[Papervision3D] Half Sphere - Primitives and Ideas

[Peter Kapelyan]

Hi all,

This message is for Ralph and Tim have some ideas for you, and anyone else
that may think of something.

A few ideas ran through my mind and I wanted to let you know what I have
been thinking.

Instead of modelling objects in Lightwave(whatever) I wanted to make most of
my scene out of PV3D Primitives.
So as I was thinking of how to do a turtle, I realized I can do the shell
with a cone, or better yet half-sphere.
Feel like making a half sphere Tim? :) ........... :)

Now this One idea only works with a HALFSHPERE, but I have another idea
also.

I realized how a HALFSHPERE can be ultra cool.
When you look at a SPHERE, you never see the other side of it, unless the
material is transparent, and I am talking just one on screen camera for now.
So in reality, nobody really NEEDS the other side of the sphere for
anything!!!
If the texture can be scrolled across that HALFSPHERE and it is Pointed at
the camera...., instead rotating a regular SPHERE itself...., then
effectively would be exactly like rotating a SPHERE!!!!!!!!!!!!!!!!
THis is ultra cool - because half the polygons/information are needed!!!!

Ok now that I have calmed down (and figured out a way for some kind of
backface culling hopefully) here is my other idea.

If there are such things as "faces" to the primitives (for a box 6 sides...)
then can't you just delete a face?
This would be ultracool too because imagine a box with one face missing,
well, you have a paper bag, or you are looking into a room with one wall
missing.
Also Imagine a cone with the bottom missing upside down, you now have an
icecream cone.
Besides all the uses of removing some faces for making objects, I am sure
with some correct Z calculations the faces on the back can be deleted as
well if needed. This probably needs to be done on each object individually
depending on the material, because say you have the same object with a
transparent type material, and you NEED the back faces.

Tim, want to make HALFSPHERE :) I guess it's half a sphere - with the code
for your top/bottom in the middle. :)

Ralph, want to make material = cullbackface!!!!!!!! :) ?????????
or material ScrollHalfSphere :)

You would have to maybe only be able to delete a range of polygons in the
order they are created, or the final one, maybe make the parameters for
deleting faces in the order of creation ( a certain range like 1rst face to
5th face), or make it flexible enough for something like dependant on Z
order for backface culling unless its done with the material somehow.

Hope these crazy ideas make some sense as they could be of much use. Haven't
spent much time using PV3D - buying Flash CS3 left me broke so I have more
time to think :)

-Pete
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