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View Full Version : Poly Face Cam??



MSherak
10-04-2007, 06:30 PM
It is possible to simulate a FACE CAM for all the polygons of an object through the node editor??

jameswillmott
10-04-2007, 07:13 PM
What's a face cam?

RedBull
10-05-2007, 12:54 AM
The Spot Info node has polyface and normals output, so I'm sure there would be a way to make sure the poly's are always facing the camera somehow...

3DGFXStudios
10-05-2007, 04:55 AM
What's a face cam?


yea what the hack do you mean?

Do you mean the thing you can do with the Advanced Camera? Use an object as cam? or?

MSherak
10-05-2007, 11:26 AM
A Face Cam is where the polygons will face the camera in a spherical fashion..


Example.. If you made a tree with a lot of quads that are not attached to each other.. If you make sure they face the camera at all times it would look like the tree is full with very few polygons..

Here is a link to what it looks like..
http://trees.polas.net/plugins/face2cam.php

Though that is a plugin and was wondering if the same could be done with Nodes

Sensei
10-05-2007, 10:32 PM
Though that is a plugin and was wondering if the same could be done with Nodes

You don't fully understand idea of surface nodes - they are executed for polygon's spot hit by ray.. In other words it's too early to have your effect.. You need plug-in that will be displacing original polygon's points so polygons are properly rotated to camera, prior any ray is casted to the scene..

jameswillmott
10-06-2007, 04:52 AM
That sort of thing should be easily doable as a displacement type plugin, eh Sensei?

Sensei
10-06-2007, 12:32 PM
Sure it's possible to make as displacement plug-in, but it's rather difficult.. Displacements are evaluated for single points, and there is no direct info what polygons have this point - you must scan the all polys and check each their point to compare and assign point to particular poly.. Programmed this way plugin, can be useful (due to highly increasing of slowness) only for simple meshes with max. hundered polys..

RedBull
10-06-2007, 04:49 PM
I used to use a plugin often called FaceCam & Face2Object by Henrik Bengtsson for LW5.x.. Pawel Olas has the commercial Face2Cam plugin more recently.
The link i have for Henriks 5.x plugins are on Marvins site, but it looks like the linked domain is no longer valid.
http://amber.rc.arizona.edu/lw/intro.html

Pawel's version is not supported under LW9 either, and is free if you buy RamdomCloner.
http://www.polas.net/plugins/face2cam.php

Greenlaw
10-06-2007, 10:57 PM
Pawel's version is not supported under LW9 either, and is free if you buy RamdomCloner.
http://www.polas.net/plugins/face2cam.php

FYI, we use Pawel's Face2Camera plug-in quite a bit and it works fine under 9.2. We use it for fast rendering landscape elements (i.e. hundreds of clip-mapped tree and shrubbery 'cards'.) We even used it once to generate huge crowds of people.

I just did a test in 9.3 and Face2Camera seems to work fine in this version as well.

DRG

MSherak
10-09-2007, 10:31 AM
I know there are plugins out there that can do this.. Just wondering if under a displacement node that it could be done.. Sounds like it might be a little more complex since you might have to scan and store data..

gerardstrada
10-10-2007, 04:01 PM
FaceCam (FaceCamera) from 5.0 days still works in 9.3



Gerardo

Ztreem
10-13-2007, 03:57 AM
it's quite easy to do without plugins, not exactly the same way but the result is the same.

Greenlaw
10-13-2007, 11:08 AM
it's quite easy to do without plugins, not exactly the same way but the result is the same.

Please explain.

DRG

gerardstrada
10-13-2007, 04:50 PM
I guess Ztreem may be referring to Follower, Channel Follower or SetDriven Key.



Gerardo

Ztreem
10-14-2007, 02:56 AM
Some quick steps to do this is:

modeler.
1. make a poly for clipmapping facing Z+
2. make points where you want to clone the polyface.

layout.
1. target the polygon to camera and setup all the textures for it.
2. make the pointcloud an emitter and set the number of points in your pointcloud to birth rate and particle limit. Set it to generate by frame and set the life time to 0.
3. use FXLinker to clone your poly object to all the points
4. now you have all your clones facing the camera.

Easy and fast.

Ztreem
10-14-2007, 03:06 AM
Here's a scene to play with, it's only null's but you get the idea. Move the camera and you'll see. :thumbsup:

Greenlaw
10-14-2007, 03:31 PM
I guess Ztreem may be referring to Follower, Channel Follower or SetDriven Key.

Possibly, but as far as I know none of those methods would allow you to rotate individual polygons of an object as if each one had its own pivot point--at least not the way Pawel's plug-in does.

Which reminds me of another advantage to using Pawel's Face2Camera: when setting the pivot of your object's elements (i.e., a tree card), the plug-in allows you to define how many points make up each element, so your element can be made of multiple polygons or ngons. This is a good way to get a little more depth out of your elements as your camera higher up, but it can get tricky if the elements are too complex, and of course this begins to defeat the reason for using the plug-in in the first place.

DRG

Greenlaw
10-14-2007, 03:51 PM
Some quick steps to do this is:

modeler.
1. make a poly for clipmapping facing Z+
2. make points where you want to clone the polyface.

layout.
1. target the polygon to camera and setup all the textures for it.
2. make the pointcloud an emitter and set the number of points in your pointcloud to birth rate and particle limit. Set it to generate by frame and set the life time to 0.
3. use FXLinker to clone your poly object to all the points
4. now you have all your clones facing the camera.

Easy and fast.

I see what you mean, but with FXLinker you're actually working with a scene containing many cloned objects (e.g., your scene has over a hundred objects,) and not a single object with multiple elements.

Pawel's Face2Camera solution is actually much simpler and easier to manage because, for example, you would have only one object representing a hundred cards, which makes a huge difference in managing the Scene Editor or Schematic View. This is especially desireable if the cards are meant to be just one element in a much more complicated scene (and typically I am working with a lot more than just a hundred cards, more like thousands.) When dealing with tight schedules and really complicated scenes, it's always better to keep things as simple and easy to manage as possible, especially if many other artists will be working in your scenes as well.

DRG

Ztreem
10-14-2007, 03:56 PM
You're totaly right, as I said it's not exactly the same solution but the end result is the same in terms that a lot of polys is facing the camera all the time.

Greenlaw
10-14-2007, 04:06 PM
You're totaly right, as I said it's not exactly the same solution but the end result is the same in terms that a lot of polys is facing the camera all the time.

Then again, the solution you proposed is completely free. For most users that's a good argument in its favor. :)

(Face2Camera is only free to registered Random Cloner users so it's not really free.)

Cheers,

DRG

gerardstrada
10-14-2007, 06:40 PM
Possibly, but as far as I know none of those methods would allow you to rotate individual polygons of an object as if each one had its own pivot point--at least not the way Pawel's plug-in does.

Which reminds me of another advantage to using Pawel's Face2Camera: when setting the pivot of your object's elements (i.e., a tree card), the plug-in allows you to define how many points make up each element, so your element can be made of multiple polygons or ngons. This is a good way to get a little more depth out of your elements as your camera higher up, but it can get tricky if the elements are too complex, and of course this begins to defeat the reason for using the plug-in in the first place.

DRG


There's at least a way to do that with Follower, Channel Follower or SetDriven Key. Adding a bone to its respective weightmap for every object's element (VertexPaint can help here). Follower, Channel Follower or SetDriven Key can be added then to bones and all is still a single object. Is not so easy to set up like Face2Camera, but it works (with multiple polygons or ngons too). Maybe is possible to automate the process with an script.



Some quick steps to do this is:

modeler.
1. make a poly for clipmapping facing Z+
2. make points where you want to clone the polyface.

layout.
1. target the polygon to camera and setup all the textures for it.
2. make the pointcloud an emitter and set the number of points in your pointcloud to birth rate and particle limit. Set it to generate by frame and set the life time to 0.
3. use FXLinker to clone your poly object to all the points
4. now you have all your clones facing the camera.

Easy and fast.


Easy and fast Ztreem. I'd add a follower to that setup instead if camera rotates :)



Gerardo