eonite opened this issue on Nov 03, 2009 · 302 posts
eonite posted Fri, 25 December 2009 at 10:13 AM
Thanks, Abraham and FrankT!
Abraham: Yes I think its good to go back to the tutorials sometimes, since the cloud layers of the CloudScapes set are built on those techniques. If questions do remain dont hesitate to ask.
Quote -
For example- I put 2 cloud layers each a ' front' at altitude 0 and 1km, both with height of 2km, so there should be an overlap, as seen in the top right image (overlaping grey bands). But when I render it, there is a gap between the layers(top left image). I understand that the various density function manipulations change the appearance of the layer, and some areas in the band will have no density. But it would be nice to be able to see it in the preview windows.
Well, the camera view shows the cloud layer thickness. Within this thickness layer the clouds are located. As long as you have a density falloff near the top and bottom "(Custom Cloud Layers Profile" or a function) there will probably be a gap between two cloud layers, even if you see overlapping layers in the camera views. If you want the layers to actually overlap you need to for example lower the altitude of the upper layer.
This is the way it is and it seem logic to me.
You can rely on the Camera Preview, not necessarily on the camera views.
Quote - (Enabling cloud preview is completely useless, terribly slow and misses out on large areas, like the whole of my blue cloud which is seen from the top doesnt show up at all)
Agree. I rarely use it.
Quote - The other thing I dont follow, is the units of many of the parameters and the position of the pivoting point. I tried for example to use the offset-rotate-scale metanode to rotate the cloud layer - I have difficulties understanding what it's doing and I think it's becuase I dont know where the pivote point is.
The "pivot point" is 0/0/0, unless you apply an offset by adding an "Offset" node ABOVE the "Rotation&Twist" node.
Quote - I also tried to change the 'amount' parameters which should define where the edge of the front is.
I changed the value in the x direction from 0 (top left) to -1.5 (bottom left) and -2.0 (bottom right).
(y value left unchanged). I find it hard to understand the changes. (and what sort of units are these numbers...).
It`s hard to generally say what those values represent.
What I can say is that, when you apply an offset by using the Offset-Rotate-Scale Metanode, a value of 1 represents roughly an offset of 250 meters.
Quote - I had other problems that mistified me - changing the scale of the cloud material(in the range of 0.5-2) moved the position of the front's edge...
This is because when you are scaling the cloud material you are also scaling the function. Setting the scale of the cloud material to 2 for instance will double the offset applied to the front.
Artpearl, I suggest you are making more tests by just using one layer and get a good feel for the placement of the clouds. A lot can be explored by using the examples in CloudControl.