Displacement map option to copy pixels instead of warping

ID:2937005
 
Jul 15, 11:52 pm
Resolved
The displace filter now accepts a flags argument, with FILTER_OVERLAY as the only supported flag. If used, the displaced pixels will be overlaid on top of the original image.
Applies to:DM Language
Status: Resolved (515.1643)
This issue has been resolved.
It would be very useful for some shadowcasting effects to be able to set displacement map to copy pixels instead of pulling them.
Jul 16, 1:59 am
+1, would be cool
Jul 25, 1:44 pm
I don't quite follow what you mean. How would you define "copy" here?

The way the displacement filter works is that it reads the mask to figure out a direction, and the shader just says "grab the pixel from over there".
Jul 25, 2:06 pm
In terms of how displacement filter works, "copy" will probably mean "grab the pixel from over there and left a copy of it there"
Jul 25, 2:08 pm
Or, maybe, in other words, "don't grab but copy the pixel from over there"
Jul 25, 10:01 pm
In response to Vallat
Vallat wrote:
In terms of how displacement filter works, "copy" will probably mean "grab the pixel from over there and left a copy of it there"

That doesn't make sense.

When the displacement filter is grabbing a pixel from somewhere else, that somewhere-else—if it's covered by the mask as well—is also doing that. Every pixel under the displacement mask is using that mask, independently of one another.

If you want pixel A to copy pixel B due to displacement, but pixel B to be left alone, then at pixel B's location the displacement mask has to be neutral.
Aug 19, 7:57 pm
Lummox JR resolved issue with message:
The displace filter now accepts a flags argument, with FILTER_OVERLAY as the only supported flag. If used, the displaced pixels will be overlaid on top of the original image.