I'm trying to model a spark using Andrew Price's tutorial (Blenderguru), but the sparks always look wrong. You can always see the outline of the ico sphere. I'm wondering if there's a way to soften the outside of the ico sphere (using volumetrics) to the point where it's invisible?

I know that one way to color depending on distance from the center of an object is to add a texture coordinate node, and then connect the object output to a spherical gradient texture node. This is what I have so far: enter image description here

I know the solution is probably so simple but I've practically been pulling my hair out over this, and haven't been able to find anything about it online.

  • $\begingroup$ I've also wanted to do this for quite a while. $\endgroup$
    – Cubit
    Mar 16 '16 at 8:55
  • $\begingroup$ What if connecting BW ColorRamp to Fac socket of the Mix shader ? It seems to be created especially for that. $\endgroup$
    – Mr Zak
    Mar 16 '16 at 10:54

Apparently using a mapping node with a quadratic sphere texture gives the effect of faded edges... and it looks REALLY nice (especially with some tweaking). The node setup in the image I linked is what I used to get a sun-like fade-off effect at the edges.

If you copy the nodes on the underside of my node setup you should be fine, but one thing to keep in mind is that the quadratic sphere gradient is NOT automatically calculated from the center of the object. You'll have to manually adjust the X,Y,Z location on the mapping node to get the gradient's center to match the object's center. I had to eyeball it.

Also, changing the interpolation of the B/W color ramp in the image changes how quickly the color falls off, so it can blur the light at the edges even more. You can add extra control points to further control this.

enter image description here


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