anisotropic mirrow reflections ???


did anybody find out if it is possible to in addition to anisotropic specular also to have anisotropic mirrow in 242???

i figured out how to work decently with the anisotropic specular but
sofar i am unable to find the same effect for reflections.

any clue?

You mean the blurry reflections caused by
scratches and or tiny pits in the surface?

anisotropic mirrow reflections follow similar to anisotropic specular reflections. they are not only blured.

i spent few days with mental ray and blender. i noticed that mayas anisotropic specular shader is not more bullet proofe as blenders. it is smoother but also seems to produce some bad results depending on the mesh. however the mirrow is more realistic in mental ray. when an onject is far away also the reflection is less strong (intensity) and the closer you get the more clear and stronger is the reflection. i was not able to reproduce that with blender. well mental ray has a much better AA. i am not sure if blender uses an adaptive over sampling or just a straight oversampling. but one pass even with 16 samples is just not enough. i was able to produce a fine noise pattern which is smaller than a sceen pixel in mental ray. and that created a much finer fake blured reflection.

Well for the release of Blender 2.24 there needs to be
a demo of the anisotropic shader.
Would work on that shader with me?

I could us some help with this. I got all the modeling done.
I also have a few textures done. Just need help with texture
mapping and shader settings.

The goal is to produce something in blender close
to what was done in this tutorial.

hi well what do you need to get done?
i figured out the anisotropic shader, while not a big fan of it because it works not good.

you need to unwrap you model and the U and V coordinates will create to gether with the tanget V option anisotropic specular highligts.

however i found that you need a high dense of a mesh to even get regular and smooth higlights. otherwise they go in snake lines (because of the underlying mesh geometry/density)

So there’s no way to get results like at the link I
posted to the tutorial at cgarchitect?

The shader ain’t that bad is it?
Show me an example if you would please.
You can PM me if you’d like.

Blender’s implementation is even more of a ‘hack’ than yafray, but that is typical blender. Nevertheless, somewhat similar approach, but blender’s method allows any specular shader (as well as diffuse in fact) to be ‘warped’ for anisotropic shading. And like yafray, it is only shading though, no reflection. I suppose you could try the old method of a fine scaled bumpmap texture, possibly scaled in one direction so that it is stretched.
Not that it is of any use to you, but yafray does allow smooth shading without the need for uv coords, though as I explained several times before, it won’t work well for animated deformed meshes.
Of course, if you really want better reflections, then you could of course try other renderers like sunflow or kerkythea etc.

There is some hope though, throughout the release logs you read of a hack or two that gets changed into a more proper implementation. Perhaps by some user who’ll take advantage of the new render API.

hi eeshlo,

the nice part about is that in deed you can select all specular light models as a possible anisotropic like specular highlight.

I actualy tried out so many bump maps from 500 to 3000 pixels but with blenders limited and static AA i never got the fine results I was looking for.

I used the same maps with mental ray and well of course with higher rendertime I got the fine results. with blender it seems that always a noise point is as big as a screen pixel and no smaller as a screen pixel. as a result the brushed metal bump map also looked rather course than fine.

What is that smooth shading in yafray? i never heared about it. can you explain that a bit?


i got your scene nearly rebuild in blender. spent most of the night for that :wink:

give me some more time and you have it all today including layerd shaders materials as in the tutorial. the only thing i cannot rebuild seems to be the anisotropic reflection. i cannot assign a fall off to that in blender. mh but well that should be possible with a fixed alpha map affecting the reflection channel.

I want to make it clear that the scene
in that tutorial was done by someone else.
It is not my scene.

I just posted it as an example.

If Blender can’t produce that then my guess
is that the shader is not correct.

Also will let you know I’m working on the Figure 3
scene from An Anisotropic Phong BRDF Model by
Michael Ashikhmin and Peter Shirley.

I’ll PM you with an image.

I know you did not build that scene.

I rebuild the scene in Blender already. Sphere, box, cone, and cylinder
are already unwrapped and shaded. I am just fine tuning the materials.

in 30 min i am done.

what do you mean you work on the figure 3? are you coding that light model MA explained in his paper?


I’m trying to reproduce the scene in blender
using Blender’s render engine as well as YafRay.
I am using YafRay first.



here it is:

here is the Blend file:

Rotating the UV will rotate also the specular direction. The best is to unwrap as a cylinder. Sphere works as well. But a high poly counts is required to produce decent smooth highlights.

have fun

Your links are not working.

Upload the file here and post the link to the file.

Oh and another thing, your subject line
contains a spelling error.
Change mirrow to mirror.

Mh my file works fine, I d/l it and opend it.
Well maybe I will save it as a zip.

I tweaked the material a bit more and added a second specular relfection to it. makes it look realy much better. it simulates the also the blured specular better. I took some metal object and brushed them to use the as a reference.

Yes It would work for you because If I’m not mistaken
your in Germany. Well I’m in the USA.
Anyways I’ll just PM you with my address
and you can e-mail it to me. :slight_smile:

ah well the server is in germany, thats true, while i am in Ohio.

but i can access (up and download) the file from here (Bowling Green Ohio).

anyway i send you an email with the file attached!

That’s funny because I’m about 100 miles from Detroit.

did you get the email ?