Problems with my render with glass - anyone know what I'm doing wrong? :)

[JOAN_LORD]

Hi Guys, i've recently noticed a problem with my final renders, it seems that on the other side of the glass the surfaces look like there "contouring" instead of blending, can someone tell me the reason why and what settings I have wrong?



Cheers

[Morne]

have you tried clearing the smoothing?

[JOAN_LORD]

as in a smoothing modifier? there isn't one as the internal walls are flat. Unless I missing a trick with a material setting?

[Morne]

no I mean select your glass, then go to polygon mode (I think the shortcut is "4")
then select all polygons in your glass (ctrl+A), scroll down a bit to smoothing groups, and click the button that says "Clear All"

Also just another thing, does your glass have a thickness? as in 6mm thick or 10mm or whatever? There is some settings in your material you also have to change if your glass doesn't have a thickness, but 1st try the clear smoothing thing

[JOAN_LORD]

Thanks I'll give this a try and re-render tonight, I can see how that might have happened since I use the CAD Architecture "FILE LINKED" into Max, I have some auto smoothing options checked when it get's link, might have been that!

Altho at the same time I don't get his "effect" in my original low quality / res Images....I also loose the burning of the internal spot lights, which makes me think I've lost it due to settings? Yes all the glass has 10mm thickness to it.

[Morne]

jip that will do it, you should always clear smoothing groups afterwareds in max for glass stuff. Sometimes you may see very weird refraction also because of this.

Could you maybe also show your settings of your glass material?
Default vray material should be fine with black diffuse, white reflection and fresnel ticked. For refraction a colour of 250,250,250 and make sure you tick affect shadows and "all channels" for refraction
default of 1.6 IOR should be fine but you can make it 1.5 if you really want to.

Important thing here is to clear smoothing groups in max for imported cad glass

[Neilg]

Your glass is slightly glossy and you've got 'use lc for glossy rays' turned on, so everything behind it is being handled by the lightcache. Check on your pre filter in the LC settings and raise the interp samples to 100, that should help somewhat.

to be perfectly honest, because it's only slighty glossy it may be worth rendering it sharp with a channel to select it and blurring the refraction pass/re-building the glass in post. it'll be much faster and save any issues like this.

Clearing all your smoothing groups on that object is going to split the reflections into vertical strips around the corner, i'm not totally sure you'd want that.

[Morne]

curved glass is expensive and people hardly ever go for it. These clients mihgt have the money, who knows. Otherwise it's better to always model glass in straight panels

[rivoli]

as cubicle says, those look like lc samples. if that's the case, you can even try and uncheck "use light cache for glossy rays".

[JOAN_LORD]

Thanks guys for posts, I think your right, I used to have this option always ticked in my template file but I must of forgotten to switch it off, it does save loads of time but hardly a great result with the interp samples so low...

Were using curved glass as it's only a competition, so it's what ever looks the best, the compromises and reductions happen if and when we win it lol...

Cheers

[JOAN_LORD]

Yes thanks for everyone's input, yes it was the Subdivs / glossy rays problem, so switched it off and increased the Samples and looks peachy now! Cheers.