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I have been experimenting with RW and Rad for rendering light Q's for stage productions. It seems that the time to render with Rad isn't worth it as I like RW rendering better.

Maybe it is because I don't understand Rad but these are an example of a Q rendered. RW took about 45 SECONDS and Rad took 1 1/2 hours.

Some input, suggestions, and your thoughts about this are welcomed.

Jim

First photo is RW and second is Rad 145049169_f97f633f5b.jpg?v=0

145049168

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  • Vectorworks, Inc Employee

Hello Jim:

Looks like the ambient is set too high. Try turning it off for the radiosity rendering.

Also, I don't know if what you're trying to see is the indirect lighting on the person or on the walls. If you are trying to get indirect lighting on the walls, the Init Detail can be in the range of several meters, meaning there will be a lot fewer triangles created and it will move faster. If you are trying to see the indirect lighting on the person, the Init Detail value will be smaller, which means the huge surface areas of the walls and floor will produce huge numbers of 1 meter or less-sized triangles.

To see you triangle load, go to the Custom Rad Options dialog and press Start. I keep the number of emitting and receiving triangles below 150K for a reasonable render time.

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Those are the webpages rather than the actual images Jim. To find out the address of the actual image first click on "All sizes," then choose which size you want to use and then open the image in a new window and you'll see the address in the address bar.

There are many ways to open the image in a different window, depending on your browser software and system software. All I do is right-click on the image and choose "open in new window"

Here're your images:

145049168_42447788de.jpg

145049169_f97f633f5b.jpg

I used:

[img=http://static.flickr.com/48/145049168_42447788de.jpg]

[img=http://static.flickr.com/45/145049169_f97f633f5b.jpg]

Edited by Christiaan
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  • Vectorworks, Inc Employee

Hello again Jim:

The light instruments will also produce a lot of triangles, and these are not useful unless you really really want to see what indirect lighting you'll have up in the ceiling :-).

There are multiple ways to make those instruments not participate in radiosity, one is to select them and override radiosity to not emit and not receive. The other would be to use a radiosity bounds around your person, and another would be to apply a no emit no receive texture to the instruments. You can also turn down the detail settings on the instruments.

HTH,

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Dave,

The object of rendering stage lighting is the look of the lighting Q on the actors, dancers, and scenery. Since usually stages are dressed with black curtains, we do not want to see the walls, curtain, etc. The look should be as the RW looks. I tried to set the texture of the walls to not reflect, but I obviously did it wrong. Also why didn't my fog render in Rad like it did in RW?

The lighting instrument are black and not visable to the audience. I just haven't figred out hot to hide them. I am still learning rendering frown.gif

Jim

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  • Vectorworks, Inc Employee

Hello again Jim:

Select the lighting instrument, go to the Object Info palette -> Render pane. Scroll to the bottom and check Override Radiosity, uncheck Emit and uncheck Receive.

You should be able to do the same thing to the walls, leaving just the stage floor and the human figure.

The fog might not have rendered because the ambient was too high. Let me know what happens after the ambient is turned off.

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  • Vectorworks, Inc Employee

Hello again Jim:

It looks to me like the Lit Fog Density is too high. Try 1/10th or maybe even 1/100th the value that is set now.

Also, some distance falloff (Sharp is realistic but you will have to bump up the light brightnesses) would produce a more pleasing effect.

HTH,

Edited by Dave Donley
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Dave,

Ok lit fog at 25% on all three units - no change.

OH, any idea where the red is coming from? The only colors used are blue and no color!!

Still doesn't change the problem of not showing the beams of light as they are actually focused on stage. My problem is I use the renderings to show a director my vision of how the lighting will look at a perticular moment in the production. Not having the light levels correct or other modifcations does not accuately show my intentions for the lighting.

Maybe the answer is that Rad isn't the engine to use??

Anyother designers out the with thoughts?

Jim

145241089_b1b287cf21.jpg

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  • Vectorworks, Inc Employee

Hello again Jim:

Edit the RW Background resource's Max Density number. It defaults to 0.001. I'm saying to try 0.0001 or even 0.00001, since it looks to be too thick here. This needs to be turned down especially if you have accurate emitter values assigned to the lights (ex: lumens). What are the light brightnesses set to?

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  • Vectorworks, Inc Employee

Hello again Jim:

There will be a resource in the Resource Browser for this file that is a RenderWorks Background. This background is being applied to the layer to produce the lit fog effect. If you edit this resource you will see the Lit Fog weather choice and the parameter I mentioned above.

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  • Vectorworks, Inc Employee

Here are the steps I followed to render the above:

1. Go to the resource browser palette, look for the Render Background resources, and edit the Background-1 resource in that section. It has a Lit Fog weather assigned to it. The Max Density needs to be turned down to 0.0001. I also set the background to One Color with a black color.

2. The light objects created for Instruments have their distance falloff set to None, which is not realistic and doesn't render that great with lit fog. Until we provide more control in the instrument plug-in objects, you can get at the light objects created by the instruments and change their falloffs and brightnesses to look better. Duplicate each instrument in place, convert them to groups, edit the groups and delete everything but the light object and the optional gobo 3D polygon. When the light uses a gobo it creates a textured 3D polygon very close to the light object to cast the shadow. Set the light's falloff to Sharp, and the brightness % to 1000..5000. Sharp falloff is easier to use when the light object uses a real-world value in lumens for its brightness rather than a %. If you want to change the lights to lumens that might be easier, and if you know the lumen output of the actual light instruments you can simulate the real brightnesses that will be seen on the stage.

3. Turn off the lights in the remaining instrument PIOs, to avoid two lights being used for each instrument (the original and the modified duplicate light object).

4. When doing test renderings, turn down the Lit Fog's quality to Low (in the Render Background resource). Turn it back up for the final rendering.

5. You must use ray traced shadows, and have transparent shadows checked (Final Quality RW does this) for the gobos to project shadows.

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  • Vectorworks, Inc Employee

The strange rendering of the light cones is happening when Auto-Adjust Exposure is on. It is on by default for Fast and Final Quality Radiosity modes, but it can be turned off for Custom. This is a bug, and until I can fix it you need to turn off auto exposure in the Custom Radiosity dialog when you're rendering with lit fog. This problem might only happen in certain situations (it was tested and I have rendered scenes with both on before), so try rendering with auto exposure as the default first then turn it off if you see this problem.

To render this scene with radiosity, the easiest thing is to go to the Optimizations dialog in the Custom Radiosity Options dialog, and set the Other Objects option to Neither Emit Nor Receive. This removes all objects from the radiosity calculations except those with overrides. Then you can edit the stage floor's texture resource and set its Radiosity Options to always emit and receive. Then to get the figurine to receive light you can create a new texture resource and set its Radiosity Options to only receive. Then apply this texture to the figurine. I set the Init Detail to 2..4 feet, just to get the stage to bounce light up onto the mannequin.

HTH,

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Dave,

I appreciate your time on this.

WOW - will take some time to absorb all this - thanks for working on it. I will work on your suggestions and see how I do.

I guess one cannot just do a light plot and render a look with Rad. Maybe I will live with what RenderWorks produces??

Why is RAD so much more work than RW to render a scene?

Would you email me the plot back to me, with the changes you made, so I can work with it.

Again Thanks,

Jim

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Jim,

"Why is RAD so much more work than RW to render a scene?"

From the VW Help file:

"Radiosity is a rendering technique that models light energy transfer between drawing geometry and materials. Radiosity treats each section of drawing geometry as both an absorber and emitter of light. Light energy starts from the light sources present in the drawing; the surfaces that the light illuminates then re-emit the light energy, with changes to the light quality producing softer shadows, color "bleeding" between differently-colored surfaces (because a colored surface re-emits colored light), and softer, diffused lighting. The light energy bounces around until it stops producing an effect."

"It is possible for the radiosity solution to require too much detail or such high amounts of mesh data that the rendering cannot take place over a reasonable time period."

George

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George,

If you look at the first two images in the thread the second is one I did with RW. All I did was turn on the lights, set focus points and select gobos, then run custom RW and in 1 min I had a rendered Q from my light plot. Rad takes longer so it may not be right for my situation.

Looking at what Dave had to do to the same plot to get a Rad renderng it seems much more work.

My work is very fluid. I need to be able to create looks fairly quickly to show to the director or choreographer different looks on the spot.

I admit I haven't tried Dave's suggestions yet, but it appears to be more work. I pared this plot down from the orginal 120 units to these 7 to test out the two rendering programs.

So it is not just a rendering time factor.

Also I am trying to tech this to students.

Jim

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