1
$\begingroup$

I recently came across this page, in which the creator made the transparent, glowing exhaust effect as seen in the photo on the linked page. The effect is interesting and I want to try and play around with it, or something like it, but I'm not quite sure I understand the method the creator outlined:

It's an array of 25 planes, each with a circular gradient material fading from transparent on the outside to blue to white on the inside. It's kind of a hack but it works surprisingly well.

I've been looking around for a material, or method to create this sort of transparent effect, without the appearance of an edge if I were to create a conical shape. This might be what I'm looking for to create the desired effect.

So is anyone able to clarify what the quoted description means?

$\endgroup$
5
$\begingroup$

For Cycles render engine, a possible node set up could be this:

enter image description here

With the Texture coordinate node's Object output we are gathering the information about where to place the following texture. Object will use the object's origin, rotation and scale, so the texture will be placed in the middle of the plane.

The following node, Vector Mapping, is tweaking a bit the scale of the texture upon the Z axis, as we are going to use a spherical gradient, while what we need is more like a half ellipsoid.

First Color Ramp is needed to adjust the feather of the texture border, second Color Ramp gives the shades of color to the emission node.

Last step is to mask out the emission shader using the first Color Ramp node output as the mixing factor fwith a transparent shader (don't forget to increase the trasparency bouces to at least the number of planes in the array)

Note: to increase the realism, I suggest to work upon the emission intensity rather than the color:

enter image description here

| improve this answer | |
$\endgroup$
  • $\begingroup$ Okay, this seems like it's off to a good start. I think I've recreated your node setup exactly as shown in your screenshot. I get this when I render, though: i.imgur.com/ivmHZSw.png Not sure why the planes are visible as black, but my guess is that it might have something to do with how I created the mesh. I created one plane, then did Alt + D until I had the desired number of planes. The array modifier did not work in the Z axis for some reason, despite working for X and Y. $\endgroup$ – Hiigaran May 14 '17 at 11:01
  • 1
    $\begingroup$ Using multiple object means that the shader will pick each object origins, while you need to use just one for everything. Creating a plane and using the Array modifier is the fastes way to achieve this: dont use relatve offste (plane has no height), but constant offset. About the black spots: did you increased your transparency bounces number? $\endgroup$ – Carlo May 14 '17 at 11:14
  • $\begingroup$ Alright, seems to be working nicely now. One more question: How can I make the whole thing longer? Scaling obviously won't work, since it's a plane with no thickness. Increasing the offset makes very little difference, and decreases the 'resolution', so to speak. Adding more planes to the array seems to just make things slightly brighter in the same area, even if the transparency bounces are increased. $\endgroup$ – Hiigaran May 14 '17 at 14:55
  • $\begingroup$ Oh, never mind. I now understand what you meant about creating the elliptical shape on the gradient. Decreasing the Z value in the mapping node increases the ellipse, after which I would need to increase the array size. $\endgroup$ – Hiigaran May 14 '17 at 15:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.