Re: 3D transformation to create Nets of a Rectangular Based Pyramid -
lookang
245 Posts
Based on my memory, I tried to use the syntax [[Angle, x-axis,y-axis,z-axis]] to control the rotation in Ejss. To compound series of transformation, use the group icon where group is the first to transform. In this example, http://iwant2study.org/ospsg/index.php/interactive-resources/mathematics/measurement-and-geometry/geometry/2-3d-shapes/411-netsofsolidswee I did a lot of such transformations.
Re: Re: 3D transformation to create Nets of a Rectangular Based Pyramid -
mrg_psu
9 Posts
Thanks Lookang
I did manage to figure out some of what you said through experimentation and examples. In order to show a ball spinning about a tilted axis, I first rotate it about Z (easy orientation of the texture file I am using), then tilt it about the x axis by the complimentary angle of a specified altitude angle and a final "azimuth" rotation of the axis. The (converted to radians, complementary angle stuff done in background) looks like this: [[az_rad,0,0,1],[tilt_rad,1,0,0],[rotation,0,0,1]]
I was surprised to find the order the transformations are applied is right to left, but I'm guessing it's being interpreted as a stack of transformation instructions (last in, first out) rather than an ordered list.
So I'm at the point where my spinning beach ball looks pretty cool, and I'm ready to add the interesting physics (gravity, drag, buoyancy and magnus effect)!
follow the Pyramid as it unfolds into a flat plane. net 1 was successful completed.
