Making a light source visible

Support Lighting and Rendering
1

Hi. I’m very much a Blender n00b, but I was wondering what approaches there were for making a light source itself visible. For example, like if I was looking into the sun, or a really bright star, or the glory of God from heaven, or something else brilliant and radiant and glowing.

I was able to to achieve this effect with some degree of satisfaction by

  1. creating a sphere
  2. putting a lamp inside the sphere
  3. setting the sphere’s material color alpha to zero
  4. Activate the materials ZTransp render pipeline option
  5. adjusting the hardness and specularity of the sphere

This is workable; however, it is usually difficult to get the look of the light just right, as the light tends to become either a hard ball of light or a barely visible glow, which are not always appropriate; and further more I have to work around the fact that the sphere will also reflect light from other sources.

I am wondering if there are better approaches.

2

You cannot make a light object itself visible, but you can create a halo to emulate the sun/etc.

Select the lamp/light you will be using.
Shift s and snap the cursor to the light.
Add a mesh object at the cursor.
Edit the objects and delete all its vertex.
Add a vertex at the centre of the now vertexless object.
Go to the materials/texture panes and make the new object into a halo and adjust the settings for halo as you see fit.

There are other threads that deal with using halos on this forum and at Blender Wiki, that can help you.

Best regards.

cig.

3

Indirect Lighting (Mesh Light) is specifically designed for this. It turns an object into a light source, controlled by the Emit value in the material settings.
In the World Settings click the checkbox next to Indirect Lighting, and from what I’ve done so far with it under Gather I’ve switched from Raytrace to Approximate and added a small Falloff (If you want a star then you might not necessarily want a Falloff because that will limit how far the light effects)

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4

Indirect lighting offers no shadowing, however. This may not be important for a space scene.

If you take that same sphere and render it in an unbiased render system like Lux it will be treated as a real light and cast shadows.

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5

Correct me if I’m wrong, (please do, it’s one of the ways to improve my knowlege base),but doesn’t indirect lighting also add more render time that needs to be taken into account for animations and slower machines? Plus halos give the added benefit of lens flare if wanted.

Also infraRed made it clear a soft ,(alpha style), edge was required, (or so it seems).

An “in camera” emitter object, gives you a bright, hard edged, FLAT looking, shape.

Maybe using an emitter mesh AND a halo at it’s centre would help, but emitter mesh still needs the indirect lighting settings boosted excessively, to generate the light intensity required for sun simulation.

cig.