Holes in facades question

[paulenescu]

Hello,

 

I am new to this forum, i've just registered after searching for hours for a solution to a recent problem. I couldn't post in the technical forums, so i hope it's ok posting here. Currently i am using 3dsmax 2013 and Vray 2.30 for rendering.

 

I have been trying to follow an online tutorial to optimise my workflow, being impressed by the efficiensy and simplicity of the modeling vs the final image of the tutorial. I don't know if it's ok to post the link to the tutorial, so i'm going to explain it as simple as i can.

 

I've ran into a problem when trying to make the facades of the buildings, more exactly the holes in the facades. The first two images are cropped from the original images in the tutorial, showing the object and the result after the render. The third image shows the type of texture that has been used in the tutorial to get this effect, being mentioned there as an "opacity map".

 

The problem is vray glass only works with object thickness, not planes, as far as i know. So my facade, which is practically a plane has a Shell modifier and an UVW Map on top. But when i asign the material with the texture in the Opacity Slot, it doesn't create holes, because of the two sided facade.

 

I think in the tutorial, the facade remains a plane and the opacity map works as he says, but how did he get the facade to work as a glass?

I've tried applying the material directly to the plane, but it looks like anyhing but glass. The holes do appear, but the glass material doesn't work as it should.

 

Does anyone have any idea how this effect can be obtained?

Thanks and sorry for the long post.

Any help would be much appreciated.

Edited May 4, 2015 by paulenescu

[paulenescu]

These are the settings used and the textures.

As you can see the diffuse slot is almost black color for the window frames, the reflect and refract slot are mapped with the third image so that the glass is separated from the frame and in the opacity slot i have used the last texture attached.

You can see the result in the first photo.

 

What i don't understand is how did he make the holes in the object using just the texture, even if it was a plane, while keeping the window frames and affecting just the glass material?

Edited May 4, 2015 by paulenescu

[ryannelson]

Ok, what I think you're asking is how to apply a single material that has Black Mullions, Glass, and negative spaces to a single object?

 

Seems like it'll be easier to just model the mullions and apply its own texture.

[paulenescu]

Exactly. But, from what i see in some of the images in the tutorial, he may have used 2 objects (planes), one cloned after the other - because of the clipping, so there may be two materials.

See attached photo.

 

The modeling part is almost impossible, as there are over 15 skyscrapers, each with a couple of modules of one/two/three floors covered with glass, each with its own texture. So the only feasible method would be by textures.

 

I can attach my max files and textures if anyone wants to try and give it a go.

 

[mikebart]

 

Hey paulenescu, not exactly sure how it was done in the tutorial you read but I've done a quick test using a vray blend material and then composite materials to overlay the opacity maps, might even be a bit simpler, note that some of the composite layer masks have been inverted in there output.

 

Heres the scene:

 

http://www.mediafire.com/download/kg9h4ipd3t9irf5/facade_test.zip

[paulenescu]

Wow, great! That's exactly what i was looking for. Thanks a lot!

Unfortunately, the reflections don't seem to work as they should in my file.

I only get something almost right only with Shell modifier On and Fresnel Off. (first image) But in that situation, there is no transparency to the glass.

In all the other cases, the reflections are not powerful enought.

The last is with the settings you had in the file. (i.e. Fresnel On and without Shell modifier)

Any ideas?

 

Thanks again for the file, it was a big help.

 

 

PS: the tutorial i've been following is called "Minoco Wharf", for anyone curious.

Edited May 5, 2015 by paulenescu

[ryannelson]

Good call. I was going to suggest using duplicate objects with separate textures. It's certainly possible to use composite textures with masks to achieve that effect, but I like to have more control with separate objects/textures because I get confused if there's too much embedded in a single shader. Good luck.

[paulenescu]

 

And this is with all the maps applied to the glass modules. (because of the varying number of storeys)

But the reflections seem too pale.

The objects for facades are planar (without shell) and Fresnel is On.

 

I've attached the scene and the textures, if anyone wants to try:

http://we.tl/uCezdZNuU5

[Peter M. Gruhn]

Other renderers offer architectural glass which is designed for single face, no thickness geometry. I would very strongly suspect V-Ray has that too.