DAZ 4.9 Unable to lights to shine through window or atmocam to work Iray

Danakinobi

I created a scene with an office building.  I'm trying to get a light from outside the room to shine through window.   I also have lights inside the room.   I'm rendering with Iray...  I have Iray shader lights setup on the lamp shades and I also have Iray shader material on the firniture.  

I purchased the Iray Atmo cam to get some lightrays to shine through the window into the room.  I wanted to create a scene with lights from the city, glowing up into the room through the window.  This would also create a backlight for the character in the room.  The atmocam came with it's on photometric light...   I'm using that to shine light from the outside, into the room.   But it's not working.

So far I have tried everything to get this to work, but it appears I cannot get any lights to shine through the windows or get any volumetrics to show.  I have tride Dome and scene, dome only, scene only.   Nothing.  

The Atmocam says that a light is not necessary.  So I'm confused on that part.   I've attached samples of what I'm doing.

I'm hoping someone can give me a clue what I'm doing wrong.

Richard Haseltine

Never mind, I missed one of your screenshots

Try increasing the Lumininance value of the light - which looks like a distant light - by a factor of 10,000. Theer seems to have been a change in unit for distant lights in DS 4.9.

Danakinobi

Richard,

  Thanks for the tip.   I had to really crank up the Lumininance to about 15,000 to get the light to show up.  I thought that was controlled by intensity, but I guess it's different in Iray.

I used an iray photometric light that comes with the Iray atmo cam...   I was hoping that aiming the light at the V4 character would create a back/rim light effect.   Perhaps it's cause I need to add an Iray skin texture to the character?   

Dan

fastbike1

@brephotosocal_326af4b29c

You are correct. The intensity setting does not apply for Iray in Studio. As you found, the Luminance setting is the one you need. Don't get hung up obsessing about "realistic" luminance values.

Your screenshot doesn't look like there is any light behind the figure.

 

Khory

You don't say so I'll check. Did you put iray thin glass on the window? It seems to make a difference as to how much light goes through the glass to me. You also should consider applying the iray shader to everything in the scene. It will speed up overall render time at least slightly.

Richard Haseltine

To get a back-lighting effect you really need materials that are set up to scatter translucently. If you are using the default 3Delight shaders and ;etting DS covnert them to Iray uber Shader at render time that isn't going to happen.

Danakinobi

fastbike1 said:

@brephotosocal_326af4b29c

 

"Your screenshot doesn't look like there is any light behind the figure."

fastbike1     I have a photometeric light that came with the iray atmocamera only...   I was trying to simulate light from the city shining back into the room.   I was also trying to create light rays.   So I used the Iray Atmo camera and Photometric light.   Problem is that if I crank up the lumincance too much...   I'll get the rays, but I also blow out the scene.   So I turned it down enough, just to have light creating shadow from the window frame.

Yes, I'm using iray glass shader on the Glass.

I tried to apply Iray shader to V4 character...   But I don't think it worked.

 

fastbike1

2brephotosocal_326af4b29c

The Iray shader for your character won't make any difference in this scene. It has no impactg on the effect you are trying to achieve. The scene is too dim and your character too far in the background for skn details to matter.

You are getting some of what you want since the city lights can clearly be seen on the ceiling and upper wall. Personally, i don't think the AtmoCam is the right tool for this job, a distant light at the window will do what you want.

Fishtales

If the sphere in the images is the AtmoCam Volume then I would scale it right down. I also tink the camera should be outside the sphere for it to work. I can't look at the moment as I am rendering. You also might have to change the SSS settings and the Angle to get it to show.

Here are a couple of renders using the AtmoCam.

 

mjc1016

Fishtales said:

If the sphere in the images is the AtmoCam Volume then I would scale it right down. I also tink the camera should be outside the sphere for it to work. I can't look at the moment as I am rendering. You also might have to change the SSS settings and the Angle to get it to show.

Here are a couple of renders using the AtmoCam.

 

Beat me to the question, FT...

I don't have the Iray AtmoCam, but for most things, yes, the camera needs to be outside the volume, looking in for it to 'work'. 

Khory

This is true with the atmocam as well.

Oso3D

If you are looking for anything like good godrays, I HIGHLY advise with atmocam (and similar Iray volume effects) is to use canvasses/several render passes and:

Generate one render lit only with, say, the outdoor light

Generate a second render lit with all the other lights and the atmosphere volume shut off (hidden)

Then take the two layers and overlay/blend appropriately.

 

This way you avoid the problems of general lighting turning everything into opaque haze.

 

Danakinobi

Fishtales said:

If the sphere in the images is the AtmoCam Volume then I would scale it right down. I also tink the camera should be outside the sphere for it to work. I can't look at the moment as I am rendering. You also might have to change the SSS settings and the Angle to get it to show.

Here are a couple of renders using the AtmoCam.

Fishtales....  

That is exactly the lighting I'm trying to get for my scene.  Shining throug the window and lighting up the back of my subject.  

I've attached a screen shot of my latest tests

 

Marshian

Just noticed this thread and I'm happy to help out with my product. 

(Edited) I looked at your first screencaps and it does appear the sphere is inside the room, this is good. I've just tested your scene with the Deco room and for some reson I cant get a distent light to shine through that back wall. I tried turning the opacity to 0, turning off the eye for that bone (win_gl) even hiding the floor and the whole back wall! A distant light will not work. Rotate the Atmocam distant light around so that it shines through the open wall where your camera is- it works right? (AuxViewport).

I'm not sure why this is happening but did find a spotlight will, so there is your fix hopefully. Very Strange!

I'm running a test on the spotlight to give you some exact specs...stand by.

Marshian

Update with better ideas- Still not sure whats going on. However- I deleted the room (CD_Walls) and hit undo to bring it back and now the AtmoCam Distant light is casting rays through the back window!

Save your scene! Then try this:

1. Delete CD_Walls and undo
2. Shrink the size of the camera to 20.6% (this will scale the sphere (MAR Atmo Volume) so that it is barely bigger than the room. Otherwise outside the room will be white.
3. In the scene tab I turned off the eye for the bone win_gl.
4. Adjust the Atmocam distant light lumens to about 150000.0
5. test render through AuxViewport

You should be getting some results now. Wills idea about rendering lights/effects in passes will help a great deal.

by the way- I included a distant light because it produces sharper rays than a spotlight.

 

mjc1016

There is another reason to scale the volume to close to the size of the room/area...the smaller the volume the less time it will take to render. 

With some renders I've been doing, I found shrinking the volume down can almost double the speed. 

Danakinobi

Thank you Marshian...

I actually have your product as well.  I sort of tinkered with it...   But have no idea what I'm doing.   I see the cone...  I see the end of it, has the projection.  Do I increase the scale to incapsulate the subject in the cone?  You have a video tutorial?

Anyhew, thanks for the tip on the cd_wall.   I'll give it a go and post my results.

Dan

Marshian

Here is a render and settings for the atmocam light.

For our other product the Marshian Light Projector I'd say tinker with it some more. Look through the projector camera, fit your subject in the frame and render. Think of it as a real projector.

I feel you'll get the hang of it quickly.

Danakinobi

Here is an updated test I did.  Yes...   Deleting the wall and undeleting seemed to get more haze in.   

Bellow are some screen shots.

Marshian

So good to see this! Thanks for posting an update.