What is the best way to create a lighting fixtures

[aufifillah alwi]

hi im new to vray for sketchup....no past experience in any kind of rendering software....

what is the best way to produce a real working lighting fixtures
that doesnt consume a lot of resource and time...
im using a physical camera with default visopt setting and ticking off the hidden light option

if im using the rectangular light the lighting fixture will not be visible. and if i use the emmisive one....it have a lot of splotch like shades all around the model ...
plz help me... :'( :'(
thx

[remon_v]

Re: What is the best way to create a lighting fixtures

The physical camera is to controll the exposure of the sun. Sunlight is really bright.
(You can find the sun under enviroment > GI skylight, click on the m and set it to sky).
When you use another light source like rectangular you have to set the multiplier really high.

[aufifillah alwi]

Re: What is the best way to create a lighting fixtures

The physical camera is to controll the exposure of the sun. Sunlight is really bright.
(You can find the sun under enviroment > GI skylight, click on the m and set it to sky).
When you use another light source like rectangular you have to set the multiplier really high.

and does setting the multiplier really high affect the render time?

[remon_v]

Re: What is the best way to create a lighting fixtures

Well the more lights you have in your scene the longer the render time.
Setting the multiplier high will give you brighter light. If you don't do this the light won't be visible, so yes longer rendertime.

If you have an exterior scene I would use sunlight.

[jrharvey]

Re: What is the best way to create a lighting fixtures

That is one thing that confuses the heck out of newbies to VRay. When I started using it I could not (and still dont) understand why the physical camera, physical sun, sky and lights cannot be already set so that they just work without having to adjust the multiplier. Im sure there was an important reason but its just odd sometimes I think.

[dalomar_cg]

Re: What is the best way to create a lighting fixtures

"...just working" is not really something that's feasible for the simple reason that setting those automatically would require us to divise an intent as to how those different features should contribute to your final rendering. I don't know about you, but that seams akin to a rendering "invasion of privacy"....let me spell out a few things for you.

The physical camera can change its exposure, and therefore can be set up so that a scene with the physical sun (a very bright light) is barely visible and a scene with the faintest of light is completely burned. Because of this, its complicates the situation significantly...and this is just the first piece of the puzzle.

The physical sun and sky will actually change the amount of illumination it generates based on where the sun actually is in the sky and other settings like turbidity will affect the final illumination as well. So the exposure settings that work well at high noon will lead to an under exposed image when the sun is almost on the horizon. This will vary quite a bit, so again this complicates the process of matching all of these parameters together.

When you light a scene, you determine where you want lighting to come from and the balance of the many lights that are usually in the scene. I really don't know how you could expect us to adjust the intensity of lights while keeping that design intent intact. Again, there actually isn't any guarantee that this will explicitly be needed, since the physical camera could certainly be properly exposed for the intensity o f lights at "normal" illumination levels.

The other silent players in all of this are the geometry that you're rendering, the materials, and where you're camera actually is within your scene. That makes even the same camera/sun setting almost impossible to guarantee that they'll be able to lend the comparable results from scene to scene, or even view to view depending on the way your model is set up.

The one thing that we can potentially do (and something that I've done at least some initial research on) is set up some sort of auto exposure system so that you at least wouldn't have to worry as much about setting everything within the physical camera. Regardless of how this gets actually done, it will still rely (to some extent) on rendering the scene, since the only way to get around the complexity of a scene, its lighting, and materials is to actually render it (in a limited or partial manner at least) and see how those interactions are playing out, and adjusting from there.

I guess to sum up, there are things that we could do to make working with the physical camera more manageable and possibly a little easier, but we will not be able to change how the system fundamentally works. Using the physical camera complicates the rendering process and requires a certain knowledge of photography and technical understanding of certain aspects of V-Ray. Rendering with the physical camera can be rewarding, but regardless of tools being available to help, the user must be willing to accept the change in workflow that it entails.

Lastly, and on a more personal note, the only way IMHO to really work with the V-Ray physical camera well and efficiently is to go out, pick up a REAL physical camera, and shoot in Manual for a while. Its only when you can play with different F-Stops, Shutter speeds, and ISO values that you will begin to actually grasp the connection of those settings to their affect on the images you take, and apply that to the renderings that you'll do. Besides, when you do that in the real world, you can get the result in a split second as opposed to waiting for a rendering.

[jrharvey]

Re: What is the best way to create a lighting fixtures

Im sorry, I didnt mean just work automatically, I mean work at all with the physical camera and standard lights. I do completely realize your whole point but setting the multi to 2,000 just to get a light to even show up on an interior scene is hard to understand for new people. I completely understand the difference between the physical camera and the standard but why does the physical camera need crazy high multipliers for things that don't have the prefix "physical". Is it not possible to get those numbers closer together? I remember one time I had to set a light multi to 2,500,000 one time just to get the correct lighting from it.
EDIT, I just noticed I was in the sketchup part so i dont know if its different there.

[aufifillah alwi]

Re: What is the best way to create a lighting fixtures

this is some of the work that i have been working on.....
i used the default visopt option and ticking off the hidden light..


im using emissive material to lit the fixture and then use the rectangular light for lit the area
pls tell me im doing the right thing....