Terraforming Caves

[Cerebrogasm]

Hi all:

I rent a homestead 256m x 256m (standard) and I'd like to install a network of mostly hidden caves and chambers in mountains and even from above to below sea level. I have the Fantik Cave system and a few other assembled cave models. However, I can't "insert" them in any seafloor raised island - I'm guessing there's an inpenetrable and invisible shape beneath the homestead's 4 elevation-sensitive texture maps. I also believe I can't "cut" a hole in the island-mountain to create an entrance. 

One designer told me to create a "U" shape island and seat the cave structure at the bottom of the U while surrounding the  open, visible area with environmental props like trees and boulders. 

However, I was on a sim where there was an extensive cave system - that extended beneath the sea-level. When my avatar descends the stairs of that cave (which begins far above sea level), he does not intercept the sea plane - it's a very realistic effect. Also, camping below the water level, I can see the entire cave structure is seated within a molded (and textured) polygonal mesh - where are such meshes found?

it appears as if we can't use the SL homestead sub-bottom mesh (which respond to the Raise command in the Build menu) to insert openings or contain structures like the caves. 

I may have this all wrong - it's what I have observed - any advice on how to accomplish this (caves in mountains and even the sub-sea level caves) - greatly appreciated! 

Thanks!

James (Cerebrogasm)

 

[Lindal Kidd]

You can't dig a tunnel or hollow out a cave in Second Life land, because land is a one-sided surface.  What you CAN do is dig a hole.  It can even be a BIG hole.  The hole is then roofed over with stones, or other textured prims, to create the cave.  Or you can build a mountain entirely out of prims, with a hollow center.

It's harder to hide the fact that you're going under water, unless your cave is ENTIRELY below sea level...but it can be done, with the right water settings in the Environment editor, and clever lighting.

[Love Zhaoying]

7 minutes ago, Lindal Kidd said:

You can't dig a tunnel or hollow out a cave in Second Life land, because land is a one-sided surface.  What you CAN do is dig a hole.  It can even be a BIG hole.  The hole is then roofed over with stones, or other textured prims, to create the cave.  Or you can build a mountain entirely out of prims, with a hollow center.

It's harder to hide the fact that you're going under water, unless your cave is ENTIRELY below sea level...but it can be done, with the right water settings in the Environment editor, and clever lighting.

If the terrain is rocky, and you dig a hole, rez everything upside-down and sit/cam upside-down, won’t that look like a cave?

[Lindal Kidd]

Just now, Love Zhaoying said:

If the terrain is rocky, and you dig a hole, rez everything upside-down and sit/cam upside-down, won’t that look like a cave?

Well, yeah.  But if you stand up you fall up and crash onto the ceiling headfirst.  Then you need some Excedrin.

Back to (sort of) the subject of caves.  I have seen some terrific caves and unusual houses in SL.  Here are some I remember:

Midnight Reflections.  An entire sim built as a cave.  Glowy cave flowers, phosphorescent moss, cuddle spots, underground streams and lakes.  Gone now, sad to say.

Greenies.  This giant cave had an entrance tunnel that opened up into an enormous house.  Everything was built to giant scale...there was a cat the size of a dragon.  The place was peopled with dissipated looking green aliens with beer bellies who were in poses showing they were in the process of trashing the place while the owner was away.  Also long gone.

An undersea home dug into the seabed and camouflaged with a prim over it that was the same texture as the sea floor.

A home dungeon that was accessed by a camouflaged trap door.  My first look at some of the more esoteric, um...machinery for BDSM.

An "underground" dungeon hidden inside a rocky skybox island.  Accessed by jumping into the pond, and walking through a phantom rock wall.  (This one was my own creation).

An undersea wreck...a cabin cruiser set at an angle into the seabed.  Inside, the floors were built level and it was a comfy little apartment.

A huge hidden cave in the Chakryn Forest fantasy sim.  Accessed by wandering around up on the highest mountaintops, until you fall through.

A tunnel system that was so twisty it was darn hard to find your way out of.  I wound up getting frustrated and teleporting home.

[Love Zhaoying]

I bought some nice caves on SL.

[Lindal Kidd]

8 minutes ago, Love Zhaoying said:

I bought some nice caves on SL.

Did you ever bake a lair cave?

[Chic Aeon]

You can make a whole cave system including landforms to go "above ground" in mesh. A pretty extensive project though.

When invisaprims were still a thing there was apparently a way to keep the water out (I was in an event once that had an underground subway at ground level and it was impressive. That was long ago however and from what I have read (haven't tried) the effect only worked under certain viewer conditions. 

[Rolig Loon]

2 minutes ago, Chic Aeon said:

You can make a whole cave system including landforms to go "above ground" in mesh. A pretty extensive project though.

Like the mines in Horizons.  That whole set of tunnels and caverns is above ground in a mesh superstructure.

It's also possible to take your mesh cave structure into the sky and enter it by teleport through a "door".  That has some advantages like doing away with the need for terraforming the outside of the cave, and it can result in lower lag than if the same structure were placed at ground level.

[Love Zhaoying]

56 minutes ago, Lindal Kidd said:

Did you ever bake a lair cave?

No.

[Rolig Loon]

1 hour ago, Lindal Kidd said:

Did you ever bake a lair cave?

My foggy brain read that as "layer cake."   Time to go to bed.

[Cerebrogasm]

How about this: if I built a polygonal square mesh surface, in external software such as Blender, and create a "hole" in this mesh (a boolean subtraction that results in what appears to be a hole but is really the software clipping with joining lines at the vertices where they meet an "inserted cylinder"). Normals would be added later to each polygon for texturing. 

Can I then import that square mesh with an apparent hole in it, into SL? If that's possible, would SL "see" the apparent hole and allow an avatar, for example, to walk through? The mesh surface could then be rotated to for a kind of open door to the cave structures  purchased. Seams cold be masked by texturing. 

Is this similar to what a professional builder does to create doors, except by using rectangular intersection objects?

I guess my question could be refined to - what are "best practices" in SL to create caves that didn't require a lot of time and expense to compensate CG tricks needed due to lack of certain tools I'm used to in other software?

Thanks for your thoughts - and taking the time to write - I'll try anything that sounds feasible for me at my current understanding of SL building.

James 

[Rolig Loon]

42 minutes ago, Cerebrogasm said:

Can I then import that square mesh with an apparent hole in it, into SL? If that's possible, would SL "see" the apparent hole and allow an avatar, for example, to walk through? The mesh surface could then be rotated to for a kind of open door to the cave structures  purchased. Seams cold be masked by texturing. 

As in this small "cave" that I built for a friend a few years ago?

The mesh is a lid over a pit in the ground, and it has a hole, as you describe, that can be closed with a pair of sliding doors that are normally concealed in the lid. It's very easy to walk in and out.  This one is quite simple -- basically a one-room hideaway, all that I could manage when I was just learning to make mesh objects -- but it works rather nicely.

[ChinRey]

7 hours ago, Cerebrogasm said:

However, I was on a sim where there was an extensive cave system - that extended beneath the sea-level. When my avatar descends the stairs of that cave (which begins far above sea level), he does not intercept the sea plane - it's a very realistic effect.

Others have answered you main question: Caves in SL are essentially a strange looking houses: prim and/or sculpt and/or mesh structurer you can walk inside. They come in all shapes and sizes and are actually quite common.

The hidden water surface is done with an invisiprim, a prim with a special alpha texture that makes some visual elements (includign the water surface) invisible. I'm not sure if invisiprims were ever officially supported though and they are partly borken by now since they don't work with ALM.

[Cerebrogasm]

Thank you Rolig and ChinRey (and of course everyone else above that contributed to this answer).

Rolig: I am not sure how you actually created the hole in your photos. Did you use the external Blender mesh idea I proposed or was this done with current SL tools? Can you describe how you achieved this effect?

ChinRey: I'm confused by your last statement regarding "invisiprims;" are they still an option available in SL construction in it's current (2018) release? 

Thanks!

James

[Rolig Loon]

6 hours ago, Cerebrogasm said:

Rolig: I am not sure how you actually created the hole in your photos. Did you use the external Blender mesh idea I proposed or was this done with current SL tools? Can you describe how you achieved this effect?

Very easy. All mesh it made externally and uploaded. That "lid" is a two-sided curved surface with a hole, made in Blender. It's no harder than making any other opening for a door or a window. Now, in fact, the rest of that "cave" is a little more complicated than I suggested because I also made a mesh liner for the insides -- like the cave system that you bought. That's the textured blue surface you can see in the photo.  Still, that's no more difficult than making a big bowl and dropping it in the hole in the ground.

6 hours ago, Cerebrogasm said:

ChinRey: I'm confused by your last statement regarding "invisiprims;" are they still an option available in SL construction in it's current (2018) release? 

Invisiprims were always "unofficial" but tolerated because they filled a real need. When LL changed the way of handling alpha in 2012(?), though, they were no longer necessary.  AND invisiprims no longer work if you have ALM turned on -- as most people do these days.  You're welcome to use them, but most people won't see them.

[Cerebrogasm]

Thank you all for your answers.

I managed to create a reasonable cave system above the water line and within a floating mesh island on my sim. I realized that SL objects are one sided - I believe this is due to the ordering of vertexes to generate surface normals. To address this, instead of learning Blender (which I intend to do eventually), I basically "married" sculpted and textured mesh cave surfaces to each other, facing opposite directions, thereby giving each side of a mesh a surface normal and texture. I realize this is not a perfect solution. As far as entry into the cave system within the exterior island, I used an artistic teleport - an archway the user clicks on and will be transported to the cave entry. 

Of course I would prefer to have the cave system truly below the water line, with some form of walkway entry, which bars the water line from visibility as the user's avatar descends downward into the cave system. I don't believe this is possible - if it is - please drop me a line and I'll re-think the placement of the caves.

Much appreciated!

James

[Rolig Loon]

Congratulations!  It does sound like a fun project.  Making both an inside and an outside has doubled the number of verts in your setup, and therefore its L.I.  You might be able to save some L.I. by linking one of them (the outside one, I would guess) to a cube prim and then changing its physics type to NONE.  Ideally, of course, you'd want to delete all of the verts that will never be seen, sol you save more download cost there too.