Better way? Triangular Pyramid

I've done some scripting and I've pretty much got that down, but I'm quite the newb at building.
I need to make a triangular pyramid which has a flat 2.25m wide, 1.25m tall isosceles triangle at the bottom, a 1.5m tall, 2.25m wide isosceles triangle standing upright on one (back) side, and the two other sides are identical to each other. Thats one thing, but I need only the two sides that are identical to each other; that is, the bottom and back need to disappear and the whole thing needs to be hollowed out.
So basically, the two parts that I need are the two that I don't have the dimensions of (if it was vertex-based, this would be a snap).
I only see two ways to do this- trial and failure, which would take a long time because there are multiple places I need to do this in different dimensions, or to calculate it, which would require some serious number crunching.

Is there a better way? Seems like I'm making too much work for the size of it...

The back side meets the base at right angles?

Are you trying to make this shape from a single prim, or will two do?

If two will do then it shouldn't be technically difficult, just requires a bit of geometry.

Back side meets base at a right angle, yes.
Two will do.
The problem when I use manual calculations is that in many cases the lengths or angles are decimals too long for SL to handle, and so there are openings.

I suggest you make the object out of a triangular pyramid prim (the one after the square pyramid prim) then slap on a transparent texture on the unused faces.

Transparent textures will also have to go to the inside surfaces since you'll be hollowing out the pyramid. To place textures inside, crack the pyramid open with "path cut", place the textures then close the path again (0.00 1.00) when you're done.

Use a prism with the following parameters:




The only drawback here is that prisms don't hollow very well. The walls will be thick. If you need thinner walls, simply build the prism first, and then replace each side with thin tapered cubes. Use the prism as a template, and build the cubes right on top of it. No measurement required, and you should be able to make it seamless pretty easily.

Some other 'minor' drawbacks include, the pyramid isn't the correct size, and the back of the prim isn't really perpendicular.

To commemorate the 6-6-06 day use this.

Use a prism.

Size X: 1.666, Y:2.598, Z:1.5
Top shear X: -.25 Y:0

To build it out of 2 prisms so that you can hollow it, use the same prism above, then cut it

Cut B: 0.666, E: 1.0 for one side
Cut B: 0.0 E: 0.33 for the other

Then place them back to back.

However, if the height, width and length needs to be constantly changed, then you're out of luck. You have to bring out the calculator.

I can always count on you to delight in my mistakes, Cottonteil. I didn't realize the bounding box on a prism is larger than the prism itself. It never occurred to me to notice. Shows how often I use prisms, I guess.

Oh, and that 1.125 number I had was a typo for 1.5. Sorry about that, Bright. Too many 1's, 2's, and 5's in the whole thing. My fingers got the better of me there. Cottoneteil's right about the other numbers though, so use hers, not mine.

It's more of an irritation than a delight, but nevermind.

If it's so irritating for you, I cordially invite you not to read my posts.

I find delight in being irritated. So I will continue reading your maleducating posts as I don't believe in self censorship.

Hm, some problems with this. First of all, you forgot the xy taper=1 to make it into a pyramid, but I saw that easily enough. The main problem is that even with those cuts, and making the hollow 95 (max)(also something you didn't mention), it is still too thick for what I need. Is there any way to just use the solid prism and make certain sides fully transparent? Perhaps use a fully transparent texture on those faces?

EDIT:: The transparency thing works; the only thing is that you cant see the two faces from the inside, just from the outside; That's fine though; its a cockpit of a ship, so lets just say its made out of an opaque camera material and the camera shows on the inside =)

Prisms are by default tapered to 1 and I did mention that you should hollow it.

If you'd like both sides to be useable, you can always resort to cut pieces of a box to form triangles. They can be made into any form of triangle that is required.

Sometimes, even large spheres that are cut and dimpled can be formed into curved triangular pieces. The added bonus is that they can look nicer with shiny on.