Upgraded my game's line autobuilder so it can now build mixtures of arcs and straight lines, such as this half cylinder!
#gamedev
Amini Allight
@amini-allight.org
2K followers 761 following 663 posts
Solo game developer, VR enthusiast. Developing LambdaMod, a free and open source multiplayer game with VR support
![FragTransform correctNormals(vec3 position, vec3 normal)
{
mat4 model = object.model[gl_ViewIndex];
FragTransform result;
if (!roughly(dot(normalize(normal), normalize(position)), 0))
{
vec3 origin = (model * vec4(vec3(0), 1)).xyz;
vec4 fromLocalSpace = quaternionFromDirectionRoll(
normalize(position),
pickSideDirection(normalize(position))
);
vec4 toLocalSpace = quaternionInverse(fromLocalSpace);
vec3 localOrigin = quaternionRotate(toLocalSpace, origin);
vec3 localPosition = quaternionRotate(toLocalSpace, position);
vec3 localNormal = quaternionRotate(toLocalSpace, normal);
localPosition.y = localOrigin.y - (localPosition.y - localOrigin.y);
localNormal.y *= -1;
result.position = quaternionRotate(fromLocalSpace, localPosition);
result.normal = quaternionRotate(fromLocalSpace, localNormal);
}
else
{
result.position = position;
result.normal = normal;
}
return result;
}](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:233rdc7h3n232algrpopmzx3/bafkreiabdsnsrvfprqqhhxpfexbhzoilnzfrlg2zltkrm64equokm23kt4)
![layout(push_constant) uniform PushConstants {
uint stepCount;
uint aIndex;
uint bIndex;
} pushConstants;
layout(binding = 0) coherent buffer MyData {
float values[];
} myData[];
void main()
{
uint index = gl_GlobalInvocationID.x;
uint nextIndex = index + 1;
uint inputIndex = pushConstants.aIndex;
uint outputIndex = pushConstants.bIndex;
for (uint i = 0; i < pushConstants.stepCount; i++)
{
// do some work based on neighbors
myData[outputIndex].values[index] = myData[inputIndex].values[nextIndex];
// wait for neighbors to update
memoryBarrierBuffer();
// swap buffers
uint temp = inputIndex;
inputIndex = outputIndex;
outputIndex = temp;
}
}](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:233rdc7h3n232algrpopmzx3/bafkreieddbx6wc55btferdgpvqinr6km55syyecvpxkyjjomjuqwya73hq)
![The term "spiral" has a more narrow definition in a mathematical context, as a curve which lies in a single plane and moves towards or away from a central point, with a continuously changing radius. The mathematical term for the 3-dimensional curve traced where the locus progresses at a fixed radius from a fixed line while moving in a circular motion around it is a "helix". Since the very purpose of a stairway is to change elevation, it is inherently a 3-dimensional path.
Loose everyday usage conflates the terms helical and spiral, but the vast majority of circular stairs are actually helical.[15][16] True spiral staircases would be nonfunctional flat structures, although functional hybrid helical spiral staircases can be constructed. This article attempts to preferentially use the terms "helix" and "helical" to describe circular stairways more clearly and precisely, while reserving the term "spiral" for a curve restricted to a flat plane.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:233rdc7h3n232algrpopmzx3/bafkreievhygllxppov7amnbkqeaheghv7tgtzwniz7ipgpxskaxcfzuhdm)
