Multi sheeted 1 prim Sculpt

[Tazmania Trefusis]

I'm messing with multi sheet/planed sculpts within Maya starting with a polygon plane and then folding and bending it to create multiple sheets very closely placed to eachother in a linear fashion

I like to experiment with Sculptures and arty builds, especially if theres an illusion of some sort in the build. I'm trying to achieve a graduated shadow effect on a single sculpt prim using a graduated alpha to black texture (made in Xara)  and the results are a little primitive. Eventually I want to put defined graphics on the sculpt so it falls on all the 'sheets' where I want it to within the sculpt. Defined graphics as in texures like alpha half tone, pokadot, gridded line effects etc. The texture doesn't lie on the 'planes' too well but when you see these 1 prim grass sculpts, the textures always look defined and not distorted. I'm looking for the same technique but I dont want the sheets (or inner faces) to be randomly placed, like in the grass sculpts but instead in a dense linear line of sheets/faces.

Hope that make sense

Taz

P.S. Chosen, thankyou for the Maya Nurbs sphere to Cuboid tutorial, appreciate it

 

 

[Chosen Few]

I'd love to help, Taz, but I'm afraid I don't understand what it is you're describing.  You're using terms I don't quite follow.  What do you mean by "multiple sheets", for exmaple?  How are you defining the word, "sheet"?

[Tazmania Trefusis]

Hiya Chosen, apologies for my abstract jargon lol. It's kind of hard to describe so Ive included a screenshot.

If I did manage to get many layers within the Sculpt, the shadow effect will be soo much more convincing. Something is going to be popping out of this shadow so has too look convincing lol plus i have another project where I want to use something similar but for a sculpture piece.

 So even though the effect is a little better by using 2 of the sculpt prims slightly offset to eachother, I'm trying to achieve many more layers but still using just 1 prim.

One other thing.....

Just want to insert the Nurbs Cuboid Pic too see if if it looks ok? after your informative tutorial :-)

It's advised (and necessary) to use Nurbs for your sculpty shapes but polygon planes also work? The Polygon plane primitive exports great after it's been deformed via the Ncloth deformer  so Polygon plane is the only polygon primitive we can use to manipulate?

Thanks in advance and I hope my included 1st pic explains what I'm looking to do.

I'm also doing Maya tutorials as it all helps.

Taz

 

[Chosen Few]

Your NURBS cuboid looks perfect, from what I can tell.  To answer your question about polygon-based sculpties in Maya, you'll find some good tips in this thread.  It's workable, but it's kind of a pain.

 

As for your multi-sheet, I assume you're going for a volumetric fog type of effect?  If so, my first suggestion would that you make the short connecting faces fully transparent.  Only the large faces should be visible, if I understand the effect you're trying to acheive.

As for the gradation looking stepped, I doubt you'll be able to solve that problem without adding many more faces into the mix.  Right now, you've got what, eight faces to work with?  That's just eight transparency values, out of 256 possible.  If you had 256 faces in there, you could acheive the same smoothness of gradient you can acheive in an image.  If you had 128 faces, you'd get half the levels, which would still look quite smooth.  Even 64 would probably be OK.  I suspect that once you dip down to 32 or less, the stepping is going to become really noticeable, since you'll have to exclud seven out of every eight values.

You're further compounding the problem by the fact that your gradient is reflected, rather than one-directional.  That cuts the amount of actual values you can use in half.  Also, it's pretty hard to determine how exactly the alpha blending from the overlapping surfaces is going to affect the appearance.

Then you've got the problem of distance between the faces.  The further apart they are, the less convincing the effect will be.

There's not going to be a neat solution here.  Whatever you come up with is going to be a hack at best.  SL just isn't set up to do volumetrics (not counting the built-in underwater effect and distance fog effect).

 

Mind if I ask why you're so intent on doing this with sculpties?  You could do the whole thing MUCH more efficiently, easily, and flexibly with mesh.  I made this volumetric fog object just now, in all of three clicks in Maya, and uploaded it to SL for just L$11.  It's 256 quads, spaced 1 centimeter apart (with no connecting faces), combined into one mesh object. It has a land impact of 1, and a display cost of just 444.  That beats the hell out of a sculpty, in every measurable way.

The texture on it is just plain blank, with 90% transparency applied.  The effect is pretty convincing.  Notice you can barely make out the avatar's left leg, while the right leg, which has less planes in front of it, is far more visible. If I were to grade the transparency, the effect would theoretically be even more dramatic, but that's more work than I felt like doing right now.

Of course, the illusion only works from the direction the planes are facing.  If I swing the camera around to the side, or the back, the fog disappears.  To make it work from all angles, we'd need additioonal faces pointing in all directions (easy enough to do).

 

Whichever way you approach it, I wouldn't get too carried away with objects like this.  I shudder to think what's going on with alpha sorting and render passes in this thing.  Even though SL considers the display cost to be only 444, it has no real way of judging the impact of all that overlapping transparency.  On the island where I'm working as I'm writing this I get a pretty steady 35 FPS, but when this object is in view, that drops to 25.  Needless to say, that's quite a significant drain.

[Tazmania Trefusis]

Thankyou chosen for your swift response

Thats a great example!..would love to see same pic but edited and see where all the edges are.

How do they get so many more 'planes' to work with on the grass example? theres faces going in all directions!

Is it basically the same technique? my simple example and the grass example? and can I get to that stage if i stay on these lines?

If you can have a polygon plane that is 32x32, can you effectively have one that is 1x1024 ? (or even a nurbs plane)..just one long, 1 segment high plane to bend and to keep bending at the vertices?

Fair enough Ive used up alot of vertices just by having these short sides The connecting faces you mentioned) inbetween the planes but it was just an experiment. They would normally be poled. If I was trying the grass trick, I could use those short sides as additional planes thus doubling up. Sometimes I'm going to not want then linear like that but in a different configuration

But theres so many on the grass sculpt..the division is so more numerous than my example, even if i did use the sides (if that makes any sense). Could I set mine up in Maya in a better way? to give me more options as to the number of 'planes' (sheets/faces etc)

Whatever this ends up as Chosen, it will probably only be short term, say for an art build and not something that is intended for long term rezzing.

Thanks for the thread link

Taz

[Drongle McMahon]

The most oblong sculpt map you can use is 4 x 256 quads (8 x 512 pixels). I don't know whether vyou can make that in Maya. Also, note that the LOD transitions don't affect the 4 dimension but instead take every fourth vertex from the higher LODs. So if you wanted a sculp that stayed intact after the first LOD step, you would need to have faces that were 4x4 quads. That would be only 64 faces.

However, Chosen is right. Mesh would not only be easier to make, but would also give you hugely greater flexibility for the purposes you describe. No artificial limitations, UV map stacking for greater detail, eight textures per mesh*. Then when you want to animate the textures, you will find a whole lot more advantages with the mesh version.

*You could have problems applying the textures inworld if some faces are obscured. You can get around that by makling the lowest LOD have all the textures in accessible triangles. Then you can set renderVolumeLODFactor to 0, place the textures and switch back to a reasonable value.

[Tazmania Trefusis]

Thnx for the info

Still curious to how they do that on the '1 prim grass' example ?

[Chosen Few]

From your picture, here's how I'd guess the one-prim sculpty grass was made:

1.  Start with a 4x256 plane.

2.  Fold the plane over four times, so you have a square tube with 256 sections.

3.  Fold the tube 256 times, hapazardly, so you end up with a "spaghetti plate" of seemingly disjointed surfaces.  In reality, it's all just one "noodle", but it's bent in so many different directions, it appears at first glance to be many.

4.  The texturing is really easy.  Notice in your screenshot, each section is roughly the same width.  Therefore, for the horizontal, all you need to do is repeat the texture 256 times, which you can obviously do in-world.  For the vertical, you'd want four panels built into the texture itself.  Panel 1 is the grass against a transparent background.  Panels 2 and 4 are completely transparent.  Panel 3 is the same as panel 1, but flipped upside down.

[Tazmania Trefusis]

Thanks for enlightning me there.

Now back to Maya and see if I can get these Nurb cuboids to texture a bit better :-)

[Tazmania Trefusis]

Hey Chosen, just one query.

when you say "Fold the tube 256 times" after turning it into a square tube, you mean top view, so Im getting what looks like a upright ladder, with a row of vertical vertexes (or is it 'verti' lol) either side. I just then start from the bottom or top, select a horizontal row of vertices and just bend to basically any angle and so on and so on. I dont need to flatten the square tube first and then fold? but fold it as a square ended tube?

 

Thanks

[Tazmania Trefusis]

No worries,

I shall play around with and try different ways to bend it.

When it's a flat plane with a series of panels then it's easy to bend at the vertices but this is a square tube!

[Chosen Few]

Sorry for the slow reply, Taz.  In didn't notice your post from a couple days ago.

Viewed from above, you'd want each section to be proportioned roughly like this:

Here's a quick GIF animation, showing how a few of the most easily identifiable parts of the maze are folded:

After that fifth fold, it gets kind of hard to tell where it goes next.  I tried a few different starting points, and lost track after just three or four folds for most of them.  These five were the best I could do, without really spending serious time on it. 

In any case, that hopefully should be enough to give you an idea what's going on with the model.  Notice each section is more or less equal in proportion to the one in my first picture.  Some of them end up thinning out, since the artist did not take the time to ensure a perfect degree of miter at every corner.  (I suspect this particular artist probably didn't do too well on that picture frame assignment back in middle school wood shop.)  But the length is more or less the same on all of them, give or take a bit here and there.

The height will of course be dependent on how tall you want your grass to be.

[Tazmania Trefusis]

Thanks again Chosen!