comp.lang.idl-pvwave archive
Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado

Home » Public Forums » archive » Light and images in a IDLgrView
Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend 
Switch to threaded view of this topic Create a new topic Submit Reply
Light and images in a IDLgrView [message #38524] Wed, 17 March 2004 09:44 Go to next message
Antonio Santiago is currently offline  Antonio Santiago
Messages: 201
Registered: February 2004
Senior Member
Hi
i amb using IDL object Graphics and i just have contruct a view with a
volume, a surface, axis and a box. I want to do a slice of axis Y and
view this with an image. I do all this right (and the image have the
slice of the volume in Y axis) but the problem is the orientation of the
model respect the light. Depends on it, the image is visible or is black :(

Is there any tip to tell me how to simplify the work of positioning
lights in a model. The surface is ok iluminatin but images are argggg....

Thanks
Re: Light and images in a IDLgrView [message #38704 is a reply to message #38524] Sun, 21 March 2004 23:29 Go to previous message
Antonio Santiago is currently offline  Antonio Santiago
Messages: 201
Registered: February 2004
Senior Member
Thanks i found my problem.

Yes, i saw your doc and your examples (FSC_SURFACE) but i continued with
my problem. It was basically that i had created my polygons with an
image like a texture map with the bad options and the light doesnt
iluminate it good.


Thanks anyway ;)

David Fanning wrote:
> Antonio Santiago writes:
>
>
>> i amb using IDL object Graphics and i just have contruct a view with a
>> volume, a surface, axis and a box. I want to do a slice of axis Y and
>> view this with an image. I do all this right (and the image have the
>> slice of the volume in Y axis) but the problem is the orientation of the
>> model respect the light. Depends on it, the image is visible or is black :(
>>
>> Is there any tip to tell me how to simplify the work of positioning
>> lights in a model. The surface is ok iluminatin but images are argggg....
>
>
> Support the arts and hire a theater student. They need
> the money and they can have you fixed up in about 2 minutes. :-)
>
> Sometimes it is good to have a set of lights that don't
> rotate with the model and another set that do. See, for
> example, the lights in my FSC_SURFACE program.
>
> Cheers,
>
> David
>
Re: Light and images in a IDLgrView [message #38705 is a reply to message #38524] Sun, 21 March 2004 15:59 Go to previous message
cartik_sharma is currently offline  cartik_sharma
Messages: 4
Registered: March 2004
Junior Member
The following scene graph might resolve your lighting issues:


---->oLightModel
1. oScene-|
|
---->oGeometryModel

In 1., rotating oGeometryModel, leaves oLightModel out of sync!

2.
---->oLightModel
|
oScene-->oModel---|
|
---->oGeometryModel


In 2., rotating oModel, gives oLightModel the same rotation as
oGeometryModel preserving original lighting effects.

Another way to accomplish the same would be to retrieve the relative
transformation b/w the light model and the geometry model, and apply
it to the lightmodel, every time the geometry model is rotated.

Hope this helps,
Cartik

David Fanning <david@dfanning.com> wrote in message news:<MPG.1ac520c216d2805b989704@news.frii.com>...
> Antonio Santiago writes:
>
>> i amb using IDL object Graphics and i just have contruct a view with a
>> volume, a surface, axis and a box. I want to do a slice of axis Y and
>> view this with an image. I do all this right (and the image have the
>> slice of the volume in Y axis) but the problem is the orientation of the
>> model respect the light. Depends on it, the image is visible or is black :(
>>
>> Is there any tip to tell me how to simplify the work of positioning
>> lights in a model. The surface is ok iluminatin but images are argggg....
>
> Support the arts and hire a theater student. They need
> the money and they can have you fixed up in about 2 minutes. :-)
>
> Sometimes it is good to have a set of lights that don't
> rotate with the model and another set that do. See, for
> example, the lights in my FSC_SURFACE program.
>
> Cheers,
>
> David
Re: Light and images in a IDLgrView [message #38715 is a reply to message #38524] Fri, 19 March 2004 14:23 Go to previous message
David Fanning is currently offline  David Fanning
Messages: 11724
Registered: August 2001
Senior Member
Antonio Santiago writes:

> i amb using IDL object Graphics and i just have contruct a view with a
> volume, a surface, axis and a box. I want to do a slice of axis Y and
> view this with an image. I do all this right (and the image have the
> slice of the volume in Y axis) but the problem is the orientation of the
> model respect the light. Depends on it, the image is visible or is black :(
>
> Is there any tip to tell me how to simplify the work of positioning
> lights in a model. The surface is ok iluminatin but images are argggg....

Support the arts and hire a theater student. They need
the money and they can have you fixed up in about 2 minutes. :-)

Sometimes it is good to have a set of lights that don't
rotate with the model and another set that do. See, for
example, the lights in my FSC_SURFACE program.

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting
Coyote's Guide to IDL Programming: http://www.dfanning.com/
  Switch to threaded view of this topic Create a new topic Submit Reply
Previous Topic: STRETCH: A bug?
Next Topic: trying to run IDL from a Servlet using Tomcat 5.0 under OS X

-=] Back to Top [=-
[ Syndicate this forum (XML) ] [ RSS ] [ PDF ]

Current Time: Fri Oct 10 02:41:13 PDT 2025

Total time taken to generate the page: 0.11601 seconds