Light an Object Properties - Setting auf Beam Angle/ Field Angle

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Permalink Reply by Render Plus on January 20, 2012 at 8:29am

I presume you are using a spot lamp from the IRender nXt lamp wizard:

Take a look at the steps below and see if it offers any help.

If not, be more specific about what you were tring to do and what results you got.

Here I placed a spot light at the top of a construction line, and then used "aim lamp" to aim it a Susan.

I then right clicked on the lamp and selected show-attributes to show the attributes saved on the lamp and it dhows the 30 degree beam angle.

I then changed the beam angle to 10 degrees by right clicking on the lamp, and selecting "Edit IRender Lamp"

Now when I right click for attributes - the new beam angle does not show up on the lamp definition, but rather on the lamp instance. Currently if you want to change the angle for the lamp definition (and all instances of the lamp), you will have to make a new lamp. Also, note, the "visible" beam on the lamp does not change - only the beam angle itself.

(New beam angle on Component Instance)

However the lamp with the narrower beam does render properly:

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Permalink Reply by Christoph Russ on January 24, 2012 at 12:41am

Hi Al,

thanks for your answer.

But I didn´t use the lamp wizard, I used the context menu - set object properties ... there is the "mistace".

Could you reproduce it?

chris

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Permalink Reply by Render Plus on January 24, 2012 at 7:07am

Sorry. I missed the words "Object Properties" in your original post.

If you are using Object Properties to create a spot light, then you should place to object properties on a small circular object - I you place it on the entire lamp, or a large surface than then entire object will be treated as a light.

It would help if you could upload a small .SKP model (e.g, the light and a surface to shine it on - like I did in my example) so I coud see what you did. Otherwise I will try an object properties example later today.

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Permalink Reply by Render Plus on January 26, 2012 at 9:40am

Here is a sample with object properties applied to a disk in the model.

First I set the disk to be a spot light to 30-degree beam and field using object properties.

Note: there are multiple light samples from the spot - because the disk itself is so large. This was 20 passes - with a light this large it would take hindreds of passes with the packet engine to get the smooth, soft, chadows which a large light source would create.

Then I right-clicked on the disk to change th object properties to a 10 degree spot:

And this produced the expected result (I let this one go 100 passes - but it would need more to converge properly.)

If this is not what you are getting, perhaps you can upload an image and a small model so we can see what you are trying to achieve.

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Permalink Reply by Render Plus on January 26, 2012 at 1:47pm

For the record - I lets this last rendering "cook" for 1,000 passes.

Now the lighting and shadows have converged pretty well. Note that there are soft, rather than sharp shadows. This is because the relatively large light source creates softer shadows. If you wanted sharp shadows, you would use a much smaller light source.

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