I want to thank the BRL-CAD and GOOGLE CODEIN to provide such
an opportunity.
After opt this task I used to saw the model of tennish ball and get on
the BRL-CAD for creating design. But I'm a beginner so I am unable to \
create srips on it.
I create it by following steps:-
step 1- firstly I open the mged and create a database named
           tennis.
step 2- after I make the mode view at axis.
step 3- I use the command to create a sphere shape
            < in 1 sph>
           entering its axises
            < 20 20 20>
           entering its radius 
            <20>
step 4- after I enter the command to change the color
            <r reg01 u 01> 
            mater reg01
step 5- I enter the RGB color as R 238, G 230, B 0 
step 6- I used the command to apply the color 
           <B reg01>
step 7- I enter the command for rendering 
            <rt>
step 8- I make it as in .PNG format   

It may be similar to all of your expectations.
Thank you.