Tips For Limiting The Number of Prims

Hey Folks,
Do any of you have any useful tips or resources for limiting the number of prims used in a build? I'm pretty new to building, but I'm getting to the point where I would like to start to streamline some of my designs. Any suggestions or resources would be really appriciated.

Good use of textures can do wonders for reducing prim count.

For a simple example, if I wanted an interior wall with a baseboard molding, a crown molding, and a painting on the wall, I could do a prim for each molding strip, one for the wall, 4 for the picture frame and one for the picture... Or I could make a good quality texture with apparent shadows built in, that would make a single prim appear to be the same detailed wall.

If I wanted to do a window that has 9 window panes in a 3x3 array, a primmy solution might take 4 to 5 prims for the window frame, 4 more for the dividers between each pane of glass, and 1 to 9 panes of glass. Or I could make a single texture that has all of that, with the glass transparent and the frame parts opaque.

I recently reduced the prim count in a home by 48 prims, just by simplifying the doors throughout the house. They were made of 4 prims each, and I used custom textures to reduce them to one prim each. You can hardly tell the difference in the house, but it's 48 prims less.

I did away with doors and stairs completely in my house. It's hovering 50m in the air, I don't think it matters that you enter through windows that are temporarily phantom. Including a teleport in the floors to go up and down also saves walking to the stairs and gives more internal space.

I also used hollowed 10x10 cubes to create the windows (it's glass on all sides). With 2 of those, and 6 flat prims to make the floors and ceiling, you get a 2 floor 20x10 house in 8 prims.

Definately agree with the texturing tip above.

Very cool Ceera, thanks so much. I really haven't thought about using textures to minimize the number of prims. I will have to start looking into more advanced texturing techniques.

I use ramps instead of primmy stairs.

I've also seen some stair textures that look pretty decent.

I also stay away from the RL fixtures (dining room table and chairs, kitchens, bathrooms) which are sorta useless in SL unless you're designing a RL home for a virtual tour

I'm going to narrow the focus of this topic a bit. I can really see the practicality of textures in things like homes, larger, or more detailed builds. But what about actually limiting the number of prims for the sturcture of the design? I guess i've been thinking about boolean type operations, where you can combine or subtract two different prims to create the desired single prim shape? This is certainly not intended to lessen the value of the use of textures, in fact I can realy see how textures would be incredibly useful and "prim saving".

SL does not support subtractions in any way, shape, or form, so Booleans are not possible. The system is entirely additive.

Even when you cut a prim, you're not actually subtracting anything from it. You're simply changing the value of the "cut" parameter, which is always present. It's analogous to changing the sweep angle on a prim in Maya or Max (since you know Booleans, I assume you know what I mean by "sweep angle". You're not actually removing anything; you're just changing the degree by which the shape revolves around its center point.

LL has been talking for a long time about implementing "negative prims", which could potentially mimic the functionality of Booleans. A negative prim protruding through a positive prim would appear to make a hole. From what I understand though, it requires a fairly fundamental rewrite of the existing architecture, so it's not a small task. Don't expect it any time soon.

Hm. I've learned so much about making the most of each prim from my months of building (both while wandering SL and while walking around RL looking for things to figure out how to build), that I really think I have a great grasp of how to most efficiently assemble the shapes I require. However, unless you have a specific request, I think the best I can do is explain what to explore and how to teach yourself. Oh and firstly, the Ivory Tower of Primitives is certainly a good place to start understanding how prims work, although personally, by the time I found it, I didn't need it anymore.

To answer your question, no we don't exactly have boolean operations in SL, but the Hollow and Cut options can often suffice, and various other settings like the Hole Size (when available) should also be relevant to the effort of mimicking such cutouts. Plus, while there aren't negative prims, there are see-through textures, and even some invisible prims (look for the 'invisi-prim' or something like that) that block off visibility of various prims behind themselves, although the latter can be a little too powerful.

Now when it comes to learning how best to build everything, a little explorative, imaginative toying in any "sandbox" can do a whole lot of good. Play around with all of your prim shaping options (Edit window -> More -> Object tab), and get to know exactly what they do. When low-prim is the concern, especially pay attention to the power of the combining the Hollow and Cut options (note that toroids - the three prims that loop around like a donut - have two different dimensions of cut to explore), but also don't forget your ability to twist (e.g. set both Twist Begin and End to 45, and stretch that), and to pre-stretch your toroids with the X and Y Hole Size settings. As you play with all of the settings, learn how different prims can often be used to create the same forms, and try to figure out which one is really best for each. Each prim has its limitations to understand, sometimes in max/min sizes, sometimes in texturing, sometimes even in how easy they are to edit.

Since the subject of stairs has been brought up, here's a simple challenge: find two different ways to make a pair of steps with a single prim. These can actually be pulled off with just the same concept regardless of whether the stairs go straight across or on an elliptical arc.

Thank you all for the help and advice. I can't wait to begin diving into some of the approaches that you have all mentioned.

*oo**oo**oo* I know! I know!
/me waves hand frantically in the air.

(I won't spoil the fun of learning it yourself though)

A

When you study the lessons at the Ivory Tower, pay special attention to what they teach about cut and hollowed prims. These can also save on prim count.

For example, how many prims does it take to make a simple peaked roof, with two roof planes and two triangular ends? Assume the longest dimension need not exceed 10 Meters.

The initial thought for most people is 4. What you visibly see. But three will suffice, if you use a cut and hollowed 10M cube for the two planes of the roof. And if the roof does not need to have eves that stick out past the gabled ends or past the walls, and if the ceiling inside will be flat with no access to the "Attic", then one prim will do, cut across the corners, and not hollowed.

One warning. If you point a camera at the inside face of a hollowed prim, the closest you can get to it is the far outer surface that the prim would have if solid. So for example, if you make a round tower using a hollowed cylander, stand inside it, and try to aim a camera at the wall, you'll be looking at the outer surface of the cylander! A friend tried to make a round hut that way, and had to hang flat prim "curtains" around the inside, so he didn't keep having his camera thrown out of the hut!