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Johnny
06-15-2005, 03:23 PM
I have an object whose surface includes a gradient that changes from the front of the object to its rear. I have this mostly working using Distance From and a null (distance from null).

the null is parent to my object, so that where the null moves, so does the object. Yet when the null/object are far away, you can't see this gradient surface; you can see it when both are near the camera. I need that surface to behave constantly, and I'm not seeing why it doesn't based on the fact that I'm using a null to control it.

I've tried using Distance from pivot point but that gets me nowhere (I position the object's pivot point right where the null is placed in another file using the same object.

Any ideas on what I'm missing?

thank you!

Johnny

Hoopti
06-15-2005, 08:59 PM
You mentioned you're parenting the null to the object, and then when you move the null the texture changes. I think you've got your parenting backwards.

Hoop

Johnny
06-15-2005, 09:02 PM
You mentioned you're parenting the null to the object, and then when you move the null the texture changes. I think you've got your parenting backwards.

Hoop


sorry..I might have written it wrong; the null is the parent, the object with the gradient is the child, and the child's surface uses a gradient which incorporates Distance from Object, which in this case is the null.

J

Surrealist.
06-15-2005, 10:23 PM
Try this thread and see if you get some ideas.

http://vbulletin.newtek.com/showthread.php?t=37578&highlight=gradient

If not post a pic of your object and lets take a look.

Hoopti
06-16-2005, 10:36 PM
Here's a scenefile with a box parented to a null, using a distance to object gradient, with the null moving, and the gradient remaining the same. I'm not able to duplicate your problem. Let me know where my assumptions are wrong and I'll try to help.

The movie of this scene is here:

http://www.bigdogvideos.com/gradientbox.mov

Hope this helps.

Hoop

Johnny
06-17-2005, 06:48 AM
Hope this helps.

Hoop


yeah, actually it does...now, after coffee, I'm going to take some screenshots and do a few renders to show the problem I'm having...

hope it's something dumb, or something I forgot TO do...

thanks for the help..pics to follow shortly.

Johnny

Johnny
06-17-2005, 12:26 PM
Sorry it took so long..got sidetracked.

OK..the 3 images on the right are from a quick clip, far, closer, close up. "Far" is not meters away, but inches. Close up is pretty much right in front of the camera.

Top left image shows the XYZ arrows of the null which is parent to the bolt.

Bottom left image shows the relevant part of the surface showing the gradient, and how it's used in distance to bolt null. 50mm is where I want the glow to end; the bolt overall is about 60mm.

now, to me, the top right image barely shows this white-hot metal..you get a little brighter in the middle image, and brightest in the bottom. Even tho red hot metal appears less bright with distance, it shouldn't be AS dull as what's pictured above.

J

http://www.bluemitten.com/bolt.jpg

toby
06-17-2005, 02:32 PM
It just looks like it's getting darker - is it moving away from your lights ( are they set to falloff?) or do you have fog on - to make sure if it's the gradient or not, replace it with a white texture or something and see if that fades

Johnny
06-17-2005, 02:35 PM
It just looks like it's getting darker - is it moving away from your lights ( are they set to falloff?) or do you have fog on - to make sure if it's the gradient or not, replace it with a white texture or something and see if that fades

that's how it looks to me, too... no fog at all..I'll try your suggestion to test whether the gradient or not...and will look at the light falloff angle...right now, I don't recall if they're set to fall off...

*EDIT* D'OH! just hopped back into the scene, turned off the light fall off on the 2 lights, and scrubbed with fPrime on...that was it!

I feel both relief and embarassment...at least I learned something...thank you!

J

Hoopti
06-18-2005, 05:51 AM
Glad it worked out.

Hoop

toby
06-18-2005, 03:21 PM
You know what would look totally bitchin' on that rivet? Some fake sss using the distance-to-light (or object) gradient in the luminosity channel.

discussed here -
http://vbulletin.newtek.com/showthread.php?p=241143&highlight=SSS#post241143

Johnny
06-19-2005, 08:52 AM
You know what would look totally bitchin' on that rivet? Some fake sss using the distance-to-light (or object) gradient in the luminosity channel.

discussed here -
http://vbulletin.newtek.com/showthread.php?p=241143&highlight=SSS#post241143

yeah, that WOULD look cool! I guess 'sss' stands for sub-surface scatter...

J