Andreas nous illumina en ce 2008-07-06 08:46 -->
> Hi!
> 
> I'm relatively new to POV-Ray, and I have some questions regarding a small
> project I'm working on.
> 
> For one thing, I'd like to create a lava flow of sorts, which would illuminate
> the surrounding area. I've tried to make the flow hollow and use it as a light
> source, but that didn't seem to work. So I made a flow with high ambiance
> levels, and used radiosity, which would light up the the canal in which the
> lava flows. However, this does not light up any objects further away. Any
> suggestions on this matter?

"hollow" enable an object to contain some media, it don't have any other function.
You can make the lava transparent, or add "no_shadow", and put some light_source 
inside of it.
Your idea of using radiosity is the more realist way of doing it. If it don't 
light up farther objects, it can be because:
  - there is some obstacle between the "lava" ant that object. (very probable) 
If the lava is inside a trench, it will only light the trench and things that 
are over it.
  - the object is to far away for the "light" coming from the lava to have a 
significant offect. Give the lava a very high ambient value to thest that, like 
ambient 100000. ANYTHING that is still dark don't have a line of sight to the lava.
  - you may not have enough radiosity ray traced and you miss the lava. Try 
increasing the count value, it can go as high as 1600, to something like 200 to 500.
If the scene is inside something like a cave or tunel, you may need to increase 
recursion_limit to 4, 5, or maybe some more. Don't overdo that, there is a point 
of reduced return.

Do you have some fumes that you'd like to be lighted by the lava? In that case, 
you need to have actual lights as radiosity don't shine on media.

> 
> The second question is about texturing. I'd like to make a whip (bullwhip to be
> exact..), but I can't seem to get the texture (braids) to follow the surface.
> So far I've tried sphere_sweep and a 3D model which I've made, but nothing
> seems to work correctly.
> On the topic of texturing, I've thought about using two layered textures rotated
> to be perpendicular to each other to simulate the braids, but does anyone have a
> better approach?
> 
> Thank you for any tips and tricks you can share
> 
> 
> Andreas
> 
> 
You can go the hard way of using 3 sphere_sweep to actualy make your braid. You 
can then use a very plain texture as the aspect will be provided by the actual 
shape. In this case, I'd recomend using 3 slightly different textures, one for 
each strip.
If you use a modeler, you should turn on uv maping. Apply the texture to the 
straight whip, then make it bend and twist. That way, the texture should follow 
the shape.

-- 
Alain
-------------------------------------------------
Experience demands that man is the only animal which devours his own kind,
for I can apply no milder term to the general prey of the rich on the poor.
Thomas Jefferson

Post a reply to this message