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View Full Version : digital matte in lw - personal project


gawain
10-15-2004, 01:03 PM
Hi lwers!
I'm workig on some digital matte for a personal project. Here are some sample. All done in lightwave 7; a litte bit ps color correction and noising.
Feel free to criticize, give advice and so on, but please keep in mind that i cannot push realism too far , because of the limited time and resources i can put in this project (i.e. don't be too harsh :))
G.

If the links below don't work properly, just refresh your browswer's window.

http://xoomer.virgilio.it/gawain/gallery/render_hall_low.jpg
http://xoomer.virgilio.it/gawain/gallery/treasure_close_render_low.jpg
http://xoomer.virgilio.it/gawain/gallery/treasure_side_render_low.jpg
http://xoomer.virgilio.it/gawain/gallery/ceiling_render_low.jpg

vonbon
10-15-2004, 01:51 PM
they want show up for me

gawain
10-15-2004, 02:34 PM
they want show up for meSigh. They seem work here... Have you tried to refresh the browser's window?
I'm sorry anyway: maybe here
http://album.foto.virgilio.it/ilmiodragone/717090
G.

LFGabel
10-15-2004, 04:35 PM
if you get a 404 error, just reload the page.

roguenroll
10-15-2004, 04:57 PM
you can drag the link to the address bar, that works for free host sites too. I guess its a direct link thing. ah, computer, weird creatures.

Vertizor
10-15-2004, 05:10 PM
I get a 403 "Forbidden" error.

gawain
10-18-2004, 08:27 AM
Mmmh...it seems this topic is not about my (poor) art anymore but on internet weirdness :sad: .
I will try again: this link seems to work. If doesn't, it's time to buy some hosting.

http://album.foto.virgilio.it/ilmiodragone/717090 (http://album.foto.virgilio.it/ilmiodragone/717090)

Vertizor
10-18-2004, 04:11 PM
The original links are working for me now.


Question for you: are you using Global Illumination at all? I'm having a hard time doing indoor scenes with GI.

Your scene looks good so far. Too much empty space though, but I'm sure that you'll take care of that in due time.

Create a displacement or bump map out of your wall and floor textures and apply them. The walls and floor look too flat, considering the elements (rock and tile) used to construct them.

gawain
10-18-2004, 04:22 PM
thank Vertizor: a critic at last =)

I'm not using GI on the final render; I've applied GI on a small and less detailed model just to study how the light behaves, than tried to reach the same result with multiple spotlights.
I'll try to apply the displacement: i don't know where to start to be honest; just know that the diplacement in lw is pretty weird and so I'm little scared about it. I suppose also that some additional geometry is created and I'm not sure that my steel can handle it ;-)
Can you give me some advice?
G.

Vertizor
10-18-2004, 04:38 PM
Bump map it then. Bump maps affect the way the texture looks, creating depth in the pixels, without changing geometry. Displacement map might just be overkill for a simple effect.

A quick and easy way to do this is just open your texture in Photoshop and "desaturate" it (removes all color and gives you a grey scale version). You can use the Levels tool or brightness/contrast tools to adjust the grey levels. Then setup the bump map channel exactly like your color channel (tiling, size, transform, etc.) except use this new bump map image instead of the color image.

gawain
10-18-2004, 04:49 PM
Thanx,
pillars and floor and anything is quite heavy bumpmapped with grayscale-hard contrast maps, but the effect is not very highlighted when the mesh is not well...highligted ;-)
If you render the pillars with a quite near camera it is more noticeable... Anyway: the fact you didn't notice the bump is because the overall effect is too flat... I'll work on this...maybe jittering a little bit the geometry
G

Vertizor
10-18-2004, 05:57 PM
I did a test a while ago with displacement maps (can't for the life of me find the rendered images now). Displacements are obviously more visible than bumps, but a combination of both (especially with stone walls) would give nice results. Of course it killed my viewport performance but I just positioned the camera first, then modeled the structure afterwards. You can also switch your viewport to "bounding box" mode for performance sake while you get the camera into position.

The problem with the corners of the walls and edges of the pillars is that they're too square, the edges and corners are too sharp. It makes everything look like wall paper, and bump mapping only makes the flat area less flat. Bump mapping won't save us from the sharp corners. Everyone will tell you to bevel your edges, but IMHO that's not going to help much here, these are stone walls.

Ultimately I think you're better off with displacement maps. Just use bumps for the time being to help you set up your scene. Worry about bringing it to [more] real life later on. Your render times most likely will shoot upwards with the additional geometry.

gawain
10-19-2004, 09:55 AM
I did some experiments with displacement and, because it is the first time i use it, got some odd results. I will search for some tutorial.
Can you suggest me a straight forward way to implement the displacement?
Anyway: it is for a matte, so i can add details and adjust pillars profile with photoshop...

thanx for support!

Vertizor
10-19-2004, 03:36 PM
I don't have LW in front of me right now, but in the material editor there's a channel for displacement map correct? You just provide it with a grey scale image to use as displacement, just like bump maps. There should be controls to restrain the min/max displacement depths. Last time I played with displacements was in Cinema 4D so bare with me, and sorry for the lack of specifics. But basically that's all there is to it.

BUT the most important step is to sub divide your model... many many many times. Displacement operates on vertices (bump maps operate on texture pixels) so you will need a lot of vertices to get the same resolution of your displacement map. If it doesn't look right then you need to tweak the displacement settings in the material editor. But if you think those settings are adequate then you probably need to subdiv your mesh a few more times to add more vertices. Switch to bounding box or wireframe before you do this though.

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