In my vertex shader, I'd like to set the w component to 1.
How can this be done, after
gl_Position = MVP * vec4(vertexPosition_modelspace, 1); \$\begingroup\$ \$\endgroup\$
6 
- 5\$\begingroup\$ why do you think you need to? \$\endgroup\$ratchet freak– ratchet freak2018-01-29 14:49:24 +00:00Commented Jan 29, 2018 at 14:49
- \$\begingroup\$ I wanted to switch off perspective divide. \$\endgroup\$Edward– Edward2018-01-29 19:41:47 +00:00Commented Jan 29, 2018 at 19:41
- 1\$\begingroup\$ @Edward - "how do I switch off perspective divide?" might have been a better question then; ask about what you want to do, not how you want to do it. Further reading: meta.stackexchange.com/questions/66377/what-is-the-xy-problem \$\endgroup\$Maximus Minimus– Maximus Minimus2018-01-29 19:46:05 +00:00Commented Jan 29, 2018 at 19:46
- \$\begingroup\$ Then don't use a perspective projection but an orthographic projection matrix instead \$\endgroup\$ratchet freak– ratchet freak2018-01-29 20:37:37 +00:00Commented Jan 29, 2018 at 20:37
- \$\begingroup\$ I just wanted to see the effect switching it off had on a perspective projection. Seems to yield very similar results to an orthographic projection, when rendering a simple coloured cube. \$\endgroup\$Edward– Edward2018-01-29 22:30:14 +00:00Commented Jan 29, 2018 at 22:30
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1 Answer
\$\begingroup\$ \$\endgroup\$
You can use swizzles to access specific coordinates in the vector.
gl_Position.w = 1.0;
