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View Full Version : HV Presets: "Clouds/Backlit_Cloud" preset-- usage? /thumbnails misleading?



jeric_synergy
11-17-2012, 01:22 PM
Playing around in the sprinkler thread, i thought I'd try various HV volumetric presets.

A standard LW preset is "Backlit_Cloud", whose thumbnail shows a pretty backlit cloud. I figured the backlighting might have been 'built-into' the HV texture, but they just rendered as gray blobs. Adding an actual backlight didn't seem to do anything either.
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So, this makes me wonder: are the thumbnails misleading? Or is it pilot error?

dwburman
11-17-2012, 03:58 PM
It looks about right when I apply HVs to a null and use the preset. I did have to turn the light around.

Maybe it's a scale vs. density/opacity thing.

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Some of the other presets (like some of the fire ones) aren't as easy to get to match the thumbnails.

jeric_synergy
11-17-2012, 06:08 PM
well that's odd: as stated, I specifically put in a backlight just for that purpose. WTH?

jeric_synergy
11-17-2012, 09:07 PM
Here's the scene i'm using, with the unsuccessful backlight. What's different??

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EDIT: still can't figure it out: if you ONLY rotate the original Distant light around, to face the camera, the effect works. BUT no other distant light seems to work, and no other kind of light seems to work.

IOW, in my test, only "Light Number Zero" does the backlit effect. ??????

EDIT2: and now that I've typed that, they've started to work as expected, OF COURSE. 8~ :chicken: :phone_cal

E3: Okay, I can still make it fail pretty easily by adding lights and messing around w/their types, but I can also make it work by adding a new light.

VERY peculiar.

prometheus
11-19-2012, 07:25 AM
Here's the scene i'm using, with the unsuccessful backlight. What's different??

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EDIT: still can't figure it out: if you ONLY rotate the original Distant light around, to face the camera, the effect works. BUT no other distant light seems to work, and no other kind of light seems to work.

IOW, in my test, only "Light Number Zero" does the backlit effect. ??????

EDIT2: and now that I've typed that, they've started to work as expected, OF COURSE. 8~ :chicken: :phone_cal

E3: Okay, I can still make it fail pretty easily by adding lights and messing around w/their types, but I can also make it work by adding a new light.

VERY peculiar.

Presets are very much scene dependent most of the times by nature,lighting,reflections etc..that is one thing you have to understand..I do hope for a FX preset system some day..where you can Bake all attributes in to one fx preset..such as wind effects connected to particles and included
flashlight for explosions etc.

Now for the lighting parts affecting your hvīs, you can control which lights to use in the hvīs shading tab, if you want all lights to affect it, check the use all lights, this might affect your renders to be slower though.
By default hvīs are set to use only the default light.


I will check your scene later.
Michael

jeric_synergy
11-19-2012, 08:20 AM
By default hvīs are set to use only the default light.

I kept looking for a switch/list for such a thing, but never found it. I'll look again.

In particular, I'd like to use multiple backlights of different colors with this effect.

Thanks.

dwburman
11-19-2012, 09:58 AM
I know the Lights to use options are available for Sprite mode HVs, but I don't know if they are there for the other modes.

bazsa73
11-19-2012, 10:39 AM
I kept looking for a switch/list for such a thing, but never found it. I'll look again.

In particular, I'd like to use multiple backlights of different colors with this effect.

Thanks.
On the Hypervoxel panel, under Shading/Advanced tab you can select the light source(s) you want to have an effect on your HVs.
I did a quick test BUT I set the light as spot. Because I have a guess that when it is set to Distant, the position is not taken into conideration only the angle. Maybe I'm wrong but it works for me. Ja, and dont forget to set the illumination method to Rayleigh.
That is the key, Beer model wont produce nice backlight Rayleigh will. But the latter is slower. Set shading quality up to medium at least or more if you want nice effect. And on the hypertexture tab try also different settings.
Cheers

prometheus
11-19-2012, 10:49 AM
yepp use rayleigh,opacity, smoothness and thickness is also important for the right look.

distant lights doesnīt matter about where it is positioned, you use rotation angle for those to direct your light, point lights is usable for position explosion lights or lightning lights inside hv volumes.
a rotation value on the heading channel of 188 degree should be good enough.
Image attached showcase where the tab is, shading/advanced and under illumination method.

Im more concerned that the actual hypertexture nowadays seems to be so off from the presets, I thought they looked more true to presets in 8-9 versions of Lightwave.

Michael

prometheus
11-19-2012, 11:35 AM
Checking your scene jeric, I have no idea of what effect your after though:)

the distant light is useless, since it has no light intensity at all, the dp flood lights works..that is if you activate use all lights in the hv shading/advanced tab.

Michael

prometheus
11-19-2012, 11:43 AM
By the way, regarding emitter nozzle, currently the emitter is spawning particles from obj vertices, this is on the poly chain, but you really donīt need a poly chain as I figure it, just use points, but maybe thatīs more
a visual feedback thing?, however...you can set the nozzle to emitt by object line and then increase particle amount limit and increase birth rate, this will give you more dense emission of particles from that object so
you will have less gaps.

sort of some of my very old emitting tests here...
http://vimeo.com/1745145
http://vimeo.com/2208027

jeric_synergy
11-19-2012, 01:54 PM
Image attached showcase where the tab is, shading/advanced and under illumination method.
Bingo. Now that I know that, everything makes sense! Buried in the tabs, man! Mucho gracias! :thumbsup:

Attached is a 3 light version render, 2 backlights and a red front light.

The weirdness of intensity and emitters was just 'historical': I was experimenting w/other things when I got sidetracked into this, and setting lights at different intensities and whatnot.

Thanks to both basza73 and prometheus for supplying clues to the clueless! :stumped: :jester:
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