===== Transformation: Blending Union [Pasko and Savchenko 1994] =====
**Definition**: <m>R_uni(f1,f2) + disp(f1,f2,a0,a1,a2)</m>\\
<m>disp(f1,f2,a0,a1,a2)=a0/{1+(f1/a1)^2+(f2/a2)^2}</m>

**Call**: hfBlendUni(f1,f2,a0,a1,a2);

**Parameters**:

f1,f2 - two objects

a0,a1,a2 - blend parameters

**Test file**: [[http://hyperfun.org/blend.hf|blend.hf]]