Landscape tutorials for Houdini ?

[starkhorn]

Folks,

I'm trying to learn how to do landscape modelling (so far I've only been trying to do stuff like lamps or pool tables etc, so this is quite a major leap for me).

I got a picture out from my hols which is of the sea, beach, cliffs with mountains in the distance..........you get the idea.

Anyway, I was wondering if there were any landscape tutorials 9ideally using houdini) on the best way to go about doing landscapes. Are there any about ?

The only one that I was able to find was the rocket tutorial from the 5.5 tutorial guide but I'm was looking for something showing a more detailed landscape rather than just a few craters.

I'm currently playing with Fractals and VEX Mountains but I was wondering if there were any tutorials already done as to be honest I'm struggling.

Many thanks in advance.

Cheers

Starkhorn

[Marc]

Hey Starkhorn

I would say that modeling a generic landscape and trying to recreate one from a photograph would be two totally seperate approaches.

The generic landscape is obviously much easier. A few fractals, and a sculpt SOP later and you can get it looking pretty good.

if you're trying to recreate something then I would take a more traditional modeling approach. Put a grid down where you want your beach to be and shape it with sculpt and edit SOPs. Perhaps put a box in the position where the cliffs and hills would be, give it some divisions and then sculpt/edit/polyplsit the heck out of it until it looks similar to the picture.

I don't think there's an easy (ie quick) solution to this.

[Marc]

Actually...

After I'd actually thought about it for a few more seconds I came up with another solution you may want to try.

Put the picture in the background and trace the edge of the cliff/hills etc. with a curve SOP. Now you have the profile of your landscape. You can then draw a bunch of cross-section curves perpindicular to the original curve making sure that the center point matches in height with your original. After you've done this you can skin the cross sections and will have something that vaguely resembles the shape. Then you'll need to edit/sculpt and probably subdivide it until it fits better.

The benefit of doing the curve->skin method is that you can go back to the original curves and just pull them around until your skinned object looks more like the picture.

I hope this makes sense, I haven't finished my first coffee yet....

...er.. I can post a file if you want one.

Ciao

Marc

[michael]

this is an interesting question...

I tried to think of examples of landscapes done in Houdini but all the ones I could think of were things like the Time Machine stuff that DD did - but that was terragen, USGA data etc....(the USGA stuff is the best way to go IMHO)

[TheDunadan]

Here a few tips/ideas of mine on landscape creation:

The quick and dirty way to get a more or less decent landscape is grabbing a heightmap from a program such as terragen. With VEX it is pretty easy displace your inital grid using such images (see lava tut on sidefx.com). But this won't be of much help, if you have something specific in mind.

No matter if you took the rough geometry from a heightfield map or have done something similar to what Marc suggested and you'll have rather rough version of your landscape and it's time for the details part. A few things you should always keep in mind. If there are some mountains in the distance, make it a seperate object. Try seperating your landscape in "logical" parts since the amount of detail required, shader settings will likely differ quite a bit and having seperate objects makes life much much easier. Possibly you'll have as well different light sets... If you want some animation make a "previz" version of the landscape and try finalising the camera animation. Doing so you can decide where you need detail, where you might get away with textured planes etc. Don't even think about making a landscape / terrain with the same degree of detail everywhere.

Unless you have some interaction with the geometry, if you want extra detail consider doing it with shaders / displacement shaders. Fractals can add some very nice detail and besides often there are quite a few dependies between shading and geometry. The main advantage is, landscapes tend do have lots of detail and doing all with polys will make rendering etc. pretty slow, but using subpixel displacement the extra polys for the details are generated dynamically at rendertime and only where needed. The book "Texturing and Modelling: A procedural approach" has quite a few sample renderman shader codes and it's not very difficult to transfer these to mantra compatible shaders. If you don't enjoy shader writing, you can get pretty far with the existing VOPs though.

Have fun and post your progress

Jens

[starkhorn]

Thanks guys for the responses. Really useful and I'll try those out and let you know how I get on....my biggest problem was looking at the photo and trying to figure out where to start or what with.

I was trying to figure out whether a grid or box would be best but I think a grid looks best from your comments and from my initial experiments with sculpt, Vex mountain etc

Nice idea about putting the photo in background and using a curve....I should have thought of that as I've watched the stud shoe tutorial from the vislab tutorial.

Thanks Marc for your offering of doing a file but I'd like to try to figure this one out for myself.....I'd hate to come across as someone who just posts questions and gets more experienced patrons to do all the work.

Although if I'm desperate then I'll let you know.....

Thanks again, much appreciated.

Cheers

Starkhorn

[Keyframe]

Hey Starkhorn,

Another thing to consider would be to match the lensing from the photograph, to your CG cam. While the changes are subtle, once you get into an extremely deep shot (such as a landscape - which are often shot with a long focal length), you will notice that perspective will start to impose it's nasty head on your model.

Matching the lenses will hopefully help minimize the impact of projection on your model.

Another often-occuring mishap is using photographic reference when modelling via the orthgraphic view (i'm thinking of having to model a particular face, as opposed to a generic face for example). Remember, the photograph was NOT taken via an orthgraphic camera (There is not such thing in fact, outside the CG world - though large format cameras can help reduce that distortion to a certain degree). It can be helpfull to setup dummy Left/Front camera (with matching focal lengths of course) so that you are putting down your construction curves along a more approporiate projection.

Hope this helps shed some light on the matter.

Cheers,

Gene

[digitallysane]

This tutorial might be useful:

http://oldsite.vislab.usyd.edu.au/staff/be...aust/index.html

Dragos

[starkhorn]

Thanks folks for your help. Just letting you know that yes I'm still working on it (and finding the going slow due to lack of time and also expertise on my part).

Will post what I've done at a later date....once I think that I've gotten something worth showing....

Thanks though for the replies/advice and that tutorial link for doing the landscape map of australia.

Cheers

Starkhorn

[stu]

this is an interesting question...

I tried to think of examples of landscapes done in Houdini but all the ones I could think of were things like the Time Machine stuff that DD did - but that was terragen, USGA data etc....(the USGA stuff is the best way to go IMHO)

12521[/snapback]

I did some terrain modelling for an "X" movie with some "Men" in it a while back - I used the old model SOP (it's kinda like complaining about having to walk in 5 feet of snow uphill both ways to school).

Poor, poor, model SOP, struck down in it's prime. Where are you when I need you most?

(sniff)

stu

[Marc]

Poor, poor, model SOP, struck down in it's prime. Where are you when I need you most?

13692[/snapback]

I like to liken the model SOP to an old, incontinent hunting dog. It once looked pretty and certainly had its uses, but now just lies around and stinks up the place (now being then, of course).

What I used to model in two months I can do in two days now with the new one.

But hey, whatever floats your boat .

Marc

P.S. Does anyone think that the winking guy looks like he's got something caught in his eye? Or maybe some sort of twitch? crazy I tell ya.