Geometry libraries and 2 sided geometry

I’m a newbie and working my way thru vvvv basics by trying to convert some video pieces I’ve done in a product called Zuma ( One of the that packages nice features is some predefined geometries, similar to, but a bit richer than vvvv - sphere, torus, isohedrons, and a sea shell. A couple of questions:

  • Any libraries/modules supporting additional mathematically based models? The parameters exposed in Zuma are fairly rich. For example, I’ve been able to get some long ribbon effects via the Zuma cone model by manipulating the number of twists and angle of the spiral.

  • Most Zuma internal models have the ability to be rendered double sided, which allows for a scene to be built within a large sphere, which provides some interesting effects - for example, a moving starfield within a sphere model. The only “builtin” model in vvvv that I seem to be able to get “inside” is the Cone geometry. The vvvv Sphere in particular doesn’t seem double sided. (See the attached patch - incrementing the Scale pin on the Sphere model eventually hides the model from rendering.) Any hints on finding models that would support such a capability. Do DirectX models?


Chuck (80.4 kB)

The way to get weird shapes is to apply an ArbitaryPoint to an object, a grid is very suited for that. Need to hunt down some examples for you, but you will find it very powerfull and funny. I know Kalle made a great tutorial, and many of us used it for patches posted on the Wiki user pages.

In order to look INSIDE a model, you need LIGHT, the constant you used doesn’t support light. So all you see is black/darness.

I know my answers are a bit sumier, I am not that good in explaining 3D stuff, but I sure try! Happy Xmass :) (81.2 kB)

west is refering to User Tutorials

Many thanks. This example and the user tutorials on transform hierarchies and arbitrary points are indeed helping me get a handle on vvvv very quickly.

check the Cull (EX9.Renderstate) node for enabling Two-sided lighting. The default setting is that only one side of a polygon is visible. By disabling culling you will see both sides.

Apart from using the slightly arbitrary way of using ArbitraryTransform you should learn about VertexBuffer (Join) and Mesh (Join) to create your own geometry. Or import some geometry, split it, do some math and join it again.

And make sure to know @sanch|sanchs)) and ((user:tonfilm wonderful ways of doing math in a vertex shader

Carrying this discussion one step further - a widely used feature in my previous video program - Zuma - was the ability to vary the level of translucency for any rendered object (or mesh as the vvvv counterpart). The example above that West modified - - was very helpful. However, is there a general method for achieving variable translucency for the star sphere? Is it a product of certain shaders/effects?