light gels/shadow masks - failure

[Ernest Burden III]

Close, but not a success.

 

I was attempting to improve on regular C4D lights, since we don't have IES lights (yet?). I tried using a gel (material on the light with a trans channel only) This works, sorta, but the map size is hard to control (via mapping texture controls) and it projects parallel, not radiant like a light.

 

I tried using a poly placed over the light to cast the shadow and did get the radiant, but the light is brighter farther away than closer. No good.

 

The first image is a gel, fun but not much practical use.

 

The second has several lights with my mapped poly shadow-mask, with the rightmost light being a regular gel light.

 

So close.

[Tim Nelson]

If I lived in the 60's the first image might be quite nostalgic! Is that a butterfly pattern I see?

 

The second image looks close, but I'm surprised that a modern renderer like c4d can't do ies lights. For such a supposedly simple renderer, it does seem to pose quite a few challenges. Have you looked at Fran's idea to use a projector map in a standard light to simulate ies lights? I'm not familiar with c4d at all other than what I read from other users here so I don't even know if thats a possibilty or not.

[STRAT]

i guess it just needs more refinement and tweeking m8. an IES plugin would be great.

[3dp]

as a non cinema user

max/vis lights allow the attachment of a bitmap to act as the get

indded i bought one of the very first copies of dosch lightscenes as it had lots of rigs and vlume light settings for those stage sets and theater visuals that sadly i've never managed to berak into..................

anyway as you are a lightscape user you've probly got a shed load ies files around but the really intresting fittings from compaies such as zumbotel with the parabolic reflectors....................they don't have files per se so you end up faking them and then it comes back to artistic flair

in the past when i used lightscape as a analitical (sphellings?) tool more than a presentation piece it would still be a "representation" to check 300lux at floor plane etc and if you could get some nice images thats nice too

 

ies files do not take into account factors such as light diffraction from a dichroic fitting or that green hue from a stock flourescent once you get otside of lightscape it's all manual input and rerender testing

so really you're not missing much just now and doing what you're doing with virtual gels looks fine and better than most

it's like many things these days will a client notice or even care...........having worked with accutate laighting tools for nearly 10 years i'd say no unless it's going to court

feeeeel as bruce lee once said seems to be the main issue

[Ernest Burden III]

If I lived in the 60's the first image might be quite nostalgic! Is that a butterfly pattern I see?

 

The second image looks close, but I'm surprised that a modern renderer like c4d can't do ies lights...Have you looked at Fran's idea to use a projector map in a standard light to simulate ies lights?

 

Guys! Using a map in a light is where I started, that didn't work right (see rightmost light in test) and I went to a map just in front of the light, which failed for other reasons.

 

IES lights would be a treat, I didn't use 'em much in Lightscape but now I miss 'em.

 

Strat: I don't see what else to do to refine my idea. If you have any ideas, it would be great (for all of us). If you want my test file I'll email it to you. You can see what I'm trying to do, it just doesn't quite work.

 

 

60's, yeah, I survived the 60's as a kid in San Francisco with hippie parents. No nostalgia for me. Yes, those are butterflies, just the standard Photoshop brush.

[STRAT]

the only time i use a projector map is for caustics.

 

i've never yearned after ies lights personally, but perhaps when i get the time i'll try out some of the techniques you talk about.

 

by the sounds of it a gradiented alpha map masked over the light is the most logical way to go.

[Ernest Burden III]

i've never yearned after ies lights personally...

by the sounds of it a gradiented alpha map masked over the light is the most logical way to go.

 

IES allows for a shaped light output, including varied power. For example, you could make a light that shines a ring of light, or brighter on one side than the other, or both. They take longer to render, but when needed look spectacular.

 

The map over a light just doesn't seem to behave like a real light, so I admit defeat.

[edub]

sorry to resurrect this thread, but I was hoping for some new developments in methods for faking IES lights in C4D.

 

I thought I had seen such a thread more recently, but this is the only one that came up, specific to C4D.

 

I'm not sure I even understand the methods described in the first post; how does one apply a shadow mask to a light in the first place?