02-28-2018, 11:53 PM
Thanks for helping me with concepts / phrasing-this-correctly.
If you want to skip reading a bit of detail you can jump to the bottom of this post and start reading at "*** My goal is ***"
I'll add some more detail, and explain it differently, here are the steps:
- Have an image01 and a layer01, say 1000 x 1000 pixels
- I draw on layer01
- Copy layer01 to layer02 using pdb.gimp_layer_copy()
- Note: Now both layer01 and layer02 are 'exactly' the same
- Use these functions on layer02
pdb.gimp_image_select_polygon()
pdb.gimp_selection_invert()
pdb.gimp_edit_cut()
pdb.gimp_selection_invert()
to cut away and keep a polygon in the cener of layer02, say 900 x 900 pixels
At this point, if layer02 is above layer01, and I am viewing 'both' layers. The view that I want is as if I am viewing 'only' layer01.
This does work (why would it not?)
So, at this point, there are no issues with 'intermediate colors (that) are due to this partial opacity blending with whatever is in the background'.
Here is the problem:
I use pdb.gimp_hue_saturation() with appropriate arguments to make a given layer darker than the one above. This part 'making layers darker' does work. The thing is I see more than just one layer being darker than the one above. I see a lighter border around the layer, and this border is lighter than the layer, and lighter than the layer below. So it is like I have a light line draw around each layer. This makes the transition from dark to light less subtle.
*** My goal is ***
- Render on a layer, and do processing to make it look darker at the edges
*** Steps ***
- Draw on one layer, copy this layer to other layers
- cut so that, from bottom to top, each layer is a smaller piece of the layer below (no scaling is involved)
- darken using pdb.gimp_hue_saturation(), so that from bottom to top layers go from being dark to light
Maybe there is a another way to do this, but these steps give me good control of size and darkness.
All is ok except for the lighter lines that I see around each layer, which makes the transition from dark to light less subtle.
I tried gimp-selection-sharpen(), it did not seem to help.
Saurabh
If you want to skip reading a bit of detail you can jump to the bottom of this post and start reading at "*** My goal is ***"
I'll add some more detail, and explain it differently, here are the steps:
- Have an image01 and a layer01, say 1000 x 1000 pixels
- I draw on layer01
- Copy layer01 to layer02 using pdb.gimp_layer_copy()
- Note: Now both layer01 and layer02 are 'exactly' the same
- Use these functions on layer02
pdb.gimp_image_select_polygon()
pdb.gimp_selection_invert()
pdb.gimp_edit_cut()
pdb.gimp_selection_invert()
to cut away and keep a polygon in the cener of layer02, say 900 x 900 pixels
At this point, if layer02 is above layer01, and I am viewing 'both' layers. The view that I want is as if I am viewing 'only' layer01.
This does work (why would it not?)
So, at this point, there are no issues with 'intermediate colors (that) are due to this partial opacity blending with whatever is in the background'.
Here is the problem:
I use pdb.gimp_hue_saturation() with appropriate arguments to make a given layer darker than the one above. This part 'making layers darker' does work. The thing is I see more than just one layer being darker than the one above. I see a lighter border around the layer, and this border is lighter than the layer, and lighter than the layer below. So it is like I have a light line draw around each layer. This makes the transition from dark to light less subtle.
*** My goal is ***
- Render on a layer, and do processing to make it look darker at the edges
*** Steps ***
- Draw on one layer, copy this layer to other layers
- cut so that, from bottom to top, each layer is a smaller piece of the layer below (no scaling is involved)
- darken using pdb.gimp_hue_saturation(), so that from bottom to top layers go from being dark to light
Maybe there is a another way to do this, but these steps give me good control of size and darkness.
All is ok except for the lighter lines that I see around each layer, which makes the transition from dark to light less subtle.
I tried gimp-selection-sharpen(), it did not seem to help.
Saurabh