Page 1 of 1

Looking for a way to control emitter output via xpresso

Posted: Mon Feb 18, 2019 12:03 am
by Eric Nixon 20170610100005
Hi Marton, I'm stuck..

I need to fade a spot-projection emitter (aka maxwell spotlight) I need to control the materials emitter output from xpresso.

This is for a headlamp comprised of 3 emitters , spot, fill (hidden from cam) and the bulb. For the bulb light i use an omni emitter set to lux, and just control the geometry scale from xpresso. For the fill light I apply a C4D material and control the luminance.

Obviously scaling the spot sphere doesn't help, and I can't make a C4D material autoconvert to a spot.. actually that would be silly because you need to access all the settings + a map to get a good falloff.

It's ironic that its so hard to make feature lights in unbiased engines, For one that fades just need to make it possible..

Could you build a connection?

Re: Looking for a way to control emitter output via xpresso

Posted: Tue Feb 19, 2019 2:16 pm
by Forum Moderator
Hello Eric,

I'm not sure I understand exactly what you are trying to do.

I think I wouldn't use Maxwell spots in this case, as in the case of spots and IES, Maxwell replaces the geometry with a small geometry which size depends on the blur parameter. So, in this case, using luxes is not a good idea as then the intensity will depend on the size of the emitter object, over which you don't have control. I would use area emitters instead and maybe build a hidden to camera cone to create the spot effect.

I hope this helps.

Best,
Fernando

Re: Looking for a way to control emitter output via xpresso

Posted: Tue Feb 19, 2019 9:30 pm
by Eric Nixon 20170610100005
Yes you are understanding, except I don't say anything about lux on the spot., anyhow, as you say there is no way to control the spot from C4D.

But the spot is what I need to use (its around 2x faster).

Btw. C4D r20 is crashing sometimes when I touch the sliders in the material editor dialogue, nasty crash because you lose all your work. Especially common if rolling the mouse wheel over a value.

Re: Looking for a way to control emitter output via xpresso

Posted: Wed Feb 20, 2019 1:57 am
by Eric Nixon 20170610100005
Had that crash again, this time typing into the ND slot of the material editor .

Re: Looking for a way to control emitter output via xpresso

Posted: Wed Feb 20, 2019 7:35 pm
by Eric Nixon 20170610100005
More bugs, c4d crashing on launch render, work lost.

Another bug: The light from omni emitters disappears when motion blur is on.

2nd EDIT: I am still trying to fix this. Its really weird. Up until frame 61 they work on frame 62 left fill disappears, on frame 63 they are both gone. the left object is slightly further ahead in world x, but they have no animation they are just children of the main parent object.

I will try to isolate further. if MB is off all works (same with fire, same with draft)

The scene is having the same problem in mw 3.15 , 3.25, and various versions of cinema..

Re: Looking for a way to control emitter output via xpresso

Posted: Thu Feb 21, 2019 1:24 am
by Eric Nixon 20170610100005
OK is fixed. Problem goes away if there is at least 1 piece of static geometry in the scene, or if you are near the scene origin / within 2ish seconds of start of timeline.. I can't pin those two down.

Re: Looking for a way to control emitter output via xpresso

Posted: Fri Feb 22, 2019 3:03 pm
by Marton Day8
Hello Erik,

Could you please summarize these bugs, a bit difficult to follow.

Are these C4D plugin bugs or Maxwell bugs?

Márton

Re: Looking for a way to control emitter output via xpresso

Posted: Sun Feb 24, 2019 6:18 am
by Eric Nixon 20170610100005
Image

I think its a maxwell bug, If you have one static object then everything works. ( here the grey box is static, camera is tracking the tank ) If not these emitters stop giving light, but its interesting the light furthest from scene origin stopped giving light first, I mean both lights are working until the tank reaches a certain speed, or moves a certain distance, then they turn off.

As you can see the test scene here is tiny, there are no keyframes, as you can see the lights are on but no light comes. I can send this file textures are not needed.

Because a scene normally has at least 1 static object, this bug doesn't really matter does it?