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IronGoblin
10-08-2004, 08:49 AM
Howdy.

Gonna apply on a 3dposition at a company working with rocks and stuff (geology might be the correct word..?) Anyways... thought I whip together a few samples in that field.... So i started out with a lavastream.. Using particlefx and hypervoxels... its a viper preview..

Appreciate it if you take time to give me feedback on this one, since i havent done lava before.

Here goes.. (hope the link works):
http://www.firestorm3d.com/flics/lavastream03.avi

Keep on truckin'

Spacemanbob
10-08-2004, 01:48 PM
WHat codec are you using. I get an error viewing it in Mediaplayer.

angel
10-08-2004, 02:08 PM
I've never done lava before but I can give you a couple of suggestions; the mountain side is too dark, at first I thought I was looking at a space scene. The lava is probably too blobby, maybe adding more particles will help to enhance the effect...

IronGoblin
10-08-2004, 05:35 PM
Spacemanbob: i believe its divx.. versionnumber something.. :)

SNoWs: good point. Ill lighten the scene a bit. I did try to add more particles, but i had some problems with them jittering all around because of self interaction. But ill try to add some more, and maybe adjust the settings a bit.

thnx for the feedback..

Keep on truckin'

angel
10-08-2004, 05:39 PM
try with multiple emitters and have them blend in a group and see if that helps.

IronGoblin
10-09-2004, 07:10 AM
Howdy.

Did another preview. Added another particlesystem, made my hv's a tad smaller. made everything a bit brighter. (Still crappy background... :D)

Anyone know how i can make the texture of my hypervoxels rotate along the movement of the particle?

here's the link:
http://www.firestorm3d.com/flics/lavastream04.avi

keep on truckin'

Triple G
10-09-2004, 12:34 PM
What are you using as reference for this? Good reference material can make all the difference. I think we all pretty much have a general idea of what lava flows look like, but it's not something most of us see every day, so it's hard (for me anyway) to give specific critiques. I think your HVs are still too blobby, which is not an easy thing to avoid. Try adding a stretch value based on velocity...that might help. Increasing the particle count and/or size may help too, but obviously you need to be careful with render times. I'd say maybe adding a secondary emitter which spews out some drifting smoke or steam would look cool and might help to tie everything together...again, it's tough to say though without knowing the exact look you're going for.

I don't know how realistic you want to get this, but a shadow from the lava being cast on the ground would definitely help. Since raytracing shadows of HVs takes FOREVER, here's a technique which I've found useful:

1) Create a spotlight to cast your shadows, and position it accordingly. Make sure that the cone angle completely encompasses your scene...you want to make sure that anything you see through your scene camera will be covered by this light.
2) Create a new camera (call it Shadow_Cam or something similar) and parent it to the light. Look through the camera view and adjust its zoom factor so that the camera's field of view matches the cone angle of your light. This is easy to do if you have two views, one set to Light View and the other to Camera View.
3) Set all objects in your scene to render as black matte objects, and have them be Unseen by Alpha.
4) Render your HVs through your Shadow Cam. I usually double or triple the resolution of my scene camera (depending on the scene), since it's usually pretty far away and the HVs don't fill most of the frame. Render with minimal antialiasing settings (if any at all), and turn off volumetric antialiasing...you won't need it. Save your alpha images (these are all you need, the RGB is not necessary) as an image sequence.
5) Save a copy of your landscape with a new surface. Make its RGB value 0,0,0 with 100% diffuse, and everything else set to 0%.
6) Now, load up the image sequence you just rendered, and go to your spotlight properties and tell it to use this as a projection sequence.
7) Render through your scene camera, which will go super quick, and you now have a shadow pass for your HVs which you can composite in something like After Effects or Fusion. (Your images will be white on black, so you'll want to use them as a luma matte for a solid layer).

It seems like a lot of extra work, but I've found that in many situations doing these extra few steps is actually quicker than turning on raytraced shadows for your HVs. Plus it gives you a lot more control over the final look.

Anyway....sorry for being so long-winded...maybe this will help you, maybe it won't.
:wip:

roguenroll
10-09-2004, 09:48 PM
hahapretty cool, its running a little fast, but considering this minor problem, you have some really convincing lava, also might add some smoke puffs from various points.

maybe you could animate the texure a little.

good one:thumbsup:

CLAW
10-10-2004, 02:35 PM
hmm, don't know.. looks very metaball, voxels whatever. You need to paint a underlying texture so it looks like the lava is staying on the rocks.. else it will looks kinda odd.

good start though!

Jimzip
10-11-2004, 05:41 AM
It's a really nice lava texture, first of all, but I think the texture would suit a still picture more.
The black parts of lava are the bits that cool down and then stay generally where they are, or get carried along with the flow but on top of the hotter still-flowing lava underneath. Maybe adding a reference null to the black part of the texture, and making that null move along with the flow, but slower might add a more realistic effect.. Ah HyperVoxels are such a pain to get right. I try to avoid them at all costs..
Also the other suggestions here I agree with, maybe a few more particles, the shadows, even though you may pay for it with your soul..
Good luck!

Jimzip :D

IronGoblin
10-11-2004, 02:00 PM
Whoa.. thnx for all the feedback. Sorry for the slow reply, but i've been away over the weekend.

Triple G: Ill try out your shadowing method for the smoke, cause its really really slow at it is.
Claw: how do you suggest i paint an underlying texture...? I mean.. it would have to appear where the lava is.?
JimZip: currently its only a bumpmap with a gradient set on color and luminosity... So i guess i would have to do some serious alphamapsettings to get it to move a bit slower than the lava.. but ill try to have a look at it..
roguenroll: thnx... i tried adding smoke.. (put it on a render over the weekend)....

I made a new particlesystem for the smoke.. added hypervoxels and a windsystem.. then i took my initial lavaparticlesystems.. redused the amount of particles.. and used fx linker to attach the smokesystems to the remaining lavaparticles.. and then i rendered out the smoke.. Any other way to do this?

So here is the weekendrender.. lava and smoke rendered apart.. compositet in aftereffects.... Smoke looks weird.. anyone have any suggestions on how i could make it look like it appears like coming from the lava?

http://www.firestorm3d.com/flics/smokeandlava.avi

keep on truckin'

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