I was trying to create volumetric light beams underwater, but as the picture shows I'm having a problem. The beam didn't want to apear in this pic, but I'm working on another one where I did get a nice beam. But I'm still having this gap. I might upload a better example of my problem later on. In the mean time, any help is apreciated. Rynn.

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On the Vue 4 CD you find an image called "caustics" created by Michael Jansen. Study this image. He has used light gels and light beams under water. A thread for light gels is at the link above. Guitta

I have already spend lots of hours trying to recreate the lightbeams in Michael's picture. I always get those gaps. I included a better picture and marked the gaps, where the lightbeam doesn't show through. As you can see I did manage to get the beams, but with those gaps I can never get a realistic look. Coming to think of it, maybe I can overcome this problem if I put some terrains far away in the distance, to cover the entire background underwater. Cause in front of the terrain the beams are ok. About lightgels the manual says the following: 'You can load any simple material to use as a gel, but only the materials color will be taken into account'. I'm afraid I do not always understand English that well, but for me this seems to say that a light gel gives only a color to the volumetric light. I'm going to play with this a bit more now. Probably till later, and hopefully I got a bit further then. Thank you for your help Guitta. :) Rynn

In case it is to interest to anyone, I managed to get the beams without any gaps. As you can see in the picture ofcourse. You can get the caustics with a black and white bitmap used as light gel. The white is the part that lets through the light. And when you put a terrain immediatly behind your scene then you can get the beams without having the gap. You can also see all these things in the 'caustics' picture that Guitta mentioned before. Ofcourse I had overlooked the terrain, and the fact that the caustics bitmap was black and white. :) Rynn.

Looks good. I haven't done any underwater scenes yet, but I plan to someday and these tips will help.

Fun having a problem, getting some pointers and working your way through the problem and finally getting it right isn't it. :)

'Afternoon Rynn . . . :^) Nice looking light beams. I've tried playing around many times, to get the same type of light beams underwater, but I never succeeded. I'll follow your instructions & see if I can duplicate them. What I don't understand is: 1st, why you have to have a terrain in the background, so the light beams will be solid from top to bottom? 2nd, Why you don't get the same effect by using a "procedural color" caustic, that you do when you use a "mapped picture" caustic, there both images? 8^o Anyway, thanks for the information & you have a good one . . . Mark. ;^)

Very nice, and look how all that effort paid off! I love doing underwater scenes but have not had the "courage" to try one yet! Lyne

Mark, I don't know why you need the terrain, but somehow it seems to make all the difference. As for your second question, I think you can get the same effect with a procedural lightgel as with one created from a bitmap. I believe that it is the colors which are important for creating effects with the gel. For my last example I had used the same bitmap that Michael used in his picture (the one on the Vue cd). That bitmap uses black and white. The black blocks all light and creates the shadows in the volumetric light, the white lets through all light. By using black and white you get a white color for your lightbeams. If for example you use shades of red for your lightgel you will get a red color for your beams. It is ofcourse so that for example a dark red color doesn't block as much light as black does. I hope this is a bit clear. My English is not always that good. I will try to make some sort of tutorial about this that has some example pictures in it. Maybe that explains it better. Rynn.