Is there a decent filter to make some sort of lens distortion for text ?

[Espermaschine]

I wonder if one could use Inkscape's tiled clones tool to make that bulged grid.

Like this (but its probably not that sine-distribution):

   

[rich2005]

@ofnuts / espermaschine

This a quickie just using bumpmaps.

   

When is it better to use a displacement map? Always? sometimes? special circumstances?

[Ofnuts]

Different animals... Bump doesn't move pixels, it only adds shading.

   

[Espermaschine]

(11-05-2016, 11:47 AM)rich2005 Wrote: @ofnuts / espermaschine

This a quickie just using bumpmaps.



When is it better to use a displacement map? Always? sometimes? special circumstances?

I dont understand what you are demonstrating with that image.

[rich2005]

bulging, rounded

Maybe not the best example, but when is a displacement better / more appropriate than a bump map?

I understand the difference between shading and moving pixels but in the context of the thread I would really appreciate your thoughts on your image results.

[Espermaschine]

Hmm, well bumpmapping is for bevels (shading). To a certain extent you can make the bulging without any shading.
If you think of the bulging coming from text being reflected in a convex mirror, it would get distorted and blown up (thats where, theoretically speaking, a displacement map would come into play).
https://en.wikipedia.org/wiki/Curved_mirror

So i think the letter 'I', displayed as a rectangle would look like this:

   

And i think the Lens Distortion filter in Gimp realized that quite well, after i made the perspective distorted letters in Inkscape.

(11-05-2016, 06:16 PM)rich2005 Wrote: I understand the difference between shading and moving pixels but in the context of the thread I would really appreciate your thoughts on your image results.

My shading isnt very accurate. But it fools you to a certain extent, that it maybe is

(11-05-2016, 11:47 AM)rich2005 Wrote: When is it better to use a displacement map? Always? sometimes? special circumstances?

This tutorial is a very good example what you can do with a displacment map

[rich2005]

Ok, understand all that,

Just wondering how you got from image 1 to image 2 in post #5 by using a displacement map as generated by ofnuts 2 gradients.

[Espermaschine]

(11-05-2016, 07:13 PM)rich2005 Wrote: Ok, understand all that,

Just wondering how you got from image 1 to image 2 in post #5 by using a displacement map as generated by ofnuts 2 gradients.

I didnt
I was hoping it would be possible with a displacement map, because it seems logical and it still may be in the context of filter writing.

Instead i used 'Lens Distortion' but on top of the distorted text made in Inkscape.

But for now, warping text into the shape as reflected by a convex mirror and getting good results is not possible at this time in Gimp.
We would need new filters for that

[rich2005]

Not Gimp, Imagemagick and one of freds IM bash scripts, bubblewarp using default settings.
before and after

   

Usually very difficult to rework for Windows.

[Espermaschine]

(11-05-2016, 09:23 PM)rich2005 Wrote: Not Gimp, Imagemagick and one of freds IM bash scripts, bubblewarp using default settings.
before and after

WOW !!!!!!!!!!

Quote:Usually very difficult to rework for Windows.

Oh