[Award Winner] Yet Another Mountain Tutorial Using GIMP

[neilkal]

Can you offer any hints on how to get a nice tall volcano? I have the following but I'm not quite sure what to change to ensure that I get one tall peak in the middle. I thought it was the ridges, but that didn't seem to do it.

[kjdavies]

Off the top of my head, you might try a radial gradient fill instead of the angular. White in the center to black at the edges. You might also want to apply the gradient in a non-linear manner (or adjust the curve later). You'll also want to -- probably need to, really -- add some noise and blur to break up the sudden drops you'll get at the edges. The gradient generally won't go to zero there, so you'd end up with a bunch of sudden drops.

On that note, if you want the peak to be not quite in the center, apply a small displacement map to shift it. Don't go too big or you'll get what I call 'stretch marks'.

After that, continue as before to get the surface texture and the bump maps.

[arakish]

Don't know if this will help any. It is basically a height field I made of a single mountain peak. I converted it into a greyscale PNG. It might be able to be used for a volcano. It is 1024 x 1024 pixels, so you might have to shrink it some.

rmfr

[RecklessEnthusiasm]

Can you offer any hints on how to get a nice tall volcano? I have the following but I'm not quite sure what to change to ensure that I get one tall peak in the middle. I thought it was the ridges, but that didn't seem to do it.

It is always tricky to try and achieve a height effect on these kinds of things. I, like most people, resorted to a bevel effect in my July Challenge Entry along with a fake depth-of-field blur. Steel General did a really good job on this one, too.

[kjdavies]

I looked into it and experimented a bit more. You're kind of hampered here by the size of the area you're filling. It's going to have a relative shallow slope. I suspect that in order to get the bump map you're looking for you're going to have to crank it up high enough that you'll see some wicked artifacting.

[kjdavies]

I looked into it and experimented a bit more. You're kind of hampered here by the size of the area you're filling. It's going to have a relative shallow slope. I suspect that in order to get the bump map you're looking for you're going to have to crank it up high enough that you'll see some wicked artifacting.

I'm not sure if neilkal is still around (only the one post, it seems), but I realized a while ago he could probably achieve his goal by shrinking his heightmap (to, say, a quarter the resolution each way), generating a first bump map from that, then scaling that back up. He'll probably need to do a bit of smoothing and probably add another, mild, bump map to hide the artifacts (and for some reason I'm thinking a wee bit of displacement might be helpful), but it should come close.

The problem he ran into in the first place was that the gradient is 'very shallow' because of the size of the region it's applied in. Shrinking the image reduces the region the gradient is in and makes it seem steeper, and when he goes back to larger size that steepness should be carried back. Simply generating the heightmap and scaling that back up won't help, you have to create the bump map and manipulate that.

[lokiie1984]

This is a pretty awesome tutorial. I had a small issue with it last night on step 22 but i might have just missed a step (i needed to invert the layer for the gradient to work.) Now i just have to figure out the best shape to draw mountains. My first attempt was much to wide and they ended up looking like a giant candy bar lol

Thanks for posting it

[kjdavies]

I'm glad you liked it, lokiie1984. I'm curious about what you came up with, care to post some images?

I've refined the process a little and am still exploring a bit, and have been wanting to revise the tutorial for a while.

[zukeprime]

After the part where you put in the shaped angular blend, I just cut a hole out of the center with a 5-10px feather, then added extra highlight on a new layer. Merged the two, then continued with the rest of the tutorial.



Quick question though...I've found emboss really makes the mountains pop and takes less steps to accomplish. For example, the volcano above is just using emboss. Is there something I'm missing with not using height maps, etc?

[kjdavies]

After the part where you put in the shaped angular blend, I just cut a hole out of the center with a 5-10px feather, then added extra highlight on a new layer. Merged the two, then continued with the rest of the tutorial.



Quick question though...I've found emboss really makes the mountains pop and takes less steps to accomplish. For example, the volcano above is just using emboss. Is there something I'm missing with not using height maps, etc?

I'm not sure how I feel about such a perfectly cylindrical crater there, but I have to say I really like how the rest turned out.

As for bump mapping rather than embossing, I started with bump mapping and can't say I ever considered trying embossing. I just did a couple of quick experiments and didn't get anything really conclusive about applying one rather than the other, but I'll look into it in more depth when I have some more time (eating a quick lunch before I continue packing -- moving house Tuesday). You should go with what you like.

I do like how that turned out. Basically four ridges intersecting (roughly) at the peak and merged?