VRay glass shader & "Shell" modifier in Max

[bolex]

Hello I am new to the forums and new to VRay.

If this is a known thing, and has already been discussed to death, months or years ago, just tell me shut up and please point me in the direction of the knowledge I seek.

Has anyone noticed any trouble with the Shell modifier in Max and VRay glass type shaders?

Specifically, glass objects that are using the shell modifier for "wall thickness" that look strange when rendered. It looks like something goofy with the normals, yet they appear to be facing the right direction in the viewport. Should I not be using "Shell" to model the thickness of surfaces if they are to be made of glass? For example, a bottle, jar, cup, etc.



Sincerest regards,

James Russo

[DaForce]

Shell is fine to use with glass objects.

Perhaps you could post some images to demonstate the problem you are experiencing.
You can host them at imageshack.us

Oh and welcome to the forums

[bolex]

DaForce

Thanks for the welcome. I will get some images together. The model is just a basic glass bottle as kind of an experiment. I made one with a "rounded body" using the Lathe modifier and it came out fine. But this one has a "rectangular body" and uses Shell on an editable poly object.

James

[DaForce]

Cool, well it certainly shouldnt be a problem but it all depends on the resulting mesh of the shell... maybe something funky was going on there.

But get those images up as well as maybe a wireframe and plain gray render of the mesh just to see if it looks ok.

[studioDIM]

make sure you check "straighten corners" in the shell mod: it has a tendency to "cut" corners, especially with right angled faces, if you do not.
Also, make sure double sidedness is off for your glass, unless you want internal reflections (which may lead to artifacts when set too low).

But please do post images, so we can lay our fingers all over them :P

Lele

p.s.: welcome aboard matey

[bolex]

First of all, let me say that you guys rock!!! The fact that with minutes of posting my issue, multiple people are offering their help is amazing to me.

I just registered at ImageShack and below is a link. Don't make too much fun of my simple model, as I am somewhat of a noob when it comes to 3D -- especially compared to the rest of you serious 3D animals in here.



It almost seems to me that the "walls" are one sided or something. Or am I crazy, and it is just because the surfaces are so flat??


IMAGE IS HERE:
http://img216.imageshack.us/my.php?i...eling04jy4.jpg



Kindest regards,

JR

[bolex]

Here is a link to the "round body" plastic bottle I made. The shaders I used are very similar.

Thanks again.



http://img215.imageshack.us/my.php?i...zbttl01gw3.jpg

[DaForce]

Hey

I just tried with a cube that was shelled, and also modelled to have the same affect as the shell. The renders were identical.

The blue one does seem a little odd. What happens when you change the refraction exit color to a bright red? Do you get much red in the render?

[bolex]

I just tried changing the "2-sided" and "staighten corners". The results seem to be nearly identical however.

I am going to change the refraction exit color now.

JR

[bolex]

It occured to me that the angle of the image I originally posted may not be the most useful angle. Here is another angle that makes it look even worse...so I got that goin for me which is good. (Fletch)

Worse angle image
http://img208.imageshack.us/my.php?i...dangledsa3.jpg


Also there is this image which shows the "red exit color"
http://img208.imageshack.us/my.php?image=redexitxe7.jpg


And this image which shows the original (LEFT) and "red exit" (RIGHT).
http://img208.imageshack.us/my.php?i...ottleabbe7.jpg


Thanks again for the input and help -- I sincerely appreciate it.


James

[DaForce]

hmmmm weird

Drop an STL check on the mesh and tick check errors and see if it has any errors. If not delete the mod if it does then well.. the mesh has errors.. hehe...ahhh

Care to post the mesh perhaps... email it to me maybe? It does look kinda of odd, but that could just tbe the reflection environment, reflection depth, or even the mesh.

[bolex]

I used "STL Check" on the model and it came back with no errors. I have never used STL Check before...that was cool.

I would be delighted to send you the file...are you sure? I don't want to be a pain in your neck though.

It is possible that the "flatness" of the surfaces is contributing to the wierdness of it.

James


PS - To StudioDIM: If you are still out there, you may get a kick out of this...I went to my mother's house for dinner tonight and she sent me home with a large plate of eggplant parmigiana. I am about to eat a huge sandwich...mmmm...cooked with love.

[Paul Oblomov]

Yap. There's smth with shell modifier (a friend of mine made me say wow, when shelling car glass mesh made smth weird with refraction). Can you post the scene, so I will check it in max9 ? As I got strange feeling it will be fine there.

[DaForce]

yeah stl check is great

Yeah you can send it thru to my email.. just click on the email button below my post.
Or if you prefer you can post it here so others can check it out as well.

Your call.

Have you tried just cranking up the max depth for the refraction? to say 50.

[bolex]

I would have no problem posting it for everyone to look at, especially if it may help others.

We won't have any trouble as long as you guys don't make fun of my modeling skills which I'm sure aren't perfect, as I am a self taught noob when it comes to the "3D aspect" of production. (he he he) ;-0

How can I post the file here?


Are there always a bunch of people online helping each other here? As I said earlier, I am a new VRay user and still unfamilliar with the VRay community.