can C4D use accurate light intensities?

[jackb602]

Hi all,

 

I've been working my way through the C4D tutorials with the demo version of R8, and I have a couple of questions. Basically I've been trying to master radiosity in FormZ for a while now, so that I can do all my work in one app, but radiosity is partciularly hard to master. Cinema 4D seems to produce some great renderings, and from the tutorials I've found on the web, their GI system (photon mapping I assume?) seems much easier to learn and control. However, FormZ has a couple of important features I'd hate to give up. Two of these are accurate light intensities and post-rendering exposure correction.

 

Does Cinema 4D support accurate light intensities (i.e. in lumens, watts, etc.)? So far, I've only seen 0-100 "brightness" sliders.

 

Can it produce false color renderings showing real light intensities in a space? For example, if I want to know the illuminance of a desktop in an office space, can C4D accurately determine this?

 

Finally, does C4D allow me to correct exposure for an image once it's rendered? For example, I'm modelling a large (7000 sf) space with windows at only one end, so there is a huge range of brightness from sunlit areas to the furthest corners. FormZ lets me boost the perceived brightness of the shadowy areas, so that they are visible.

 

I know these are a lot of questions, but before I take the leap and spend lots of money on C4D, I'd like to know a little more about what I'm getting in to. Thanks,

 

Jack

[Paul Griger]

Hi Jack,

 

Originally posted by jackb602:

I've been working my way through the C4D tutorials with the demo version of R8, and I have a couple of questions.

Does Cinema 4D support accurate light intensities (i.e. in lumens, watts, etc.)? So far, I've only seen 0-100 "brightness" sliders.

AFAIK, no

 

Can it produce false color renderings showing real light intensities in a space?

Again AFAIK, no

 

Finally, does C4D allow me to correct exposure for an image once it's rendered?

Well, C4D can output your final rendering to the Adobe Photoshop layered/multipass format, and then you can make adjustments there. So for instance you can assign within C4D each light to be on a separate layer in a PSD file. You can then take that farther and assign to each light up to three different layers for three respective properties of a light’s effect, diffuse, shadow and specular. And other scene items besides lights can be assigned to separate layers within C4D when outputting to a PSD file. These items can all be assigned to separate layers within C4D for output to PS:

 

Ambient, diffuse, specular, shadow, reflection, transparency, radiosity, caustics, and atmosphere. Plus you can blend any of these layers together before outputting them to PS.

 

Can the demo do multipass outputs? I’ve never tried it.

 

Strat may know about this than I do and he may chime in here. Otherwise, I’d post this over at CG Talk, there some guys there that live and breathe C4D and have tried many other programs and may be better suited to answer your Q than myself or if Strat doesn’t chime in soon enough for you.

 

http://www.cgtalk.com/forumdisplay.php?s=&forumid=47

 

BTW, I think C4D uses the Monte Carlo calculating system rather than photon mapping for GI calcs, but I could just be mixing up terms here. C4D can also use Stochastic rendering to figure out radiosity; it’s really slooow, but supposed to give accurate GI calcs, and this method can show a little graininess in the final rendering.

 

Best,

 

Paul

[STRAT]

jack - paul answered ur question there.

 

by the sounds of it you want lightscape, that radiosiates the light strength values you require.

[jackb602]

Thanks for your detailed reply Paul. It sounds like C4D can't use accurate photometric units. I hope that appears in a future version.

 

The demo does offer multipass rendering (I think it has all the features except that it cannot save). That's a feature I'm really interested in, but it only would be helpful for a scene with multiple light sources. I'm more concerned with a single sun and/or sky light. I think I'll have to play around with the demo some more to see what results I get.

 

I'll try posting in the CGtalk forums as well, but I've found a lot of useful information here. I think I'll probably end up going with Cinema 4D for rendering, but I'll have to budget for that. Thanks again for your help,

Jack