Espermaschine wrote:Had a look at two videotutorials, Tav's manual and the fabric tutorial on Tav's blog.
(mentioned tutorials:
Tav's 1stTav's 2nd)
I can do the Dropshadow mini-tutorial and i do get a few things because of similarities in Gimp (bumpmapping, displacement-map), but thats about it.
For example i dont get the concept of 'Background Image' and 'Source Graphic'. Is that a z-order thing ?
Why two different terms (image and graphic) ?
The manual says, the background image is the region under the filter...
I always use the source graphic for the start as the others doesn't all work.
You can get to the source's alpha by a fecomposite from the source graphic, and sadly you cannot use individual filter primitives on the stroke and the fill, so that is a placeholder. At least that's what I heard from Suv at the live chat in the past.
Also, when i look at your goldtextures, there are several instances of 'Composite' and 'Color Matrix'.
It all seems so chaotic and im unclear on what to link with what and why.
When do i link to an effect, and which one, and when to the source image ???
As you may have seen in the video I'm not that experienced with it either as I often have to change the ordering of the inputs to that primitive.
The "in" option should use "A" source's alpha values and display the other "B" connected source only where "A" is opaque.
Knowing that, you can sort out and correct it if the result is not rendered as you intended.
Atop/Over also should be "self explanatory" although I'm not sure about the exact difference between them.
Maybe they are the same except for the source/connection ordering? Use them if you want to display one of the sources above the other. (As in z-ordering.)
The arithmetic option is also helpful time to time.
With that, you can "change the opacity of the source on top of the other one fully opaque below"
Can have multiply and similar effect yet that is how I use it mostly.
This image is showing it in action.
I use the colormatrix for lightening/darkening the source a bit and sometimes for hardclipping the alpha values of the source too.
That is by editing the last row, from
0; 0; 1; 0 to like 0; 0; 8; -3; 0. Needs try and error for fine tuning, as with most of the other filter primitives.
How to know "what you are doing" when editing a filter?
In general it is driving blindfolded as there is no preview of each of the primitives individually and the editor doesn't help much unconnecting and connecting in a different structure.