, which includes a composition (which can be packaged as a subcomposition) for testing the execution time of a node or group of nodes in a composition. This might be helpful as you examine your own compositions.