Skydome

ok well… i have an interesting problem… I remember a simmilar problem a few versions back, i dont remember how i fixed it(maybe i didnt) but i am trying to parent a lamp to an object( a hemisphere) so that i can get a global illiumination sorta effect… now problem is, the old way(2.32? thats the last time i used it) isnt working… here is a screenshot of what its supposed to look like http://download.blender.org/documentation/html/gfx/chapter_lighting/GIScheme5.png

looks good, i wish i could get that back again… grrr…
here is what i have:
http://img48.exs.cx/img48/3676/problem.png
as you can see the sides are skewed its like there is a plane bisecting the hemisphere at a 45`angle that is somehow constraining the rotation of the lamps… all i did was a simple parent, and a dupliVerts, and a rot on the hemisphere… anyone have the same problem/know how to fix it?

You could point the spots towards the center using an empty.
Just add an empty in the middle and add an track-to contraint to the lamp.

Personally, I don’t like this way of lightning at all. Try using radiosity rendering (not vertex lights) and shadow-only lamps. Or even better: use Yafray if you don’t need particle generators.

well the only reason i like this sorta lighting is that it gives me a lot of control over where the light goes, sure radiosity is good, but for what i need i dont really want that… The problem is i dont have a specific light source(its in space) Ive tried the empty method, and it just makes things go crazy, something is completely out of whack… very wierd…

ok well i just deleted everything and tried again… and now it works without a hitch… i’m baffled… all i can say is wtf? does anyone know why this woulc/could happen???

All I know is that you have to do all your parwenting and dupliverting in top view, (Num Pad 7), for some weird reason.

Don’t ask me why that is, but it is the only way it works.

I used to use this setup a lot. Gives very good results. Should get back to using it sometime.

BgDM

i think i just figured that out. thats very strange that it only works in topview… very very strange. but oh well it works now.

any chance of posting a basic .blend of the setup for others of us to use for scenes? it’d be a timesaver for those situations that it’d work well for. TIA.

The reason it works in top view is that the new object’s axis and world axis are aligned to the same orientation if the object is added in top view. BEFORE parenting/tracking ALWAYS do a ctrl-a (apply size and rotation) which sets the object axis to be the same as the global axis. The video on dupliverts at http://www.ibiblio.org/bvidtute explains all this and more. I don’t know why this is needed in blender (it isn’t in other apps I have used). It is almost as if one matrix multiplication/transformation to covert local to global axis has been left out.

GreyBeard.