Radiosity?

[KenH]

With radiosity now incorporated, does that mean an objects surface(shiny) can reflect the image of another nearby object? I want to create shiny glistening reflective ice.

[Jaycephus]

Anyone have input on this? :qu:

[Kruzr]

Hi KenH . . . :)

I could be wrong, ( as I have been in the past ), but I don't think there is any TRUE reflectivity in ZBrush 1.5. :rolleyes:

The best your going to get with reflectivity is by using the, "Materials / Modifiers / Env.Reflection" slider . . . along with the, "Render / Environment" settings. ;)

This I believe is the only way to get, any type of reflections in ZBrush 1.5. Also, you may already know, or be aware of it, but "Radiosity" really has nothing to do with object reflectivity??? Two different worlds. :D BUT . . . we can keep hoping, can't we??? Have a good one bud . . . :cool: Mark.

[aurick]

I believe that Indirect Illumination is one of the features that the developers are working on adding into the bonus upgrade (which is nearly here). See this thread for details. (http://www.pixolator.com/zbc-bin/ultimatebb.cgi?ubb=get_topic&f=1&t=002807) Only the new shadows mentioned in that thread made it into version 1.51.

Now, whether Indirect Illumination will also allow true reflectivity, or if that is something that will have to wait for a more distant release is something that only the developers know for sure. And so far, they aren't telling me. :)

Now there are some very interesting things that can be done with version 1.51 for reflections. Here's an example:

http://www2.zbrushcentral.com/zbc_uploads/user_image-1032166459xac.jpg

This was a very simple example where I played with the new HDRI material setting and the Global Ambient and Global Specular options in the Light palette. There are no lights and no textures used in this image! It's actually natural lighting and a reflected environment!

Here's what I did:

1) Go to HDR Shop (http://www.debevec.org/HDRShop/) and download the HDR Shop program.

2) Go to the Light Probe Gallery (http://www.debevec.org/Probes/) and pick a light probe image that you like.

3) Load the image into HDR Shop and press the minus key on your keyboard several times in order to reduce the whites of the image until the last light source turns grey. Press plus to go back up one step. Save the image as a Low Dynamic Range bitmap. What you've essentially done is taken a floating point image (where color values go from 0 for black to a nearly infinite value for the brightest) and changed it to a standard 16 bit (256 value) image -- something that ZBrush can make use of.

4) Start ZBrush and change your canvas to a square that matches the dimensions of the image. Choose the Basic Material and load the image into the Texture Palette. Fill the canvas.

5) Change the Material>Modifiers>High Dynamic Range slider to something around 6 or so. Basically, you want to get the image to look about like it did before you changed it in HDR Shop -- in other words, put the HDR values back into it.

6) Use the MRGBZGrabber with Shaded RGB on and Auto Crop off to capture the canvas as a new texture. Clear the canvas.

7) In the Light palette, load your image into the Global Ambient and Global Specular boxes. Set the regular Ambient slider to 0 and deactivate all of your other lights. You can now use these settings to illuminate your scene. You'll need to find settings for both of the Global sliders to give the right effect, and you may need to create a shadow-casting light and position it to match the virtual environment (because at this point, the Global Ambient doesn't seem to generate its own shadows).

Anyway, this is a place to start with your own experiments. I'm sure that some of you highly creative people out there can take this quite a bit farther than I have. :rolleyes: I also suspect that the results will be able to be taken to even higher levels ones Indirect Illumination is added into the mix.

I know that this isn't exactly what you had in mind when the thread was first started, but your questions brought the subject to mind for me. I hope you have fun with it!

[Mahlikus The Black]

Amazing stuff aurick!
HDR Shop's DL page is down at the moment but you better believe it will be back.

Thanks for the info and once again...great stuff.

[WingedOne]

That's some great tips there.

I could probably make some custom light probe images of my own via pov-ray, since pov-ray you have the option to use a spherical camera in pov-ray.

The link to download it on the main page seems to be broken on that page, however you can get to the download through here http://www.debevec.org/HDRShop/download/

[KenH]

Thanks guys. It's not what I wanted, but hey, I can live with it now I know. :)

[WingedOne]

For anyone that's curious, I found what's probably the first ever light probe image used for this kind of thing which can be found here :):
http://www.cs.northwestern.edu/~jet/Teach/2002_3spr_IBMR/1982GeneMillerFirst.bmp

And Here's the class assignment page that references it:
http://www.cs.northwestern.edu/~jet/Teach/2002_3spr_IBMR/IBMR_Project04Assign.htm

[Flycatcher]

Wow! That looks pretty amazing, Aurick. Thanks for the info. I'd never heard of either the software or this type of imaging. Definitely going to investigate this further. :tu: :)

Just for the record, the HRD Shop site is now back online, so you can easily get the download plus info and tutorials.