Hi,

I 'm trying to create a view of earth from space, where natural changes between night and day can be seen. I have two spheres, which textures are night view(city lights) and day view (map). The problem is how to blend them together so that the transition edge between the day and night isn't sharp but smooth. One approach is to translate other sphere a bit off center and move it, but the quality ot the effect is poor.

The ideal case would be that there is a light(sun) that shines the GEM sphere object(earth) and the light side is seen textured as day and other side as night. I have not seen that alphablend could be used only on some part of a GEM object such as sphere.

Any ideas how to create this?

Hi,

I have been using PD for half a year, and I have been running into the same problem. How to design effective Nth order IIR filter? What I need is exactly like biquad~, but a lot higher order(like 30). Has some developer made an external suitable for this or is there an effective way to do Nth order IIR with existing patches?

Thanks for your advices!

@obiwannabe said:

No. here's a fundamenral limitation in the design that stops this. Because of the sample delay in any feedback route you can only really do finite impulse response filters in Pd. To do an IIR you will have to create an external in C. I would talk to Mathieu Bouchard on the pd-list if I were you.

This is what I have realized. I have tested that very uneffective IIR can be done by setting [block~ 1] and using one sample delays, but that is not what I'm looking for. I quess I'll have to make an external in C, if one does not exist yet....