Mies van der Rohe - Tugendhat villla onyx wall material experiments


#1

Hey, it’s a subject, I wanted to render for a long time, now I started to fool around it, and tried to achive something convincable in appleseed also. When the afternoon sun hits this onyx wall it starts to “burn”, it’s beautiful. I want to miic the effect. So the best solution would be some kind of sss, but this disney sss is something that can’t give the effect of this translucencish feel. There was some kind of fast sss material back some release ago if I remember correctly, there was an example scene for that with a green killeroo mesh. That material would be great, but now I can hardly achive something like this. So this image is a big cheat :smiley: The burning areas emitting light, so far this solution seems to be the best, I’d really appreciate som ideas to create a mat like this!


#2

Interesting, this looks nice and intriguing!

You remember correctly: There used to be a fake SSS surface shader a few releases ago. It wasn’t a true SSS implementation that you could have used with appleseed’s path tracer, it was more a demonstration of how to mix physically-based rendering with non-physically-based shaders. It had little value and was confusing people so we decided to remove it.

The SSS effect of the Disney BRDF is not intended to be a full SSS implementation either; instead it’s meant to provide softer lighting to mimic SSS.

We don’t have a true SSS implementation in appleseed yet, but we will at some point.


#3

Getting closer. Diffuse translucent and disney blended in this test.


#4

I didn’t know what you were trying to achieve so I googled it. Lots of beautiful scenes to study and reproduce!

What’s the main difficulty with this wall?


#5

Welll I think if I fine tune this material setup I used, I can achieve something closely as nice as in reality. Mainly the thing is that the walls translucent areas are so bright as they were emitting, and well visible even if the wall itself is lit from the viewer’s side also. Here’s a good example: http://www.lessingimages.com/viewimage.asp?i=14030350+&cr=2&cl=1


#6

Wow! I think I understand what you are trying to achieve: The wall is thin enough that high light generate a nice effect going through the marble when you are looking at it from the other side. Am I right?

Yeah, there is no SSS way to do such interesting effect with appleseed. What I would try is to use many (ten? hundreds?) of half transparent plans (no BRDF on them) with various (but almost identical) subtle marble alpha and use a geo bouding box on this planes with a true transparent glossy BRDF on it. This way you use your planes to reproduce the SSS “feel” and the transparent glossy material to make everything look like marble It’s a hack but is shoud do the job.

I have no idea about render times indeed. ^^’


#7

some progress: I’ve modelled the chairs of the study. I think the reason why it doesn’t seem so brght (I mean the onyx) is that the overexposed enviroment ivisible and it attracts both human attention, and the compositor also doesn’t take it in count as highlight. As I create the rest of the scene: the curtains around as on the photo and vegetation outside other furnitures etc. it will be more and more visible. We’ll see… Anyway here’s an update with the chairs:


#8

Very nice, looking forward to the full scene :slight_smile:

What’s up with the noise on the background plane?


#9

Well the scene is lit by a sun lamp and an enviroment exr image which is black under the horizon. I think appleseed can’t sample this hard transition of the image, but it will be covered by the vegetation, so no problem. Oh by the way the log says it’s a problem that the enviroment texture is not tiled, is t really a problem?


#10

[quote=“jarmaizsolt, post:9, topic:47, full:true”]
Well the scene is lit by a sun lamp and an enviroment exr image which is black under the horizon.[/quote]

But shouldn’t the plane be lit by the upper part of the environment map?

It’s a problem if all the textures cannot fit in the texture store (whose size can be set from the Render Settings dialog). Otherwise it doesn’t matter. You can inspect the texture store statistics printed when rendering ends to check the maximum size reached by the store.


#11

uhm… sure it is like that. Buta if you look directly at the black part there’s some noise generated by the renderer. It is like that in some other renderers also I’ve been using. It’s ok I guess. I’m not sure if I understood your question well, so maybe the answer is not adequate either, if it is so, sorry! :smiley:
Anyway, here’s some (small) update:


#12

Do you think you could send me the scene so I can check what’s going on with that background plane?


#13

sure. here it is:


#14

Thanks!

I get it now: the noisy black “floor” is actually not shaded geometry, but simply the bottom half of the environment map (which for some reason isn’t pure black, but has noise in it).

I compared performances between the original (non-tiled) env map and a tiled version made with the maketiledexr tool that ships with appleseed. The main advantage of using a tiled map in this scene is that you get full rendering performances sooner during interactive rendering. Eventually rendering performances with a non-tiled map are the same, you just reach them at a later point (I suspect the reason being that with a non-tiled map, many texels are loaded but are never actually used).


#15

exactly! I couldn’t describe it properely… :smiley: