OpenGL Computer Graphics 5

Question 1

What is the purpose of a Transform Feedback object in OpenGL?

Accepted Answer

Capturing vertex shader output into buffer objects for later use

Answer

Transform Feedback captures transformed vertex data (after the vertex/geometry stage) into VBOs, enabling GPU-side particle systems and simulation.

Question 2

What is the difference between GL_LINEAR and GL_NEAREST texture filtering?

Accepted Answer

GL_LINEAR blends adjacent texels (smoother), GL_NEAREST selects the closest texel (pixelated)

Answer

GL_NEAREST returns the texel whose center is nearest to the sample point, while GL_LINEAR interpolates between the four surrounding texels for smoother results.

Question 3

Which stage of the OpenGL pipeline converts primitives into fragments?

Accepted Answer

Rasterization

Answer

Rasterization converts geometric primitives (triangles, lines, points) into discrete fragments corresponding to screen pixels.

Question 4

What does the OpenGL function glUniform1i() do?

Accepted Answer

Sets an integer uniform variable in the currently active shader program

Answer

glUniform1i() uploads a single integer value to a uniform variable whose location was obtained with glGetUniformLocation().

Question 5

What is a Renderbuffer Object (RBO) in OpenGL and how does it differ from a texture attachment?

Accepted Answer

An RBO is an off-screen image optimized for rendering but not directly sampleable in shaders

Answer

Renderbuffer objects are write-only GPU image stores optimized for use as FBO attachments (depth/stencil), but cannot be sampled as textures.

OpenGL Practice Test

OpenGL Practice Test

OpenGL Computer Graphics 5