Did you know?

[dandelO]

Here's something I've just found that I don't think I've seen documented or in any changelogs.

When you make a rock object, you can give it smooth normals, loads of faces and use it a sphere object that can be ray trace rendered, and populated, unlike the default sphere, which can't to either. That's not the new thing I've found, I often do this.

What is interesting is the little input node on top of a rock object. The surface shaders are all inside, as is their input node, at default.
But this other little input that is visible on the rock node is called 'Mesh Displacer'!
So, rock objects can use RTO, with real mesh displacement, AND bump mapping for shading! Obviously, since it's actual 'mesh' displacement, the more faces your rock has, the better, so the mesh displacer has lots of points to work on.

Did you know that? I didn't!

Here's two preview render shots:

Default:
[attachimg=#]

With Fractal:
[attachimg=#]

I'm chuffed to bits with that, great!
Why have I never seen this before, I usually read all the changelogs thoroughly, and several times.
Also, there's no options in the settings panel for a rock object to assign a mesh displacer. I wonder why it's never been drawn attention to before? I'm sure I've never even heard mention of this feature.

I'm usually wrong, mind you!

[dandelO]

There are also some other very interesting things in the rock object file, I've made them bold here;

<rock
      name = "Rock 01"
      gui_use_node_pos = "1"
      gui_node_pos = "-920 -100 0"
      gui_group = "3. Objects"
      enable = "1"
      population_mode = "0"
      preview_options_main_hidden = "0"
      preview_options_main_bounding_box = "0"
      preview_options_main_wireframe = "1"
      preview_options_wf_bounding_box = "0"
      show_b-box_in_preview = "1"
      show_wireframe = "1"
      visible_to_camera = "1"
      visible_to_other_rays = "1"
      cast_shadows = "1"
      double-sided_surface = "0"
      use_smooth_normals = "1"
      flip_normals = "1"
      unique_variations = "1"
      seed = "45492"
      number_of_faces = "750"
      diameter = "1"
      shatter = "0"
      shatter_probability = "1"
      number_of_shatter_planes = "1"
      shatter_separation = "0.1"
      subdivide_mesh = "0"
      subdivision_level = "3"
      mesh_displacer = "Power fractal shader v3 01"
      translate = "0 0.5023327077 0"
      rotate = "0 0 0"
      scale = "1 1 1"
      import_motion_filename = ""
      heading = "0"
      elevation = "0"
      distance = "1"
      surface_shader = "Default shader 01"
      displacement_tolerance = "1"
      ></rock>

[choronr]

This looks exciting Martin; like I can see these rocks as asteroids is space; also, some neat looking rocks in the desert. Thank you for bringing this to our attention.

[Artistico]

I find it fascinating that one can discover something new in Terragen every day. It's like a continuous journey of discovery that rivals those of Dr. Livingstone and Charles Darwin.

And, obviously, rocks rock! 

[Splus12]

Wow!!  If it wasn't for people like you digging around we wouldn't know hardly anything about this program.  Thanks for finding this.

[Kevin F]

Something weird going on here though! If you make changes to the PF input to the rock no changes are applies to the rock. You can even disable the PF and the original changes stay. You have to disconnect the PF and let the rock return to a sphere  then reconnect the changed PF to make the changes apply.

[dandelO]

Yes, Kevin, I noticed that too. The wireframe doesn't refresh until you unplug/replug the mesh displacer. A pain in the neck if the rock has a couple of thousand faces and needs reloading on each replug.
Pretty cool little feature, though.

I remember when rocks used to just shatter when any type of displacement was added, now I can see how to make that happen again(if it was required for any reason) and also some interesting subdivision settings that don't seem related to 'number of faces'.
Very cool, something to play around with.

[Henry Blewer]

This is really cool. I just tried it out. I could not quite get extreme displacements, but this would work for pebbles, for instance, very well.

[Dune]

Cool find, Martin. Now we can make procedural mushrooms!

[FrankB]

Did I know? Yes
In fact I've been experimenting to update the Hero Rock object from the Fake Stone and Hero Rock pack V2.
It needs a little more work but I'll post a quick render in a few minutes. [EDIT: I will postpone this. there are some issues with displacement that I want to understand better first]

However the little bug that the populator doesn't realize when a displacement had changed probably prevents me from releasing it. Actually it's not only a problem when the displacement changes. The populator also doesn't seem to recognize changes in e.g. number of variations or faces. Always have to disconnect the object first, make a change, then reconnect, then repopulate.

Cheers,
Frank

[dandelO]

There's something in the changelog for 2.3.2.1 that says about the unique variations now being visible to the populator, or something, I'll hunt it down and post back here...

[dandelO]

From the most recent public version changelog...

If a population uses an object generator's Unique Variations feature (e.g. the Rock object), there was a bug that prevented changes to the object from being seen by the populator. This has been fixed. However, you still need to force a repopulation in order to get the changes.

Seems you not only need to repopulate, but also to replug any different mesh displacer nodes too.

[AP]

Tried this the other night. It gets very bogged down when using the rock object as a population with the displacement, even with a area of 10,000 meters. I will try 1,000 meters and see what happens. Nifty feature, none the less.

[inkydigit]

very interesting....I did not know this....thanks for hoking!

[Matt]

It's another experimental feature that needs a bit more tweaking before we officially release it (for example the updating of the preview and populations). It's accidental that the mesh displacer input is visible on the node

BTW, you don't need to have such a large number of faces if you enable mesh subdivision. A lower number of faces (e.g. the default 20) allows you to produce more faceted rocks which, when subdivided and displaced, might look more realistic.

Matt