I am doing some tests with volumertic surfaces, lights, and atmospheres.

In using Lightwave spotlights, I have a setting for the starting conical point for the light beam. Looking through the VUE manual and settings for lights, there are only a few settings. They affect the the lights throw, angle, intensity, and color. I need to remove the conical peak. But once I place the light deeper in the model, the light ceases to function. Currently I am using a point light at the spotlights base, but that is more a hack and is not going to do the trick.

Anyone know where that setting would be?

Thanks in Advance

Rich

Hi Rich, As far as I knew when I started writing this there wasn't a setting in V5I that can truncate the cone of a spotlight and get the volumetric effect to show after it passes through another object. Now I've found two ways each of which has advantages and disadvantages. The only I'd found of achieving the effect you want before this morning is to place the light source within the object. As you say this causes the light not to show as it doesn't shine through. To get it to appear you will need to modify the object the lights are inside. I've done this a couple of ways in the past and the method used varies depending on the scene. The first and possibly easiest method is to cut a space into the model for the spotlight. Either model the object with the hole to start with or place a primitive and use a boolean operation to cut the hole. If the light needs to shine from behind a solid then I'd cover the resulting hole with another primitive with a transparent material applied with reasonably high global transparancy. To accentuate the volumetric effect sometimes a better result can be had by stacking several identical lights on the same spot rather than cranking up the settings on one light. A similar result can be achieved by making a transparancy map for the object with the holes made by using transparancy. Playing around this morning I've found that it is possible now to create a truncated cone in V5I. Select your spotlight. Right click on power and then select the lighting tab. Right click on the graph and click "edit fileter". The graph editor should appear. Create two new key points and drag them to make a graph like the one in the image above. This should give you a truncated cone. In order to get this to shine past an object go to the shadows tab and turn off shadows or turn them down with the slider. This lets the light's volumetric effect appear past objects in the way. Cheers Mark

Very interesting Impish. Filed that one for the future. Belongs in the "Backroom" :o)

Fantastic impish! I would have never thought to try a filter setting for that. I'll give it a try and see how it goes. Thanks very much. Rich

Hi Rich,

Your question just kicked off something I'd tried and failled to get V4Pro to do. It was fun to look at it again and find V5I can do what I was trying to do before. I've just found one last refinement that may help. If you don't mind the object the light appears to shine from not casting shadows but you want the light to cast shadows after it you can edit its material settings in the advanced material editor. Turn off the option "cast shadows" for the objects material. This way you can have the light cast shadows still.

The red box in the picture has it's material set not to cast shadows while the blue ball is set to cast shadows.

Hopefully that makes sense but after a long day at work it may be just so much incoherent bable. Cheers Mark

Message edited on: 09/05/2005 16:05

useful findings there Impish cheers