View Full Version : Problems with image maps

05-08-2003, 10:04 AM
Ok, here is my problem, it is multiple problems that involve Aura and Lightwave, so please excuse this post if you already read it in the Aura forum. I am using Lightwave 6.5b on Win2k

Ist Problem:

A long time ago on the old forum someone posted a movie of them going up in a puff of smoke. Well, last weekend I was playing around trying to do the effect. What I did is took some video footage of the room, then had a person walk in and recorded it too. Edited the video in Aura so I had 2 equal lengths of film. One was with no person, one was with another person sitting down.

Next I took the video of the person sitting and roughly cut the the surround video away leaving the surrounding black. So basicly now I have a person floating in a sea of black, and since I didn't go right to the edge, he has an outline aroudn him. I did not crop the image or anything.

Then I opened up modeler and then loaded the image of the person in the sea of black and made a polygon outline of the person, not including the extra stuff around him.

Now I load up Layout, set the back drop to the video plate of just the room. I then tried to do the camera mapping tutorial in the tutorial section of Newtek. That got me know where. So I loaded my polygon model of the person. Then opened surface editor and placed the avi file of the person onto the object as an image map. But when I move the polygon model the image doesn't move with it! It's like I can't get the image map to clue to the surface of the model.

2nd Problem

Once I can find away to get the image map glued to the model, I want to "blow" the model up so that I get a mess of little pieces. What plugin - script is out there that disconnects polygons?? I tried crack-it, but it can't handle a flat plane. I thought Modeler had something that let me do it by hand?? Ohh.. you know what, I never thought about cutting and then pasting the polygons backinto the same layer... Once I get the above to problems solved, I am all set.. almost

3rd Problem

How can I render an object without the object being htere, but still affect the scene?? One of the things I tried to do take 2 particle emitters and cirlced them around my object with the image map and made it look like smoke was forming around him as the particle cloud rose. What I wanted to do is turn off the object with the image map and when it rendered have the particles hidden when it was behind the object and visible when they weren't behind the object. But when I rendered it (I set the object to unseen by camera), you could see the particles like the object wasn't there. Is there anyway to do this??

4th problem

This is the part that deals with aura and lightwave. Using the above scenario, I was going to composite the images of the smoke over the video I had. Since I couldn't do that, so I used my object with the image map and particles, rendered and saved the RGB channel and the Alpha channel as Targas. I also turned off my backdrop before I rendered. Opened Aura, loaded my clean plate into a layer, then loaded my object with map alpha map targa (I did 3 sets of renderings, one with just particles, one with just objects and one with object and particles) but it was like there was no alpha channel!! the video shown as just a black and white object. I switched the layer orders around and all I got was my avi plate. I tried all the others and got the same deal.

So tell me this, is aura not capable of doing this?? Must I get Adobe Aftereffects??? I couldn't find anywhere a way to set the image to an alpha channel. Did I render the images out wrong? I did it once before by accident on an animation. The background was set to blue and when I opened it into aura it removed the blue background and left it back. It was neat cause I could put anyhting I wanted back there. I just don't know what I did to make it happen.

Which makes me think... maybe I should have rendered the sequences with a backdrop color instead of a black backdrop.

Anyway, I hope there is a way to do all that I have listed.

Thanks ahead of time.

05-08-2003, 02:10 PM
Your fourth problem is the easiest to solve I think. Save your images as Targa32. If you've turned off your backdrop and set the backdropcolor to 0 0 0 the alphachannel is imbedded in the targa's. Aura will load them will load them with proper opacity. You don't need to render separate alpha's.

05-08-2003, 02:52 PM
Woohoo... #4 down, 1-3 to go!!

Thanks Baba!:D

05-08-2003, 03:05 PM
Okay. I'm going to try to help, but bear with me because: a) I'm at work and 2) I don't have Lightwave here to see what the panel names, etc. are.

1. Actually this is probably going to be the hardest to explain. I believe in the texture editing window for color, there is a simple button you press to get the image to stay with the camera. It may also be in the camera panels. I forgot exactly what the tab says, but I'll check when I get home.

2. The best way would probably be to cut it up yourself, like you've figured out already. I'm sure there are mroe plugins that would do it besides crack-it. Check at flay.com. You could use CGExplosion (available at flay.com) to blow it up.

3. Okay. Make this so it can be seen by the camera. In the texture properties (yes, you have to set it for all of the textures on the plane, but it sound like there is just one, since you are front mapping the video to it) it's the second tab in. I forgot what it's called. I think it's the top-most option. Check through the options. I think they are self-explanatory, but the one you want should be there.

4. I have never used Aura.

I hope this helped although it was VERY vague.


05-09-2003, 02:26 AM
2. subdivide your object using knife or what ever tool you prefer then Unweld polygons (ctrl U), now you can move each polygon individually, you could use morph mixer tu animate the pieces exploding out, but there are several pluggins that would make a more natural explosion.

05-09-2003, 07:33 AM
Ok, definetly got 2 and 4 down. 1 and 3 are still a bit shady to me.

Thanks for the help so far!!

05-09-2003, 12:25 PM
Okay minifiredragon,

At work again, (gotta check this forum when I'm home), but for number 1...Open the texture editor. You should have mapped the image using T for color settings. Choose front projection for the mapping and then pick the image or movie that is going to be projected onto the plane. In this same window, the one where you chose front image mapping, click ON a tab for "Fixed Projection." Now the projection will stay on the plane if you move it.

I'll have to get back to you from home about #3.


05-10-2003, 11:13 AM
OK. I'm home now. For the answer to number 3. In the Surface Editor, the second tab in is Advanced. The first option is Alpha Channel with a pull-down menu. With the surface for the plane, change Alpha Channel to Constant Value. Make this value 0 (zero). This will make it black, and therefore invisible when compositing comes along. It'll make it so you can not see things behind the plane when you composite. I just tested it. I believe that was what you were looking for.


05-10-2003, 01:13 PM
OK, 1, 2 and 4 are solved. Marvin, I tried your number 3, but it still rendered the object. I even turned off the texture to see if it works. So all I see now is a white object. Maybe u missed a setting??

Thanks for the help so far!! One more to go unfortunately.

05-10-2003, 01:46 PM
#3: Turn on Matte Object (this is LW 7.5)
Object Properties -> Render -> Matte Object


05-10-2003, 01:58 PM
C4 is one of the better free plugins for blowing stuff up. I have used both CGExplosion and C4 and I recomend C4 anyday.

Thats 2 done too.

05-11-2003, 11:18 AM

It does still render the object with that texture on it, but if you check out the alpha channel for that render, the plane with that texture is not in the alpha. This works if you are going to composite out of LW, such as in After effects.

You could also try LightWolf's idea, although I didn't even know that was a new feature in 7.5. It seems the easiest.


05-11-2003, 08:03 PM
Wohoo!! Thank Folks!! All problems have been solved. Thanks so much for the help. And I hope to get 7.5 soon.