uhhhhhhh picture? The picture will help if you can get it up.
So I'm guessing you're trying to make something other than a yellow sphere or circle. In fact I'm willing to bet you're trying to make a sun complete with jumping flares. A close up sun like you would see in a NOVA episode.
Am I close?
Here's how I would do it with Mental Ray
Start with a Blend material.
SLOT 1: Use Arch+Design material. In the Main Parameters rollout set diffuse color yellow and set reflectivity to zero. In the Self Illumination rollout turn on self illumination (glow) and set the color to yellow.
SLOT 2: Same as slot 1 except make the colors Red or deep orange.
MASK SLOT: use noise set to fractal. Adjust the noise size and high/low threshold until it looks good and fiery.
In Mental Ray render scene> Renderer tab>Camera Effects rollout>camera shaders
Click none next to output and choose glare. Now drag the box into an empty material slot. From there you can adjust the amount of glare and stuff.
Chris
Moderator
So I'm guessing you're trying to make something other than a yellow sphere or circle. In fact I'm willing to bet you're trying to make a sun complete with jumping flares. A close up sun like you would see in a NOVA episode.
Am I close?