Image masking tests (Update2)

Started by bigben, February 06, 2007, 10:27:05 PM

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Hi All

I've started documenting my image masking tests and decided to post it online as others will probably find it useful as well. It's more of a reference than a tutorial at the moment although I intend to accompany it with some additional files as I do some more tests. (1.2Mb)




Very cool stuff.This is already a very useful pdf! I hope you keep on building it up to a classic resource. My I ask if you could share how you got the images to be zoom friendly? Whenever I make a pdf the images are not zoom friendly! Meaning they will get pixelated very fast...

Thanks man


I normally set the images to resample to 150dpi for the PDF with medium JPEG compression (Standard default setting for Acrobat now). It's a reasonable trade off between size and quality. The PDFs are also optimised for web delivery, which makes looking at larger PDFs online easier (you can go straight to page xxx without having to download all of the previous pages).

The document bookmarks are auto generated but I'll also add a table of contents once it gets bigger.



Interesting.  Thanks for sharing. - A great Terragen resource with models, contests, galleries, and forums.


Hmmm...the pdf doesn't open?
I'm currently at work, working on a prehistoric machine, so maybe back at home I'll be more succesful in opening it  ;D


The PDF opens for me.. great start to the tutorial, hope to see more of it as its only a beginning...

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The world is round... so you have to use spherical projection.


Yes it's only a start, but I'm now working on fine-tuning some of the things I've experimented with so far  and documenting it in case I forget later on.  ;)  I'll make files available on a per section basis to keep the download sizes in reasonable chunks. That way people only need to download the files for the specific section they're interested in. My next tests include:

  • Finalising my leaf colouring hack for trees
  • A study of the combined effects of TG's antialiasing and image resolution for optimising mask image resolution
  • Creating multiple lakes (and filling them individually with water)

Here's a sneak peak at an autumnal XFrog birch leaf (another update posted... forgot to unmask the stems) and the original leaf texture (after I bumped up the contrast).

Working "in situ" was a bit of a pain with render times so I just setup a correctly scaled image map to work on. This was much easier. I kept my previous colouring methods (with a few tweaks) but the shading wasn't working the way I wanted it to so I went back to the drawing board. I'll try it out on some trees tonight.


OH WOW! That looks quite natural, be interesting to see if the major hue overwhelms the more subtle hues or not in bulk.


I'll post an update after I do a normal render of some trees. After that, it's going to get tricky. In theory you want to be able to get 3 levels of detail... leaf detail, an overal hue for each tree, and variations in hue across a forest... which is the main reason I started on this approach. But that's a surfacing project and this doc is focussing on image masking ;)


Very useful, thanks for sharing bigben!


Quote from: RedSquare on February 07, 2007, 07:17:27 PM interesting to see if the major hue overwhelms the more subtle hues or not in bulk.

I've started on the tree and have been going through this in my mind. I usually build up my surfaces with a gradual reduction in both coverage area and intensity so in theory the major hues shouldn't get overwhelmed by the finer details. I may have to re-order the colours for each successive layer. The render times are pretty long (12 hours for 800x400, unmodified tree at highest quality) so it'll be a couple of days before I have a result to show.


For those who haven't noticed I tend to "think out loud" a lot when I'm working on a project so that someone who knows better can steer me in the right/alternative direction.

I went back to my leaf surface test and tiled the image masks rather than wait for a long render of trees. It works!  :)


  • "Real" tones applied via two image maps ('Base image' and 'Image Colour mask')
  • Large colour variation via two primary shaders (red and yellow)
  • Finer detail via child layers (Colour tintX). Child applied to all primary shaders
  • Finetuning of shadows via "Image colour mask" which in theory should be applied to all colour shaders but I've only applied it to the primary shaders

It'll look slightly different when it's applied to the object as a lot of the alpha masks are to simulate the object's alpha channel. From here it's just a case of scaling the  fractal breakups to set the variation to forest, tree or leaf scale.


Woah, this is some great stuff here!  Nice work.
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Although I got kinda lost in you node network but I have to say....WOW!!!

keep it up!

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