cannot create pdf using wkhtmltopdf

gistfile1.txt

$ cd sinatra-book/
$  bundle exec rake book:build --trace
** Invoke book:build (first_time)
** Execute book:build
/home/irasally/sinatra-book/vendor/wkhtmltopdf: error while loading shared libraries: libXrender.so.1: cannot open shared object file: No such file or directory
rake aborted!
command failed: "/home/irasally/sinatra-book/vendor/wkhtmltopdf" "--page-size" "Letter" "--margin-top" "0.75in" "--margin-right" "0.75in" "--margin-bottom" "0.75in" "--margin-left" "0.75in" "--encoding" "UTF-8" "--quiet" "-" "-"
/home/irasally/.rvm/gems/ruby-1.9.3-p286@sinatra-book/gems/pdfkit-0.5.2/lib/pdfkit/pdfkit.rb:71:in `to_pdf'
/home/irasally/sinatra-book/book.rb:21:in `build'
/home/irasally/sinatra-book/Rakefile:7:in `block (2 levels) in <top (required)>'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/home/irasally/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/bin/rake:19:in `load'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/bin/rake:19:in `<main>'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/bin/ruby_noexec_wrapper:14:in `eval'
/home/irasally/.rvm/gems/ruby-1.9.3-p286@global/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => book:build

# search libXrender
$ ls /usr/lib | grep libXrender*  
// nothing
$ ls /usr/lib64 | grep libXrender*
libXrender.so.1
libXrender.so.1.3.0

# os infomation
$ uname -a
Linux ipagrid6 2.6.32-279.11.1.el6.x86_64 #1 SMP Tue Oct 16 15:57:10 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
$ cat /etc/redhat-release
CentOS release 6.3 (Final)

Do I need symlink?