Method, apparatus, and computer-readable recording medium for depth warping based occlusion culling
A method for performing occlusion queries is disclosed. The method includes steps of: (a) a graphics processing unit (GPU) using a first depth buffer of a first frame to thereby predict a second depth buffer of a second frame; and (b) the GPU performing occlusion queries for the second frame by using the predicted second depth buffer, wherein the first frame is a frame predating the second frame. In accordance with the present invention, a configuration for classifying the objects into the occluders and the occludees is not required and the occlusion queries for the predicted second frame are acquired in advance at the last of the first frame or the first of the second frame.
1. A method for performing occlusion queries, comprising steps of:
(a) a graphics processing unit (GPU) using a first depth buffer of a first frame to thereby predict a second depth buffer of a second frame; and
(b) the GPU performing occlusion queries for the second frame by using the predicted second depth buffer,
wherein the first frame is a frame predating the second frame;
wherein, at the step of (a), the GPU creates the predicted second depth buffer based on warping of the first depth buffer,
wherein, at the step of (a), the warping is a backward warping and the GPU performs the backward warping by using a hierarchical data structure of the first frame.
2. The method of claim 1 , further comprising the step of: (c) transmitting a result of the occlusion queries to a CPU.
3. The method of claim 1 , wherein, at the step of (b), the GPU performs the occlusion queries by using the predicted second depth buffer as an occluder map.
4. The method of claim 1 , wherein, at the step of (b), the occlusion queries are performed without classifying one or more objects of the second frame into occluders and occludees.
5. The method of claim 1 , wherein, at the step of (a), the GPU performs the warping of the first depth buffer by using a motion in at least either screen space or object space of the first frame or the second frame.
6. The method of claim 1 , wherein, at the step of (a), the GPU fills a hole generated at the predicted second depth buffer after the warping to the maximum depth.
7. The method of claim 1 , wherein the second frame includes one or more objects and, at the step of (b), the GPU processes the occlusion queries for the one or more objects in parallel.
8. One or more non-transitory computer-readable recording media having stored thereon a computer program that, when executed by one or more processors, causes the one or more processors to perform acts including:
(a) a graphics processing unit (GPU) using a first depth buffer of a first frame to thereby predict a second depth buffer of a second frame; and
(b) the GPU performing occlusion queries for the second frame by using the predicted second depth buffer,
wherein the first frame is a frame predating the second frame;
wherein, at the step of (a), the GPU creates the predicted second depth buffer based on warping of the first depth buffer,
wherein, at the step of (a), the warping is a backward warping and the GPU performs the backward warping by using a hierarchical data structure of the first frame.
9. A GPU, comprising:
a depth buffer rendering unit for using a first depth buffer of a first frame to thereby predict a second buffer of a second frame; and
an occlusion query unit for performing occlusion queries for the second frame by using the predicted second depth buffer;
a depth buffer warping unit for creating the predicted second depth buffer based on warping of the first depth buffer; and
wherein the warping is a backward warping, and the depth buffer warping unit performs the backward warping by using a hierarchical data structure of the first frame;
wherein the first frame is a frame predating the second frame in time.
10. The GPU of claim 9 , further comprising: a communication unit for transmitting a result of the occlusion queries to a CPU.
11. The GPU of claim 9 , wherein the occlusion query unit performs the occlusion queries by using the predicted second depth buffer as an occluder map.
12. The GPU of claim 9 , wherein the occlusion queries are performed without classifying one or more objects of the second frame into occluders and occludees.
13. The GPU of claim 9 , wherein the depth buffer warping unit performs the warping of the first depth buffer by using a motion in at least either on screen space or on object space of the first frame of the second frame.
14. The GPU of claim 9 , further comprising: a hole filling unit for filling a hole generated at the predicted second depth buffer after the warping to the maximum depth.
15. The GPU of claim 9 , wherein the second frame includes one or more objects, and the occlusion query unit processes the occlusion queries for the one or more objects in parallel.