Spherical Sky Background - Iray

JigSaw73

OK, I don't know why this is escaping me, but I can't seem to figure it out - so please help if you can!

I would like to have a scene lit using the "Dome and Scene" option - I have an HDR file that acomplishes this easily. BUT I also want to add my own spherical background (mapped as a background) that doesn't affect the lighting at all - using a different image thant the HDR I'm using for lighting. So when the camera rotates, the background is realistic. I can't seem to acomplish this with the "Background" image in Daz Studio - it doesn't rotate with the camera.

What am I doing wrong...? ...what step am I missing...??!?...

 

Thank you in advance for you time and help.

 

Ruphuss

if you talk about the internal Daz Backdrop

it cannot move

kitakoredaz

Actually I feel same difficulity to use HDRI light-source, and spherical mapped Back ground high resolution image. I used sIBL packages in blender, with plug in, or I could it in 3delight . there is good free utility to correct uber-enviroment axis problem.

but Iray is more better to achieve render with these Enviroment light, (or GI ) in daz studio, I think. then I hope to use it as same as sIBL way. sIBL is usually packaged three image files as minimum 1 low resolution HDRI for emission, 2 high resolution HDRI for supecular surrondings, 3 high reso background LDR (midimum or low  range images. )

I can make new sphere and apply emission shader with diffuse and emission, then use it as background only and can set scene light, with tweaking color or intensity values, but in this case, I can not use HDRI light source,,,(it should fit backgorund) (and can not use reflection map too,for surrounding, or there is way to setting well ?)

Then I tried with two env sphere, 1 light_env 2, backgorund_env. without iray enviroment background,(scene only) but actually I could not manage them well, or they cast strange poligon shadow, some case.

usually it seems best, I simply add high resolution specular HDRI for light source and background for iray dome.(but I do not think it is correct, just feel it show me better than others)

I tried many setting, about my original double env sphere,

eg  set thin wall,then apply background image for normal face (diffuse and emittion too), but back face are transmitt (specular reflact) only, for backgorund_env. then add (wrap) by light_env with light-source lowresolution HDRI, but it seems not work well what I expected,,

I am now thinking to ask about it in iray-forum,,, if there is way to use different spherical image for light-source and back ground image.

===============

I know,, if I render two  image, 1. light source only, without dome (no background image) ,then save it as PNG,

  2, use low resolution background,image as lgiht soruce ,and backgroound without scene obj,,then render it,

,, after that compositing,, but it seems not best way for me.

Szark

The proper way to use HDRIs is just that a HDRI that has a big enough resolution for reflection etc. But the HDRI needs to be high quality, many freebie are too low a res and not enough light information.

kitakoredaz

Szark said:

The proper way to use HDRIs is just that a HDRI that has a big enough resolution for reflection etc. But the HDRI needs to be high quality, many freebie are too low a res and not enough light information

Yes , (though I do not know clear, the High resolution HDRI which offfered for relfeciton env in sIBL sets is better than low resolution HDRI which offered for emit light, as light source,) but if I can use high resolution back ground image with simple HDRI (it just for emission) it much with Back ground image (color direction,,) I feel it is best (without I need to render product image etc,,) then serch way. or I must need to buy iray product.. I am hobby user, then may need not so perfect HDRI. just serch better way.

Szark

No the relfection HDRI is for light also and will do a better job than any low res HDRI in terms of light. Any quality HDRI can be used in Iray.

So if you have a high res HDRI for reflection then use that as a light source. So rule of thumb is the bigger the file size of the HDRI the better.

kitakoredaz

 I really feel difficulity to clear understand,,  when  native  use "no" and "yes" with mixing, any , alsot  etc,,  , (though it should be basic english I know,,)

google translation not help me lot,,

then simply ask, Szark  

which image you choose,  for iray dome,, (not only use for emission ligh, but as background,,)

if you only get one  sibl set , but can not buy or get  perfect high resolution HDRI (use for emisson, and background perfectly)

 

1  low resolution HDRI for emission,  (eg daz default iray env image) ) sky_env.hdr (600k)

2 high resolution HDRI for Reflection ,

(have you used sIBL set ever ?  I hope to know what actually usage ,,though I use it for emission and background when I use it for daz iray dome,,

but in blender with sibl plug in,, it auto work (then I need not to understand detail ,,,just controll ground plane or color etc,, about light and source)

3 high resolution  background  8k jpeg

maybe your answeir is 2.. right?

 

then,, do not you simply  hope to use 8K jpeg for background,, (not get rale High range color  emission,, but as  diffuse color as back ground) with light soruce HDRI?  

 

Szark

Any HDRI will provide light, just because it says Reflection doesn't mean it cannot be used for light and because the reflection HDRI is a larger file it will produce better lighting results, generally speaking..

Yes 2 is right, you put the Reflection HDRI in the Iray Dome channel and the Turn on Draw Dome On to get a good clear background and light.

 

IBL mean Image Based Lighting which a HDRI is.

Blender uses HDRI a little different as we can add to the light via Sun Light to make better directional shadows. Iray works different.

kitakoredaz

OK, thanks but,,  I think if you do not  know sIBL clear  . sIBL is package  of images to achieve IBL easy set-up, and low render time.

http://www.hdrlabs.com/sibl/ 

 

 

 

Szark

I know what IBL is and HDRI is an IBL (Image Base Light) what you have to take into consideration is the render engine and how it use IBL, some differ but nearly all unbiased render engine use HDRI the same. Now when it comes to 3delight your way of using a low res HDRI for light and a High Res HDRI or JPG as a background works nicely. A low res HDRI in Iray will case you problems and longer render times as I showed in my render thread the other day.

Szark

PS even 3DL uber srface can use a reflection HDRI in the reflection colour channel of the surface so you can get even quicker results.

Dartanbeck

Szark said:

Any HDRI will provide light, just because it says Reflection doesn't mean it cannot be used for light and because the reflection HDRI is a larger file it will produce better lighting results, generally speaking..

Yes 2 is right, you put the Reflection HDRI in the Iray Dome channel and the Turn on Draw Dome On to get a good clear background and light.

 

IBL mean Image Based Lighting which a HDRI is.

Blender uses HDRI a little different as we can add to the light via Sun Light to make better directional shadows. Iray works different.

True.

Even non-HDR spherical images will provide light in the dome

Szark

yeah but again not very good light. :)

kitakoredaz

Hi yes I know usually relfection map work so, but SIBL packaged reflection map is not for the purpose,,though you can use it,

for each surfaces shader, as reflection map.

 But the sibl reflection map is mostly applied  for enviroment sphere as same as back ground image. but for reflection color only.

http://www.hdrlabs.com/sibl/formatspecs.html

"The more generic setup is to map this reflection image on a large sphere, just like the background image. Make sure this sphere does not cast a shadow, has no influence on global illumination, and is invisible to the camera. It should only be visible to raytraced rays. "                   

 

I know each render use IBL different way,   .And of course,,  I know,,  jpeg or any image map can emission  in iray.  (it is not only about iray dome, all surface

should be applied any image for emission)  as you said. 

But  I think same thing " but again not very good light"  to  use HDRI high - medium  resolution image  made for reflection , as light source and back ground.

though If I need to choose one, I use it, but it means,  I coud not find best way still.

 

prixat

About the "sIBL" sets... They are really designed for biased renderers.

If you want to use all the files in the set you need to put each file in a seperate Environment dome.

Seperate domes allow you to set up the set for whatever requirements the job may have:

For example in Cinema 4d I use 3 environment domes, I can use the compositing features to use the Environment HDR for GI calculations and exclude it from Raytracing. (That is the official way sIBL sets are meant to be used, but we don't let that bother us!) 
...you could use the Environment HDR for diffuse, the Reflective HDR for specular and the JPG for reflection.
...or mix different GI algorithms to maintain render speed.

You can probably get something similar set up with 3Delight in DS.
...but the problem with Iray is we currently only have the one built-in dome and DS does not have the more comprehensive compositing methods that a program like C4D has.

Szark

well said prixat.

nDelphi

JigSaw73 said:

OK, I don't know why this is escaping me, but I can't seem to figure it out - so please help if you can!

Read this article, the information you want is in Section 2 (Iray Image Based Light).

http://thinkdrawart.com/daz-studio-iray-tutorial-for-beginners

kitakoredaz

prixat said:

They are really designed for biased renderers

yes I think so. then serching best way use each maps correctly apply for un-bias iray render. as same as use them for cylces with plug-in set-up. it is all what I asked here.

But just use  High resolution HDR  reflection map in sIBL set for  iray-dome  can not answer of it.  But  I often get reply so.

prixat said:

you could use the Environment HDR for diffuse, the Reflective HDR for specular and the JPG for reflection. ...or mix different GI algorithms to maintain render speed.

it is what I trying now. but May not need to use all of them. (then may not need to use three env sphere. at start point,I am serching way to set background diffuse, and use low light source . with iray dome and user made env sphere. (or product)

prixat said:

You can probably get something similar set up with 3Delight in DS.

Yes I have some nice plug in too.  thogh I need to apply reflection map for surface which I need.

 

prixat said:

but the problem with Iray is we currently only have the one built-in dome and DS does not have the more comprehensive compositing methods that a program like C4D has..

I was thinking it can be achieved by user made double or single env + iray dome, but difficulity is, actually how set shader (not only about daz iray uber, user made MDL too, I think it need  not complex shader) correctly, and  set up these env_sphere,  and iray dome.

then ask here or there, (now I asking in iray  MDL forum too,, it is not dobule post, I think,,) to find actuall set-up with two env (or with iray-dome)

mjc1016

For Iray...the 'reflection' map in the sIBL package is the best choice to use as a general, all around image.  It is an hdr image and has sufficient information to use for lighting purposes and has almost to enough resolution to provide a background image.  The diffuse map in the sIBL packages is pre-blurred to use for lighting only...it is NOT needed for Iray (or anything really...it's a 'crutch' from when machines didn't have the capabilities they do today).  It also 'masks' lower quality/range hdrs...it will extend the usefulness of them somewhat, because it will sort of 'stretch' the bright spot and even out everything to make it more uniform.  It will do nothing to enhance the shadow casting ability of the hdri or actually extend its range.

kitakoredaz

OK  yours  only use high resolution HDRI reflection map, in sIBL  with iray dome.  . it can show you best render.

But  I serch  way  to use simple spherical map ( not HDRI)  as bg  with different light source ( low HDRI ) or scene light.

 

 

 

 

 

prixat

I saw your post on the Iray forum.

Have you had an answer?

We need a "hide from camera" option like Mental Ray had.
I think the Path Tracer in Iray is full-time so hiding may not be possible.

I don't know enough about Interactive mode, I wonder if it allows more flexibility?

kitakoredaz

@pixart

yeah now I get reply  . but  modelator (very kind and clear guide,, then I could  understand well  what he said when I asked  there,, ,)

teach me again ,,, almost same thing which others reply here ^^;

(mmmmm,,,,,,,even though,, it is recommended to  use high resolugion HDRI ref map for light, reflect and , backgroud by mdl forum  modelator,,

 I hope to use different image map and light soruce when I hope ,,,when I feel , ,  I want to know the way!  , then,, not give up!!)

then   you may find discribe about LPE and , iray back plate..  I do not think, now daz offer iray back plate already,, is it?

anyway, I am seeing the LPE document now , and start learning, (I thought about light path and compositing,,  but not understand clearly how it work

about iray in daz stuido,, I hoped to tweak each light path as node same as cyclies compositing way,, then,,  I do not know about canvas well ^^;

mmmmmm,,,daz please offer  more easy but clear detail guide about daz iray and tools,, ,,,without it

I should ask about daz studio ,,in  iray forum  often,, then may start  complain about daz iray document,,,,  ^^;   

,,but  not hope I  kicked out from iray forum,, then I must keep good attitude keep good guy,, ,,never say complain in iray forum