I want to draw custom stuff using my own webgl code and shaders.
Got into the CesiumWidget.prototype.render method and add a call to my function, so i will fit in.
I want to draw a simple point. in the shader simply multiply it by the modelViewProjection matrix uniform, and set the pointSize to 50.
My questions are:
1. Which values should i give my point ?
2. Where can i get the mvp matrix ?
I've tried this:
a. Setting the mvp matrix uniform to
b. And got my point values from the method viewer.scene.globe.ellipsoid.cartographicToCartesian(...)
And simply multiply them in the vertex shader
c. Canceled the depth test.
But the result is: When i roll and play with the globe, sometimes I see my point in the middle of the screen, and sometimes not..
is there a simple way to do it ? or should i copy all the complicated shaders and manipulate them to my needs?