Faking HDRI's with Mac

[bjotto]

:buttrock: :applause: :buttrock:

[amapimaster]

Great stuff -

Right thats my sunday evening sorted out..mess, tinker, render etc etc..

Ta very much

[LucentDreams]

I would like to point out that with R8 mac users will be able to load HDR images directly into XL. VEry nice and ample files are really handy

[matty2x4]

while we are on mac user issues... can I ask how do I get my mouse scroll wheel to work? microsoft intellipoint mouse. The side buttons work fie (forward and backward through windows... very handy) but I cant get the wheel to do anything...
thanks

[Per-Anders]

did you install the latest drivers? you should be able to change it with the settings from the control panel. otherwise if you're in osx you should get scrollwheel support directly without any driver (i do with that mouse).

as for hdri... hmmm... lemme see what i might have in my ikle toolset, but i gotta go and get stuff for the kitty now :) back in a while

[derwolpertinger]

really nice news kai! :buttrock: :buttrock:

[Per-Anders]

it's very good news :) but here's a little tip for those who're having problems getting those nice HDRI shadows and good contrast using the method shown on that link. In order to up the contrast without messing up the background (if you want the HDRI to still be there as a backdrop) try the following.

Create your scene, on the sky object just map the fake HDRI image normally, the reason for this is because we're going to use the Sky object to show the HDRI, not to calculate the Global Illumination effects. It doesn't matter if you multiply this in luminance (you can if you want for added contrast to the background or whatever) but it's just there for making a background, and giving something for your shiny objects to reflect... it's not creating the actual lighting. Then add a render tag to the sky object and untick "Seen by GI".

Next make a sphere, set it's radius to be huge (i.e it's gotta cover the whole scene) i made mine 10000m. This is going to create te GI HDRI effect on our scene, only with a little bit more control than you've had in that tutorial. Before we make any material for set up the tag on the sphere, so put a render tag on the sphere, and untick everything apart from "Seen by GI". This ensures that the sphere doesn't render, but it's effects do.

Now for the material to go on the sphere just use the luminance channel (i.e. switch all the other ones off). In the luminance channel, set the brightness to whatever you want... i suggest around 1000 to start off with and add in a fusion. Set the Mix to "Multiply" and edit the fusion. In the top channel put in something in a shade of grey or white or black, it's not important which shade, just that it's a completely unsaturated colour, so you could use a gradient with black at both ends or whatever. In the bottom channel put in a BhodiNUT Brightness Contrast. Set the blending mode of the fusion to be "Saturation" and set the mix to be around the 80 mark. This will now control how saturated the HDRI effect will be (or how Juicy the colours will appear to put it another way). Now edit the Brightness Contrast, put your HDRI image into the Brightness contrast and change the settings to really highlight the lights, i Just lowered the brightness by about 3% and raised the contrast by about 20%. Use your eye and look at the preview you get, you're aiming to get an image that's mostly pretty dark (or even black) with a couple of bright areas where the main light sources are. This is because otherwise HDRI lighting can leave you without true shadows in C4D, by upping the contrast we're able to control how bright the lights are, and how tight they fit to the light shape.. thus controlling the overall lighting so that you get much tighter sharper defined shadows in your scene. Now go back to the fusion and just try to match the saturation to the saturation of the original HDRI (do this by moving the blend ammount, the higher the blend ammount the less saturated the image, meaning it's more grey, the lower, the more juicy, now you understand why we need to do this because the brightness contrast can make the image far too colourful, so this is how we compensate). Then apply this to your GI sphere (the huge one we just made). The whole putting it in a fusion and using brightness contrast just allows you to match it up to the background, whilst focussing your light sources as otherwise C4D over difuses everything and you get too soft shadows etc...

Nest we change the render settings, you need to switch off automatic lighting in the render settings->options. You may find that the resolution of the radiosity pass goes down a bit as a result of doing this, so the next thing to do is to up the accuracy of the radiosity in the render settings dialog box, you can also play around with the max & min samples to get a better image, with a little tweaking of the Saturation, Brightness Contrast and overall brightness of the luminosity channel on the GI sphere you should be able to get a much more satisfactory HDRI style image in C4D.

Hope this is useful to anyone needing to create HDRI in C4D.

[Per-Anders]

here's a very quick test just to show that the shadows are indeed improved... (no lighting apart from GI Sphere)

[prayas]

pretty nice link so!

mdme_sadie this is the right method! Never use sky objects or ground objects when working with GI or Radiosity! Gonna push the render time to a limit! Working with the sphere idea drops the rendertime to the half!

kaiskai! Only one little question! Is HDRI built in or is it just the function to map .hdr data in R8? As you said for mac it will work? It will on PC as well?

Anyway good link posted by Cartesius over on renderosity this morning! been using this technique for month now!

P..:

[derwolpertinger]

mdme sadie:
i always put a hue and then a brightness/contrast with the image in the luminance channel. does workin with the fusion to control the saturation of the image provides some advantages? or is it just the same?

[Per-Anders]

absoluetly none! lol, DOH!

hehe, i was just being lazy, and I'd completely forgotten about the HUE control being the lumox that i am sometimes! hehe (i did look for it but for some reason didnt see it right there under my own nose!). Thanks for reminding me... and everyone use BhodiNUT HUE instead of the fusion (unless you want to play around with certain effects you can get that way using different forms of overlay).

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