mitchellhansen/voxel-raycaster
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Lots of little tweaks as I figure out the octree. Fixed bug regarding the selects in the kernel dictating material texturing

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MitchellHansen
2017-08-19 00:04:10 -07:00
parent 4642ab8f0b
commit 9f764f4cbd
4 changed files with 48 additions and 27 deletions
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48
kernels/ray_caster_kernel.cl
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@@ -208,13 +208,16 @@ __kernel void raycaster(
// traverse an integer split
float3 delta_t = fabs(1.0f / ray_dir);
// offset is how far we are into a voxel, enables sub voxel movement
// Intersection T is the collection of the next intersection points
// for all 3 axis XYZ.
// delta_t * offset = intersection_t
float3 intersection_t = delta_t * ((*cam_pos) - floor(*cam_pos)) * convert_float3(voxel_step);
// for negative values, wrap around the delta_t
// for all 3 axis XYZ. We take the full positive cardinality when
// subtracting the floor, so we must transfer the sign over from
// the voxel step
float3 intersection_t = delta_t * ((*cam_pos) - ceil(*cam_pos)) * convert_float3(voxel_step);
// When we transfer the sign over, we get the correct direction of
// the offset, but we merely transposed over the value instead of mirroring
// it over the axis like we want. So here, isless returns a boolean if intersection_t
// is less than 0 which dictates whether or not we subtract the delta which in effect
// mirrors the offset
intersection_t -= delta_t * convert_float3(isless(intersection_t, 0));
int dist = 0;
@@ -258,6 +261,10 @@ __kernel void raycaster(
if (face_mask.x == -1) {
sign.x *= -1.0;
// the next intersection for this plane - the last intersection of the passed plane / delta of this plane
// basically finds how far in on the other 2 axis we are when the ray traversed the plane
float z_percent = (intersection_t.z - (intersection_t.x - delta_t.x)) / delta_t.z;
float y_percent = (intersection_t.y - (intersection_t.x - delta_t.x)) / delta_t.y;
@@ -332,18 +339,25 @@ __kernel void raycaster(
// }
// Now either use the face position to retrieve a texture sample, or
// just a plain color for the voxel color
voxel_color = select((float4)voxel_color,
(float4)(0.0f, 0.239f, 0.419f, 0.0f),
(int4)(voxel_data == 6));
// just a plain color for the voxel color. Notice the JANK -1 after the
// conditionals in the select statement. That's because select works on negs
// and pos's. So a false equality will still eval as true as it is technically
// a positive result (0)
voxel_color = select(
(float4)(0.25f, 0.64f, 0.87f, 0.0f),
(float4)voxel_color,
(int4)((voxel_data == 5) - 1)
);
voxel_color = select((float4)read_imagef(
texture_atlas,
convert_int2(tile_face_position * convert_float2(*atlas_dim / *tile_dim)) +
convert_int2((float2)(0, 0) * convert_float2(*atlas_dim / *tile_dim))
),
(float4)(0.0f, 0.239f, 0.419f, 0.0f),
(int4)(voxel_data == 5));
voxel_color = select(
(float4)(0.0f, 0.239f, 0.419f, 0.0f),
(float4)read_imagef(
texture_atlas,
convert_int2(tile_face_position * convert_float2(*atlas_dim / *tile_dim)) +
convert_int2((float2)(3, 0) * convert_float2(*atlas_dim / *tile_dim))
),
(int4)((voxel_data == 6) - 1)
);
voxel_color.w = 0.0f;