Questions regarding IBL-HDRI lighting

[gsfcreator]

hey there, poser-octane folks

I'm trying to figure out image-based lighting/HDRi. so, from what I understood, the renderer is analyzing an image and tries to imitate the lighting so that it will match the lighting that exist within the image, right?

so, IBL = infinite light, in a way, right? I have a few questions...:

1. If I want to integrate HDR light studio with my poser-->octane, which version should I get? (I'm getting a trial version. should it the stand-alone or the 3dsmax one?)

2. when I use HDRI, are there any rules as for matching the resolution of the .hdr file to that of the scene I'm rendering?

3. how does regular light emitters integrate with an IBL/HDRi lighting? if i want the general lighting to be IBL, but i want to create my own lights to control the shadows/highlights/catchlights etc, is that an option? are there any rules in terms of power setup? (I want to light with IBL but still have shadows cast with my other lights...i hope that makes sense).

4. is there a way to reduce noise without using the hotpixel removal (it makes the image very soft. all sharpness is gone...) ? more light?

feel free to suggest some good IBL/HDRi tutorials (gonna search youtube now).

thanks

[wimvdb]

Octane's Environment texture section is like the poser environment dome or EZDome but it is integrated in Octane.
Just load the HDR as an image in either Environment Texture or as Sky texture in Daylight.
It is NOT an infinite light, since light comes from all directions. It is more like firefly IDL (Indirect light in Render settings).

1) HSRI Studio - if I remember correctly you have the start the standalone version before you start the plugin Then the plugin will detect it and add new functionality.

2) HDRI maps are spherical or equirectangular.

3) You can use them all together. I always use HDRI (either in environment texture or as sky texture) and then I use Sun and/or mesh lights. In combination with HDRI Lighstudio you can get good results. You basically paint your lights and highlights on your render. It does so by creating a customized HDRI. I prefer however meshlights with IES maps in combination with the HDRI.

4) Hotpixel should be avoided when possible since it makes less sharp images. If there are many hot pixels, i found that usually a specular material was close to a light source. Softening up the specular (roughness) does sometimes help. Or - if the specular material is not visible, turn it into a transparent glossy material.

[gsfcreator]

Octane's Environment texture section is like the poser environment dome or EZDome but it is integrated in Octane.
Just load the HDR as an image in either Environment Texture or as Sky texture in Daylight.
It is NOT an infinite light, since light comes from all directions. It is more like firefly IDL (Indirect light in Render settings).

1) HSRI Studio - if I remember correctly you have the start the standalone version before you start the plugin Then the plugin will detect it and add new functionality.

2) HDRI maps are spherical or equirectangular.

3) You can use them all together. I always use HDRI (either in environment texture or as sky texture) and then I use Sun and/or mesh lights. In combination with HDRI Lighstudio you can get good results. You basically paint your lights and highlights on your render. It does so by creating a customized HDRI. I prefer however meshlights with IES maps in combination with the HDRI.

4) Hotpixel should be avoided when possible since it makes less sharp images. If there are many hot pixels, i found that usually a specular material was close to a light source. Softening up the specular (roughness) does sometimes help. Or - if the specular material is not visible, turn it into a transparent glossy material.

I still have yet to test IES (got plenty of samples saved up from a link that you provided, if I remember correctly). using them is through the same method of using HDRi? (I mean - Emission -->texture-->choose RGB image in "node type" --> select the IES file I desire. I got it right?

thanks, Wimvbd!

[wimvdb]

No,
IES lights are distribution maps. The need to be loaded in the distribution node of the emission section. They are intended for mesh lights.
Load it as a RGB texture for the distribution node and set the gamma to 1. Then in the projection of the texture set the coordinate space to "normal space"

HDRI is not in the material section, but in the environment section, Just load it in texture channel

[gsfcreator]

No,
IES lights are distribution maps. The need to be loaded in the distribution node of the emission section. They are intended for mesh lights.
Load it as a RGB texture for the distribution node and set the gamma to 1. Then in the projection of the texture set the coordinate space to "normal space"

ies1.png

HDRI is not in the material section, but in the environment section, Just load it in texture channel

hdri1.jpg

thanks again, maestro!

[gsfcreator]

No,
IES lights are distribution maps. The need to be loaded in the distribution node of the emission section. They are intended for mesh lights.
Load it as a RGB texture for the distribution node and set the gamma to 1. Then in the projection of the texture set the coordinate space to "normal space"

The attachment ies1.png is no longer available

HDRI is not in the material section, but in the environment section, Just load it in texture channel

The attachment hdri1.jpg is no longer available

regarding IES, which option do I choose from this tree? (there is no RGB texture option):

[wimvdb]

RGB Image

[gsfcreator]

RGB Image

that's what I did! I'm starting to get a hang for octane.