Physical Sky in Max 9,any chance porting to Maya ?

#101

mistake !! its not working anymore if you have somewhere to uploaded i can upload it to you !!

#102

can you send it to me on jojprod@gmail.com and i’ll upload it on my ftp and put a link in the thread

#103

Here’s the link to download the architectural library PDF :

http://misterjoj.free.fr/architectural-library.pdf

thanks to Hans_CC

#104

ivobakker,
For the alpha channel problem, try turning on “pass custom alpha channel” in the Custom Entities tab in mental ray render globals.

#105

Thank you, ik will try!

#106

It really works great, bu I still have the same problem as always. How te get the light insite the room.
I attached an example:

  • used the physical sky and sun
  • used the tone mapper
  • only final gather

As you can see the sun and the sky are already quite strong (high multiplier) and the light close to the windows looks really nice. But inside the room it is still to dark.
I switched on the multibounce and 4 final gather bounces.
Making the color of the walls brighter works a bit, but then i starts to remove contrast. And also i does not match anymore with the rest of the materials.

I worked on another room with smaller windows, their it is even more difficult.

I tried to raise the pedestial level in the tonemapper, but the I lose all the contrast.
Anybody a solution ?

#107

this looks great man, can u drop us render time?

u can put some area lights on the windows with drop off and see what u get!

#108

Thank you.
I think it was about 15 minutes on a dual opteron 2.3

In another interior I tried with the area lights. But it did nog give the result I wanted. But maybe I did something wrong.

#109

hm, well dont have any idea…

what about GI?

#110

I think GI is a solution. But it should be possible with only final gather I think. As far ad I know V Ray only has final gather.

#111

yeah i know :slight_smile:

#112

nice room Ivo ! :thumbsup:

ehem, in this kind of scenes you’ll almost allways get better results with FG + GI, mainly due to the fast bounce calculations of GI compared to FG.

so let the Sun emit photons (mayaSun tab -> mentalray -> enable emit photons, and raise the number of photons - ignore the intensity color, its auto computed by the sun shader by default). Note you can enable/disable the photon emission from the Sun shader too, by pressing the ‘Photon Emission’ button.

Another great feature of the Sun shader is that it can emit photons only in a bounding
box you specify to it (Huge rendering speed ups in some scenes and better quality too) ! So select the room geometry and from Sun -> ‘Photon Emission’ button -> choose get bbox from selection to enable this :wink:

also you may want to look into the ctrl_buffers buffer_api tonemapper, its much better
than the mia_exposure one :slight_smile:

#113

Thank you Yashu.
I did some time a quick test with GI but it was far to dark. I think I did something wrong, so i will test again.
Do the photons go through the glass of the windows without using caustics ?

#114

First off, a big thank you to everyon whos contributed to this shader and the thread, especially yashu and zap for making all this possible. I just needed to say that, as its so easy to forget about the people who really contribute to the community, creating and supporing the tools, while just focusing on the people who use them and ooh-ing and ahh-ing at the stuff we see in the cinemas (no less respect going to them, of course).

Anyway, I was just reading through this thread and trying out this shader. So I’ve got a couple of questions too.

I get this error alot when I turn on photon emisson:
RCGI 0.6 error 362004: no photons stored after emitting 100000 photons from light “directionalLightShape1” (tag 599) canceling emission job.
What does it mean, and does this explain why my renders have dropped to a snails pace ever since I started using photon emission?

Noob question : How do I use displacement with this shader ?

Ivo : I had a look at your image, and it looks good. I was just wondering if you’ve built everything there to scale, as in like 100units = 1m. The FG lighting looks somewhat accurate, but I can’t say for sure.

#115

I modelled the room in meters, so one unit is one meter. Does it make a difference for the calculation wich scale you use ?

#116

Sorry in advance for the long, and partially irrelevant post.

If you’re talking about a purely physical standpoint, it does. If I’m not mistaken, the fall off of physical light is the inverse square of its distance, I’m not too sure how to word it. Hence, the smaller the object the less noticable the fall off. A quick fix to having modeled things SMALLER would be to set the lights falloff to linear or even none.

Unlike pure physical renderers (eg: lightscape), Maya is an artist tool, and does not always seem to have relative physical terms. For example, the power of its lights are not measured in Watts or Joules, just arbitarary values. Same goes for alot of the dynamic simulations. (Well they may be under the hood, but for a layman like myself, it can still be pretty confusing). In which case, its right when the artist sez its right.

I’m not too sure if MR physical light is any different, but I think there was someone who successfully used IES profiles with their lights. The effects were quite impressive, but I’ve never seem to have been able to get them to work for me.

So my usual workflow would be to model everything in proportion, then create a cube and scale it to the size of about 1m (or 10m if I was going really big) in proportion to my models. Create another cube 1m in the correct units then match them. Then only go on with dynamics and texturing/rendering. Its a very round about way of doing things, but Maya has all its settings so ingrained to working with cm. I cant be arsed to always reset all my camera clipping planes, grids and default surface creation options.

#117

What kind of glass material are you using?

What you can try (just to be shure that there is no problem in the shaders transparency) is adding a transmat photon shader to the “Photon shader” in your Shading Group.

#118

He Sander!

Just a simple Blinn for the glass

#119

An alternative would be to remove the glass alltogether, and render it as a seperate layer. I’m thinking that this would probably speed up your render as well, coz you wont have to calculate refractions for every photon thats emmited into the room. Though its probably not really as accurate, but It can save you alot of heartache later on.

#120

to prevent MR from calculating all the refractions for the glass you would add the photon_transmat.