What's Going On
apj commented on slide_028 of Radiometry ()

Could do absolute value instead of max if surface is double-sided, right?


gandalfzyq commented on slide_034 of Dynamics and Optimization (Part 1) ()

I have a question here, can the first equation also be applied to 3D? If yes, is u a vector3D in 3D space?


akanda commented on slide_027 of PerspectiveTexture ()

Here, in the 2nd bullet, "Divide by distance of a from line ca", shouldn't there be 'b' instead of 'a'?


akanda commented on slide_036 of Transforms ()

We can say that the bunny would then lie in the x-y plane


joycewang commented on slide_008 of Rasterization ()

how is the triangle's depth mapped to a grayscale value? is it proportional to the real distance between the triangle and the camera?


joycewang commented on slide_019 of PerspectiveTexture ()

can someone explain this to me please...


akanda commented on slide_043 of Math Part I ()

I think it depends on the the function u(x). Correct me if I am wrong: If u(x) is, say, 5, then, f(u) = 5 and for all x (0, 1), the map is uniform. However, if, say, u(x) = 5x, then, for all x (0, 1), it will be non-uniform for intermediate values


gandalfzyq commented on slide_062 of PerspectiveTexture ()

What is an anisotropic filtering like? How to combine multiple samples?


gandalfzyq commented on slide_027 of PerspectiveTexture ()

Is the mapping linear?


gandalfzyq commented on slide_036 of Transforms ()

If scaling x,y and w at the same time, it is like the bunny is scaled down to the origin?


gandalfzyq commented on slide_043 of Math Part I ()

This is not a linear map?


nsp commented on slide_032 of DrawTriangle ()

The triangles have different colors, so the shading difference lets you see which triangle is assumed to be "covering" the pixel for edge cases.


tony commented on slide_032 of DrawTriangle ()

What's the difference between the light gray and dark gray shading?


nsp commented on slide_033 of Math Part I ()

One thing you might try is breaking u and v into components along w and perpendicular to w, making an argument for these components separately, and then putting them all back together.


yidiz commented on slide_033 of Math Part I ()

Oh Sorry! I made a mistake there, where I thought u and v are pointing in the same direction. The right way would be calculating the area of parallelograms I think


nsp commented on slide_065 of DrawTriangle ()

I was not very clear about this in class because I confused the meaning of dX_i and dY_i. The slide is actually correct. What makes it work out:

-> Notice that dX_i is the difference between the X coordinate of P_{i+1} and P_{i} -> Similarly, dY_i is the difference between the Y coordinate of P_{i+1} and P_{i} -> Notice that the outward pointing normal n of this line is [ dY_i, -dX_i ]^T

Now the math works out to what I derived on the board: E_i(x, y) = E_i(q) = (q-P_0) . n

(sorry about the LaTex notation)


nsp commented on slide_003 of DrawTriangle ()

Location is NSH 3002


nsp commented on slide_002 of DrawTriangle ()

As I mentioned in class -- Assignment 0.0 is due today! Assignment 0.5 is due Wednesday.


nsp commented on slide_061 of Math Part I ()

Yes, thank you!


nsp commented on slide_033 of Math Part I ()

I see this for 4. How will you show 5 with similar triangles?


nsp commented on slide_027 of Math Part I ()

Numerical integration is very common in graphics, in part because we often do not have nice smooth functions for phenomena we represent or measure.


mahmoud commented on slide_061 of Math Part I ()

I found a small typo in this slide. The last row in the result matrix in the last bullet point should be (a_{1,z}u_{1} + a_{2,z}u_{2}).


yidiz commented on slide_033 of Math Part I ()

Both property 4 and 5 can be proved geometrically using similar triangles


oongaang commented on slide_027 of Math Part I ()

In general, this integral could be difficult to solve exactly. Will we have to use numerical integration techniques whenever we want L2 norms, or will most of our functions have integrals that are easy to compute?


nsp commented on slide_003 of Course Introduction ()

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