I can see the glitter effect but it is not nice, shiny and obvious! I tried to add a bit of bump because as you can see the glitter effect is not flat in original!
Is there any improvements i can make to the node? because, i believe that the glare will effect the glass as well! (which is something that i donāt want)
It depends on what you set your threshold to be on the glare node. Iād also use the āstreaksā option.
You could try pushing the RGB values of you glitter above to make them brighter - that way they should outshine the glass reflection when you add the glare node with a high threshold.
I think glitter and glints are a difficult thing to simulate properly. This guy has done a lot of research on such things - take a look down his list of publications. Hopefully some of this stuff may make it into Cycles in the future.
First thing to do is to remove the emission shader from the setup! The material youāre trying to make is not emissive, itās just reflective! And therefore, the glare intensity should come from the enviroment and not from the material itself.
For this type of materials, I normally use a similar setup as this:
The lightblue node is used to control the scattering of the glitter. Low values make the glitter very soft and compact, high values make it more scattered.
Thought this is a simplified version, some other improvements and details can be used.
The output color of the voronoi.cell texture has the particularity of each component (red, green and blue) to be uniformly random between 0 and 1. In this setup I use that color as if it was a vector. If we subtract a new vector (the combineXYZ) with [0.5, 0.5, 0.5] from the output of the voronoi, we get a new vector that has a range that goes from [-0.5,-0.5,-0.5] to [0.5,0.5,0.5]. This is quite usefull, because each cell color is turned in to a random vector that has a direction that can fall in any direction from the origin.
But this alone is not enough, as we donāt want vectors that are pointing in the negative direction of the Normal (they would render as black). Thatās why I add the Normal to it, and then normalize it. In the end, the result is a vector that is randomly distributed around the Normal, as the glitter flakes normally are.
The factor of the Add node serves to control how much from the random vector is added to the normal vector.
If I was just to add the voronoi output to the normal, then the result would be pointing mostly to the positive X, Y and Z directions - which is not a very good randomness.
I know the logic may seem a bit strange (mixing colors with vectors, etc), but mathematically speaking it makes sense, and thatās why the result works.
I can later illustrate this, if anyone wants (donāt have the time now, but itās fairly easy to do it).
If itās not brighter enough, than the problem is with the light. Cycles materials (with some exceptions) should be light independent. Forcing a material thatās not emissive to emit light is not a good approach! It makes the material unusable (without tweeking) in any other scenes.
@alborz, hereās a simple illustration of what is happening:
Yes! thatās my problem as well! that is why i tried to add emission and bump to my original material! But maybe the best way for these materials is post processing in Photoshop (to add extra glare?)
Iāve tried the emissive setup in the past, but no success. One problem with flakes that cannot be solved (if they have very random normals) is that no amount of retroreflectiveness can be simulated, and multibounce between flakes before it reaches it eye would rely on heavy caustics calculations - not something for cycles. Doing any kind of retroreflectiveness at all requires you to actually model it, afaik.
The only semisuccessful attempt Iāve done was doing the voronoi -> anisotropic tangent trick, which can sometimes be added to regular sparkle reflections to get concentrated ācircular highlight of higher intensity sparkleā. Search for concentric scratches and itāll probably lead you somewhere. I can not wrap my head around why that actually works though
Another approach might be to render the sparke separately, then increase its contrast before adding it back (in post). Sadly we can not do any tricks to the output after the shading process.
Nice illustration, but what are the vectors like at the start (the textured cube is shown - but the vectors are only shown after they have had 0.5 subtracted).