Environment vs. Iray Render Issues

DDCreate

I have quite a few environments that I enjoy working in but I find that I can only render them reliably in 3DL. Trying to do them in Iray is hit and miss. When I do that, the renders come across in just a black screen. I asked about this before and understand that it has something to do with a sky dome. The advice I was given on how to fix it was a little confusing and over my head. So bascially this is what I'm asking.

1: How do I know which environments are going to be like this? That way I can anticipate which I will have to monkey around with.

2: In laymans terms, how do I correct my existing environments so that I am free to use which ever Render Engine I want?

3: Who really killed Kennedy?

If anyone knows the answer to at least 2 of those questions, I would really appreciate the info.

Thanks in advance,

prixat

Which environments are you working with?

 

(3. It was The Comedian)

DDCreate

Haha! I love that movie. Well played.

Here are the ones I am having problems with.

http://www.daz3d.com/martial-arts-dojo

http://www.daz3d.com/loft-4-lease-daz-studio

http://www.daz3d.com/dance-studio-add-on-daz-studio (add on)

mjc1016

1.  Any one that loads a mesh skydome....or just about ALL 3Delight ones.

2.  It really depends on how they are made, there isn't going to be one sure, quickm easy way of converting them.  They'll need one by one. attention...some are going to have high resolution hdr images that can be plugged into the Iray virtual dome directly.  Others will have hdrs that are usable for lighting only (draw dome off, in Iray.

Fishtales

I don't have any of those but aren't they all indoor?

If that is the case then one way is to use finite box set to the interior dimensions and add a light HDRI to that for lighting, or make the ceiling an emissive light. There also should be lights that you could add the emissive shader to and set them to real life wattages

DDCreate

I really do appreciate your responses but I don't know what any of that means or how to do it. HDRS? HDRI? Adding lights to emissive shaders and real life wattages? How do you make a ceiling an emissive light? Yes they are all indoor scenes. I just don't know how to tell which  environments are 3DL when I'm shopping. I know I sound like an idiot and I'm okay with that. I'm just trying to figure out how to make this stuff work.

Fishtales

Sorry, I should have read your OP properly. What I said is for Iray, I haven't used 3Delight for a while.

mjc1016

Iray comes with a virtual skydome that accepts an environment map (hdr--high dynamic range image) that will provide both a backdrop and global lighting.  3Delight requires an additional dome/box to be added AND an 'environment' light shader to be used. 

When looking at the item...if it loads a UE2 light and skydome, it is definitely a 3Delight item.

Since Iray has a virtual dome, any 'real' dome will act like an umbrella and block the light (Iray, like in the real would doesn't allow light to pass through solid objects...in Photoreal mode/default).  So you would either need to move the environment map (hdr) to the Iray dome...except that many 3Delight sets use a blurred image for the lighting component (don't ask, it's a very long and not very happy story...)  and a much higher resolution, but low dynamic range (read worthless for lighting) jpg image on the dome.  In cases like that you woluld need to play around with using an emissive shader on a 'real' dome, making it almost invisible and all those other things you were probably told about, elsewhere.

3Delight lights are unitless measures of intensity.  Iray lights are based on actual real world physics, so they use actual light measurement units...stay away from watts as it's more or less a meaningless unit measuring power consumption, not light output (especially if you don't account for efficacy....or how a efficient the bulb is  a 100w incandesent putting out around 2000 lumens and 3.5W LED putting out the same type thing).  

Now for rooms...you light them like you would a real room.  Start with the windows.   Make sure that they are glass....or if they aren't going to actually be seen in the shot, there are lighting tricks...like placing a plane with an emissive shader (it's in the Iray shader folder) in front of the window to simulate the light coming through it (you can also do that with other light types and such, but they are bit more complicated to set up).  You can apply the same shader to a ceiling, etc.  But in all those cases, it's best to use values that mimic what would really be there...no you don't need a light meter to go measure all of it...but a little basic lighting  research (an intro photography book or online lookup) to get some 'base' values goes a long way. 

http://www.pozeen.com/support/lighting_basics.html

About half way down the page is a chart with some common values for typical lights...

Knittingmommy

I have the Martial Arts Dojo and have successfully render it in Iray.  I don't remember having to do anything more than hit it with the Iray Uber Shader to get it looking nice and I don't believe that one comes with a skydome, but if so just delete the skydome.  This renders beautifully in Iray both inside and outside.

DDCreate

Awesome! Thank you Knitting Mommy, that is encouraging. So all I have to do is load the elements I want into my scene, SELECT ALL and then apply the Iray Uber Shader under Shaders? I will try that when I get home. When I view the scene tab, I did not see anything  that said "SkyDome" so I figured I wasn't doing it right since everything so far indicated that was my issue.

Knittingmommy

Yes, that should work.  I didn't do anything special with that set for most of the textures.  The only changes I made were to the banners in the back to reflect the dojo kun for the karate organization which with I'm familiar.  You can see what I did with the dojo if you click on Dojo Render to see it.  That link should take you directly to where it sits in my gallery.  I can't bring my scene file up right now, but I believe I only had one mesh light and the Expanded Godrays for Iray in that scene for lighting.