Understanding the different HDR files and uses...

MatCreator

Hello all, I hope we are good and gravy this evening...

So I am getting back into the swing of things and have become very fond of the new daz studio. never used it much, but seeing the new output mandates i dig in. Generally, i am a bryce user, a little carrara here and there, never really rendered in poser, or studio. Anyways......

So after a clean wipe and install of all the latest releases, i am getting used to the 3ddelight/iray systems. in the past, for poser i would use (when i would even render with it) global illumination light set ups, followed by VSS. IBL/HDR became available, but i didnt dig too much. for studio i would cheat, lantios lights or cload 9 domes (by dimension theory). all drastic improvements, but as they arent my go to software for rendering, didnt really matter. so here i am, trying to jump on board with daz studio. honestly, im too lazy and too broke to invest in poser anymore, ive pretty much forgotten everything. and when i say everything, i mean EVERYTHING, lol..... I cant deal with cracking .cr2's in notepad anymore, lol

ummm, forgive me, i tend to blab =/

So. Both 3D Delight and Iray make use of .hdr files, which is great. Ive used them in Carrara, not much in Bryce (why take away from that dreamlike dali-esque render style?!?). In Carrara, its pretty much just for light, Ive learned to use my own sky dome for the "backdrop", Carrara and Poser.

But now that Im actually using them in Daz Studio, I need more info and understanding.....

So you take an .hdr file that you would use for the uberenvironment2. But that same .hdr file doesnt "work" the same. for an Iray render. I also notice that some .hdr files are not even "pictures", they seem to be like vector images of simple color and shapes. Whats the deal with that?!? Those do NOT work in the UE2, but work great in Iray and in Carrara. Im really starting to like the ones i can use as "auto backdrops". Iray gives you an "automatic ground" that will show the shadows, but in UE2 you dont see or get ground shadows unless you use a plane. Is there a way to adjust that? How can I tell or know the difference between which I can use as automatic backdrops for 3D Delight vs similar kinds for Iray? I like the output of both, but have always been opposed to the "hiding the feet", which is done by Carrara users as well.

I also want to discuss some products i bought, both awesome and highly recommended, but i buy stuff to "rip" it apart for knowledge... So if anyone is using Dimension Theorys HDRI Pack 3 (love it btw), have you noticed the dome has "adjustments"? Im just curious why they would not be left at default settings (finite vs infinite). Also, at different angles for the various hdr's, there are times when the character seems to "float".... is that something we can adjust? And if anyone is using ElianeCK HDRI Lights for Iray... I notice two of the presets load with negative settings in intensity. Is that intended, or for effect? NOT THAT IM COMPLAINGING, i just want to know if in doing so it "does" things... We use .hdr's similar in Carrara. Im just curious as to how those work.

I want to get more .hdr's that behave as autobackgrounds for BOTH 3D Delight and Iray, but is there anyway to know before i buy or download? Are they labled or named different? I already have quite a few, went crazy accumulating them when I started using them for Carrara. But OMG the time in test renders! That couldnt possibly be the only way.

Anyways, any info, advice, suggestions or thoughts you could throw in the pot would be welcome to the soup.

i dont know how to post pics as yet =/

Richard Haseltine

The best way to tell whether an HDR can be used for the drawn doem as well as light is from its resolution - a lot of the uberEnvironment sets, especially older ones, have fairly low resolution, blurred, maps though some uberEnvironment sets do include a second, higher resolution, version of the image. Most maps made for use in Iray should be high-enough resolution to use as a background image via draw Dome (but not the default Ruins map).

Fishtales

There are sometimes two HDRI files. One in kb which is for lighting only, it is blurred and only used for lighting a scene. The other one is in Mb and is the image file as well as being used for lighting the scene. Both have the same lighting information. The higher the pixel size of the files the better the lighting and, in the case of the image file, a better background image, a 4k image is better than a 3k one but an 8k is better than a 4k. I have found though that the Iray dome always makes the image out of focus looking no matter how good the original is.

MatCreator

Like many, as a new system to get used to i have many questions. The YouTube videos help tremendously, simply goung thru the key features with explanations AND visuals to match, make learning so much easier. Just diving in and rendering every adjustment and setting until you think you understand what it does is just madness. Don't get me wrong, I like to experiment, but it helps to have "something"... a poInt of reference if that makes sense...

SpottedKitty

Fishtales said:

I have found though that the Iray dome always makes the image out of focus looking no matter how good the original is.

In Render Settings>Environment there's a parameter for Environment Lighting Resolution that I sometimes see tweaked when I load an HDRI properly set up as a Render Settings file. Maybe that's related? I haven't played around much with HDRI lighting, so I'm not sure myself.

Fishtales

The resolution button in environment sets how much of the pixels in the image are used for lighting.

Environment Lighting Resolution - Controls the number of pixels used for the resolution of the polar angle. The azimuthal resolution is always twice the polar resolution. Higher resolutions result in more detail in the visible environment and sharper shadows if bright details of the environment function are small. However, baking times are increased accordingly.