How to cut a circle in a polygon?

[Randy Johnson]

With that many small holes you should just use the alpha channel in the material, with displacement. It would take a life time to model that otherwise.

/Randy

[Siddharth Gautam singh]

Hi,

With wide shots the alpha solution works well. I am not sure if it would work very well with closeups.

This is how I would do it:

Take a circle spline, clone it using a grid array into the desired grid you want.
Then collapse the cloner object to get the splines (you will get a null object with all the splines as children). Now if the initial circle was a parametric object, you will have to select all the circles and convert them into splines as well.
Then with all the splines selected, do connect+delete.
You will get one single gird of circles spline.
Now if you want a rectangular grid, draw a rectangle around the grid of circles.
Make the rectangle editable (if not already).
Connect the grid and rectangle together.
Apply a Extrude Nurbs modifier.

Now this solution gives you real geometry. You can also bevel the edges of the circle grid easily.

[David Biederbeck]

Recently had to create a skateboard helmet and used alpha. Thanks for the clear and precise way to actually achieve the desired result!

[Craig Ricker]

Got a link to a good tut on how I use the alpha to make such a result by any chance?

[Craig Ricker]

Oh and thanks Sidharth, those instructions worked beautifully for the real geometry method!

[Siddharth Gautam singh]

Hi Craig,

This is what I achieved using an alpha map and displacement. What I did was to create a single grid cell using the extrude method and render it out. Then I used that image in the alpha and displacement channels, and then tiled it on to my model.

Tried using a normal map to get the bevel, but it was not working.

The mapping is a bit off and the displacement gets a bit crappy if you look closer, but it does a pretty good job I think.

Siddharth G Singh
Film | Motion | Illustration
http://www.siddharthgsingh.com

[Craig Ricker]

Wow looks good hey! But wasn’t sure what you meant by a single Grid cell with the extrude method?

[Siddharth Gautam singh]

I basically made one hole inside a square using splines and extrusion. I used the Falloff shader in the Luminance channel to get the ‘depth’ pass. I used this render in the alpha and displacement channels to create the grid in the image.

This can also be achieved just using gradients too I think.

Siddharth G Singh
Film | Motion | Illustration
http://www.siddharthgsingh.com