i cant seem to make a straight up vertical comlumn of light in blender. A spot with a halo, but you cant make a straight column of light. it also doesnt help when the halo odesnt obey ray tracing.
It´s a long shot but did you try to let a directional light (not sure if Blender has those) project a ring-shaped map? It´s a quick&dirty solution but it usually works in Max.
Maybe use the same trick they used before Lightwave was able to render true orthographic views. Place the spotlight extremely far away and use a quite narrow cone. In the area you´re interested in the result should be reasonably close to a cylinder. Hoping here that Blender can control the start and stop distances of a spotlight emission you´d be set with the next best thing to a real directional light.
Yeah... The only way I can see to circumvent that would be to change the angle of the beam to about 15 degree and move the origin of the light out a bit so you don't have a starting point...
Yeah, I'm tired... If you need a translation I would be glad to lend it...
-albert
Right, well taking the cube for scale, its the default when you hit Add > Cube from the men (i.e. 1x1x1). You need to modify this stuff for your own preference, but the scene is essentially:
Spot light set z=500 units upwards with an arc of 1' and the SpotBI set to 1 so that the entire thing is soft-edge. Halo on, with the intensity set to between 1 and 2.5 (again depending on what you want).
The roof and square hole is just for effect, but in this case I've also got a second halo spot set to about 7.5' arc and a SpotBI set to .25 hidden just within the conduit so that it's origin is hidden. This one gives the internal shaft of light. You don't really need it, it was just for effect.
A third halo spot light is off camera to the bottom, facing upwards. This is not required for the shaft, it's just to give a general glow. It was about 45' arc, large SpotBI value and a reasonably low energy just so that it would wash a little of the scene - remembering that halos are additive.
This image was rendered with AO turned on just to intensify the effect a little. Both the shaft spots had a little yellow added to the colour, but you could set it to whatever is actually required for your scene.
The trick here is putting the spotlight way, way back. You can't get a solid shaft because lights simply don't work like that - in real-life or in CGI. Whenever you get a solid shaft on TV or Film, chances are that its quite a complex lighting rig with a lot of lamps, all at particular angles to form the walls of the shaft. I've done this quite a bit - while I didn't go for a pure vertical shaft, The Crate image had something like 60 lamps in it to give the halo misting effect. Just remember that more halo lamps you add, the lower you need to make the intensity of each - the additive effect will just make the whole scene go a solid colour if you dont reduce the individual effects.
What you can do however, it lower the arc angle to such a degree that it becomes vertical to the human eye. This is 1', but you could go lower by pushing the lamp further back and increasing the effective distance of the lamp (this one naturally has to go over 500 units to hit the cube).
Posts
-albert
Also, Dallidas, you could model a simple spot light and use that. As in, a mesh that directs the light.
-albert
well i want to be able to see the shaft. The halos dont seem to care about mesh boundries.
-albert
not quite..:cool:
Rendered in 2.4
See the image below for more information...
[edit]I'm sorry for taking so long to reply. I had to dig the stupid thing out the mire in my hard drive.[/edit]
-albert
it also does the same thing in version 2.37
also the halo doesnt show up at all when rendered in yafray
But I have a review to write first.
-albert
what review are you writing?
-albert
Pics are below, I hope this helps.
-albert
[edit]See the bottom of this page for the download. It is titled "A Volumetric Light Test Blend."[/edit]
Yeah, I'm tired... If you need a translation I would be glad to lend it...
-albert
Spot light set z=500 units upwards with an arc of 1' and the SpotBI set to 1 so that the entire thing is soft-edge. Halo on, with the intensity set to between 1 and 2.5 (again depending on what you want).
The roof and square hole is just for effect, but in this case I've also got a second halo spot set to about 7.5' arc and a SpotBI set to .25 hidden just within the conduit so that it's origin is hidden. This one gives the internal shaft of light. You don't really need it, it was just for effect.
A third halo spot light is off camera to the bottom, facing upwards. This is not required for the shaft, it's just to give a general glow. It was about 45' arc, large SpotBI value and a reasonably low energy just so that it would wash a little of the scene - remembering that halos are additive.
This image was rendered with AO turned on just to intensify the effect a little. Both the shaft spots had a little yellow added to the colour, but you could set it to whatever is actually required for your scene.
The trick here is putting the spotlight way, way back. You can't get a solid shaft because lights simply don't work like that - in real-life or in CGI. Whenever you get a solid shaft on TV or Film, chances are that its quite a complex lighting rig with a lot of lamps, all at particular angles to form the walls of the shaft. I've done this quite a bit - while I didn't go for a pure vertical shaft, The Crate image had something like 60 lamps in it to give the halo misting effect. Just remember that more halo lamps you add, the lower you need to make the intensity of each - the additive effect will just make the whole scene go a solid colour if you dont reduce the individual effects.
What you can do however, it lower the arc angle to such a degree that it becomes vertical to the human eye. This is 1', but you could go lower by pushing the lamp further back and increasing the effective distance of the lamp (this one naturally has to go over 500 units to hit the cube).