Quad rendering bug

[Ian]

What compile errors do you get

[HarryTuttle]

What compile errors do you get

Well, this is weird: I *used* to issue "-DSUPERMODEL_DEBUGGER" aside "-DDEBUG" compile option, until a version which I don't remember, otherwise it failed, that's why I've done the same until now to compile it (but Supermodel crashed as said before).

Now, just to try, I compiled with only "-DDEBUG" and worked!

Dunno what changed... anyway all seems to work well.

[HarryTuttle]

I think that the version that still needed "-DSUPERMODEL_DEBUGGER" with "-DDEBUG" was r576. After that the compiler threw this error:

Code: Select all

Compiling Src/OSD/SDL/Main.cpp...
Src/OSD/SDL/Main.cpp: In function 'void TestPolygonHeaderBits(IEmulator*)':
Src/OSD/SDL/Main.cpp:468:24: error: variable 'std::ofstream fs' has initializer but incomplete type
   std::ofstream fs(file);


But as of version r585 is fixed.

[Ian]

Yeah that was just a missing include, I had the same error in visual studio.
I did some debugging of this issue today. The hardware must be doing some calculation per poly to work out which way to split it. Since the independent quads, is no shared verts have this same issue. That rules out problems related to the order we are processing them.

Wonder if it uses the texture coordinates to work out which way to split

[Bart]

Glad it's working. For the record, I now know why it crashes. It's not the static_cast<> that's the problem. It's that the debugger is not aware of IEmulator and assumes it has a CModel3 object. It crashes when it tries to get the pointer to the DSB board, a function that CModel3GraphicsState doesn't even have. The explicit static_cast<>, by the way, is because gcc will complain that the ternary operator (?:) is being invoked with two different types (the derived classes). This graphcis state thing is really just a hacky dev thing so I'm okay with it being semi-broken.

Phew! The world makes sense again!

[HarryTuttle]

Phew! The world makes sense again!

Not too fast I started a new topic here: http://www.supermodel3.com/Forum/viewtopic.php?f=2&t=1369

[Ian]

been thinking about this problem a bit ..
This is essentially the problem with quads



The bottom one is generated by a geometry shader. Some code for that here -> http://www.informit.com/articles/articl ... 3&seqNum=2

I was wondering if we could do something very similar by splitting a quad into 4 triangles. We would need to calculate a new centre point, but that is pretty easy thankfully, just an average of the 4 points. We would also need to average the normals

[HarryTuttle]

That's why, I think, in one of the posted Harley images, the one with the red car very near the camera, the highlight on the side window appears to have a circular shape, instead of the square-shaped version of Supermodel.

[Ian]

I'll have a look
Edit
Can you take a screenshot of what you mean ?

[HarryTuttle]

left: Model 3, right: Supermodel

hl_02.jpeg (226.11 KiB) Viewed 7418 times

Edit:
the Supermodel's one has the "good" quad split