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Type: Posts; User: Yandersen

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1. ## Thread: Seamless triangular patches

by Yandersen
Replies
2
Views
2,177

### Here is an application in the attachment...

Here is an application in the attachment demonstrating two independent surfaces constructed from two random triangles (random vertices and normals) with one common edge. Surfaces are built...
2. ## Thread: Seamless triangular patches

by Yandersen
Replies
2
Views
2,177

### Indeed, it works for surfaces with level 7 and...

Indeed, it works for surfaces with level 7 and above! But it requires 2 corner panels to shrink into degenerate triangles to fully break the dependency between triangle's edges. There is more to...
3. ## Thread: Seamless triangular patches

by Yandersen
Replies
2
Views
2,177

### Seamless triangular patches

Hi!
Recently I found a very helpful paper describing how to make the edge between triangular bezier patches match with the desired level of continuity:...

by Yandersen
Replies
18
Views
3,486

### Success! In order to calculate the normal I use...

Success! In order to calculate the normal I use the second service curve created by shifting the control points of the original one. The resulting normal is calculated as a cross-product of a tangent...

by Yandersen
Replies
18
Views
3,486

### Well, I do need continuity across edges so two...

Well, I do need continuity across edges so two patches sharing two PN-handles can be stacked together without a visible seem. And my approach makes it so - I just checked it with two patches -...

by Yandersen
Replies
18
Views
3,486

### I just confirmed that the function...

I just confirmed that the function TessellateCurve incorrectly computes the normal Nm for the subdivision point Vm. But I have no idea how to do that the right way... If I simply interpolate it using...

by Yandersen
Replies
18
Views
3,486

### Well, there is a way to subdivide a surface using...

Well, there is a way to subdivide a surface using iterative approach and still get a desired smooth shape. The trick is to use the initial control points whenever a new vertex added. But in order to...

by Yandersen
Replies
18
Views
3,486

### Sadly, you must be right... Say, we have a...

Say, we have a curve, which shape is defined by 2 PN control points. The shape of that curve actually differ depending on the length we choose for the tangents - we can...

by Yandersen
Replies
18
Views
3,486

### For those who might care - an update: #include...

For those who might care - an update:

#include "GLSL.hpp" //GLSL vectors, matrices, operators and functions

//Function breaks an edge onto two by inserting an extra point inbetween the...

by Yandersen
Replies
18
Views
3,486

### Oh yes, now I see, thank you! Funny, but, the...

Oh yes, now I see, thank you! Funny, but, the more we talk about it the more precise the "However you like." answer looks like to me... :) There is clearly a whole bunch of solutions to make a...

by Yandersen
Replies
18
Views
3,486

### I think I found the solution here...

I think I found the solution here. As I understood from the video, the "tension line" is tangent to the curve, and the coordinates of the desired point Vm is a center of that line at 50%...

by Yandersen
Replies
18
Views
3,486

### Wow, wow, GClements, you always shoot so much...

Wow, wow, GClements, you always shoot so much theoretic material for my simple mind that I start feel myself like a black guy in a science lab... :)
I've seen this triangle subdivision with extra 7...

by Yandersen
Replies
18
Views
3,486

### It is an edge of the triangle. I tessellate the...

It is an edge of the triangle. I tessellate the triangle by subdividing it's edge.

by Yandersen
Replies
18
Views
3,486

### Whoops, I just realized I have incorrectly...

Whoops, I just realized I have incorrectly specified the problem. We can't say that the normal Nm in the middle point Vm will be the average between normals Na and Nb. Attachment is an example were...

by Yandersen
Replies
18
Views
3,486

### Oh, thank you, GClements, it works! :) Care to...

Oh, thank you, GClements, it works! :)
Care to explain why the displacement divided specifically by 8?

by Yandersen
Replies
18
Views
3,486

### Tesselate triangle

Hi!
Say, I want to increase detalization of a mesh to make a model smoother.

I want to do this by a simple iterative approach: if a certain edge with vertices Va and Vb and normals Na and Nb has...
17. ## Thread: Intersect triangle with segment

by Yandersen
Replies
5
Views
1,567

### Thank you, GClements, indeed the algorithm gives...

Thank you, GClements, indeed the algorithm gives the same result for intersection point. I manually checked conditions - no_intersection_conditions reported correctly ("false" returned). I rewrote...
18. ## Thread: Intersect triangle with segment

by Yandersen
Replies
5
Views
1,567

### Wow... That is too much for me, I guess... I...

Wow... That is too much for me, I guess... I solved the problem geometrically, through relativity of the volumes (which is calculated as a determinant of 3x3 matrix composed of three vectors forming...
19. ## Thread: Intersect triangle with segment

by Yandersen
Replies
5
Views
1,567

### Intersect triangle with segment

Hi!
Basic task - to find the intersection point between a line segment with corner points S1 and S2 and a triangle with vertices A,B,C.

To do this I wrote a function that calculates partial...
20. ## Thread: glTextureSubImage2D vs GL_TEXTURE_CUBE_MAP

by Yandersen
Replies
4
Views
2,368

### Clearly, that was one of a hundreds...

Clearly, that was one of a hundreds typos/mistakes I mentioned for a last few month. The whole docs have to be "bulldozered", function-by-function.
21. ## Thread: glTextureSubImage2D vs GL_TEXTURE_CUBE_MAP

by Yandersen
Replies
4
Views
2,368

### Thank you, Alfonse! P.S.: man4 pages have more...

Thank you, Alfonse!

P.S.: man4 pages have more bugs than information. Shame no one maintains the documentation.
22. ## Thread: glTextureSubImage2D vs GL_TEXTURE_CUBE_MAP

by Yandersen
Replies
4
Views
2,368

### glTextureSubImage2D vs GL_TEXTURE_CUBE_MAP

Hello!
In OpenGL4.5 we got DSA providing the alternative texture uploading functions that take a texture ID instead of the target as a parameter:

void glTextureSubImage2D(
GLuint texture,
...
23. ## Thread: Lines at the end of a texture

by Yandersen
Replies
10
Views
1,922

### Seems like the target implementation does not...

Seems like the target implementation does not support non-POT textures? Nowadays?! :O
24. ## Thread: opengl draw lines doubt

by Yandersen
Replies
4
Views
1,141

### You are welcome, but it should. :) Would you...

You are welcome, but it should. :)
Would you post a line-drawing part of code?
25. ## Thread: Lines at the end of a texture

by Yandersen
Replies
10
Views
1,922

### Check wrapping parameters (GL_TEXTURE_WRAP_S,...

Check wrapping parameters (GL_TEXTURE_WRAP_S, GL_TEXTURE_WRAP_T) - maybe you see pixels from the opposite side of the image while you prefer edge clamping (GL_CLAMP_TO_EDGE)?
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