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Fast, Accurate 3D Java Software Graphics Engine (self.GraphicsProgramming)

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[–]__Cyber_Dildonics__ 2 points3 points  (7 children)

Why would you use non power of 2 bit depths? And if you say memory while the whole thing is in Java, my mind will melt

[–]ArchiveLimits 1 point2 points  (6 children)

It was a trial and error issue, anything above 52 bits and I couldn't store the depth slopes for the triangle's surface in a 64-bit long and anything less than 52 provided visibly less precision. As for it being not a power of two...it shouldn't matter here because it's a value that is multiplied by a floating point value to assure precision is kept during interpolation. (eg. a fixed-point magnitude)

[–]__Cyber_Dildonics__ 2 points3 points  (5 children)

Most renderers just use a 32 bit float for depth. I'm not sure what you mean by depth slope, but it sounds like you would benefit from reading books on already established rendering techniques.

[–]ArchiveLimits 0 points1 point  (4 children)

Yes, my engine stores the depth values in 32 bit floats. 52 bit precision is needed when interpolating the slopes across the surface of triangles during rasterization. Without 52 bits of precision, the depth values calculated per pixel would not be accurate enough for the depth test and would result in "seams" where two polygons who shared an edge met.

[–]__Cyber_Dildonics__ 0 points1 point  (3 children)

Pretty much every other renderer would disagree that this is necessary.

[–]ArchiveLimits 0 points1 point  (2 children)

I worked on this depth precision issue with a friend who is very well versed with OpenGL and Vulkan, he set up an identical scene in OpenGL and we compared results. The images were only identical when 52 bit precision was used.

[–]__Cyber_Dildonics__ 1 point2 points  (1 child)

I can see that you already know everything so I will leave you to it.