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WesM
09-03-2003, 07:07 AM
Hello,

I am having some problems with texturing. I have this plastic piece in an object and I want to add scratches and dirty it up. I'm not sure how to do this. I have seen renders with finger prints on glass and scratches. I really want to strive for that kind of realism. I tried applying a scratches image map to the diffuse channel, but I'm not getting good results. Can anyone share some techniques on how to grunge up an object?

Thanks a lot,

Wes

WesM
09-03-2003, 09:26 AM
Hey Guys,

I have been trying to get some grime onto my objects. Here is a test image. One thing that I have trouble with is reflections. I notice that when I use reflection maps, they tend to give off the affect of leaving ambient intensity up. I need to find a work around this. On my object I am using a reflection spherical map with a gradient controlling the incident angle. I balanced the reflection setting with my diffuse value. I have the reflection value turned down, but it's lighting the side of my object too much, giving a flat shade. I have one spotlite in this scene and ambient intensity is turned down to 0%. How can I fix my reflections so they are not flat shading my objects?

Thanks,

Wes

WesM
09-03-2003, 09:28 AM
Sorry I didn't attach the jpeg image in my last post.
It doesn't seem to be attaching to the post.

Triple G
09-03-2003, 11:19 AM
This is a problem with Lightwave's reflections...as I understand it, they're always treated as additive. This is fine in some cases, but in others (like yours), the reflections are too bright and look unnatural.

One way to fix this would be to render a separate reflections pass and then comp it in post. Or, you could remove the reflection map and use actual objects and raytraced reflections, which would give you more control over where your reflections show up. There was a nice tutorial that I remember seeing (of course I can't find it now :rolleyes: ) which showed you how to precisely control where parts of your reflection map would show up on your object when rendered. Hopefully someone knows what I'm talking about and will be able to provide a link.

One other solution would be to check out Hypersmooth (http://www.evasion3d.com/hs_intro.html), which gives you a lot more options in your rendering of reflections.

fxnut
09-03-2003, 12:10 PM
Hi Wes,

It sounds like you just need to do an occlusion pass. Have a look at this old thread I posted a while ago here (http://vbulletin.newtek.com/showthread.php?s=&threadid=5123). In my second post to that thread I mention the occlusion pass.

Basically, all the occlusion pass does is mask out any areas that the reflections wouldn't occur. It's necessary because reflection maps don't take into account the object's geometry getting in the way of the reflection. By applying the occlusion pass, it'll get rid of the "boosted ambient" appearance that is concerning you.

If you follow the links on that thread to my website, you'll be able to download an animation showing each pass (including occlusion) so you can see what it looks like.

Regards

Andy

munky
09-03-2003, 01:24 PM
A really good trick is to use a specular map, even some noise in the specular channel to break up the highlights is a big help.

regards

paul

WesM
09-03-2003, 01:31 PM
Hey Everyone,

Thanks a lot for all of the advice. I really appreciate it.
I have a lot to work with now, hopefully I'll get it right.

Thanks,

Wes

munky
09-03-2003, 01:37 PM
Oh Wes one more thing. If you go to www.dvgarage.com and register (it's free and they don't sell your details on ) there are a shed load of tutorials all about surfacing as quicktime movies and some will be exactly what you are looking for.


regards

paul

fxnut
09-03-2003, 02:11 PM
Yeah, a good site that one Munky. In fact, what Wes is working on seems almost identical to one of the tutorials that I remember seeing there a while ago, so I reckon he'll not have any problems applying it to his project.

Regards

Andy

toby
09-04-2003, 10:17 PM
Great thing in LW for adding dirt is Surface Mixer, under the 'Shaders' tab.

You no longer need to add dirt characteristics into every channel of your plastic surface. Bring a 'dirt' polygon into the scene, add 'surf mixer' to the plastic surface, set blend surface to the dirt poly and blend opacity to 0, then add maps.

WesM
09-05-2003, 07:14 AM
HI,

Thanks again guys for the advice. I have been checking out the DVgarage site. I'm learning alot from their tutorials. Thanks.

Hey Toby, in your post you mentioned Surface Mixer. I have never heard of that tool before. I checked under the shaders tab and didn't see it. What version of Lightwave are you running under? I checked under version 7.0. It sounds like a cool tool. Thanks for the tip.

Thanks,

Wes

toby
09-05-2003, 10:25 AM
It was new in 7.5b, or c for us Mac users. It's a free upgrade