GIMP Version: 2.8.10
Operating System: Mac OS
GIMP Experience: Beginner Level

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Ok is it me? (LOL... yeah we know it most likely is... ) or is Gimp buggy and/or are the displace bump map f/x inconsistent?

Ever since Wallace showed me how to create the texture f/x for the t-shirt mock-up question I posted awhile back I've been making some progress (Thanks Wallace )

However, sometimes i can't seem to get the maps to work.

Here's what I do:

1. I've been using the same maps I created for the same t-shirt template i've been using to make t-shirt mock-ups.

2. I have made sure to "Layer Image To Size"

Still I have gotten VERY inconsistent results too often sometimes. Ranging in results from ZILTCH to awesome. What I don't understand is why wouldn't the f/x apply to any text related design I assign it to? (they are all just simple text designs. )


I did notice something odd things after repeating the same steps for like 10x over and over.
I saw some significant changes (not sure why it suddenly happened...)

I also noticed how sometimes it shows more options (files ...) to choose from.
Then sometimes it doesn't show the actual maps I created!

The displacement map filter will allow you to use any layer of any open image that is the same size as the layer you are calling the filter on.

-RobA>

Hmmm... yes true.

So if technically if I layer to same size the design/image then it should work.

I notice when I open up a previously created .xcf file that has both map files and all other image files in it already and then import my new design it seems to have problems with the displace and/or bump mapping effect.

Should the i also layer to same size the image i've already made a map of?

As RobA said, the displacement filter requires the map be the same size, so any open image/layer that's the same size will be available in the displacement filter's dropdowns. The bumpmap filter doesn't require that the map be the same size, but in most cases, it makes sense for the map to be the same size. It just depends on what you're trying to accomplish.

Bump mapping ignores the alpha channel. Typically the color of transparent pixels is black (it doesn't have to be) and so a common problem arises when trying to bump map against a layer containing black text (as shown in your screenshot). Since the (transparent) background of the black text is also black, you are basically bump mapping against a solid black layer, resulting in what you describe as "ZILCH".